Entries |
Document | Title | Date |
20080225558 | Amplifier with switchmode power supply - An amplifier is driven by DC voltage from a switchmode power supply, whereby the switchmode power supply includes on the primary side a primary winding and bias supply winding. The bias supply winding supplies a reflected voltage from a secondary winding to a bias supply capacitor. The bias supply capacitor drives the control circuit and provides a sensing to the control circuit. The power supply further includes an active clamp circuit for controlling the voltage stress on a main switch. In another embodiment, boost inductors and a balancing transformer are added on the primary side of the transformer to prevent overvoltage conditions at light loads. | 09-18-2008 |
20090040795 | METHOD AND APPARATUS FOR INCREASING THE POWER CAPABILITY OF A POWER SUPPLY - Techniques are disclosed to extend an on time period of switch to regulate a transfer of energy from an input of a power supply to an output of a power supply. One example integrated circuit includes an energy transfer element coupled between an input and an output of the power supply. A switch is coupled to the input of the energy transfer element. A controller is coupled to the switch to control switching of the switch to regulate a transfer of energy from the input of the power supply to the output of the power supply in response to a feedback signal received from the output of the power supply. The controller is coupled to limit a maximum on time period of the switch a first maximum on time period in response to a first range of power supply operating conditions and to a second maximum on time period for a second range of power supply operating conditions. | 02-12-2009 |
20090175057 | ISOLATED VOLTAGE CONVERTER WITH FEEDBACK ON THE PRIMARY WINDING, AND CORRESPONDING METHOD FOR CONTROLLING THE OUTPUT VOLTAGE - An embodiment of a voltage converter includes: voltage-transformer means having a primary side, designed to receive an input voltage, and a secondary side, designed to supply an output voltage; control-switch means coupled to said primary side; and a control circuit, coupled to a control terminal of said control-switch means and designed to control switching thereof as a function of a first signal correlated to said output voltage; said control circuit being provided with an error-amplifier stage, designed to process a difference between said first signal and a reference signal, wherein said error-amplifier stage is configured so as to have a transconductance characteristic with a linear-operation region, having a given slope, and at least one first clamped region, which has a slope lower than said given slope and is contiguous to said linear-operation region. | 07-09-2009 |
20090196076 | INTEGRATED BASE DRIVER AND SWITCHING WINDINGS FOR AN ESBT POWER DRIVER - A power supply circuit includes: a switching flyback transformer having a primary winding and a secondary winding; a current transformer having a primary winding and a secondary winding; and a switching transistor have a conduction path and a control terminal. The primary winding of the switching flyback transformer, the primary winding of the current transformer and the conduction path of the switching transistor are coupled together in a series circuit. The switching flyback transformer and the current transformer share a common core. The windings of the switching flyback transformer may be wound around one leg of the common core, while the windings of the current transformer may be wound around a different leg of the common core. | 08-06-2009 |
20090201701 | COMPENSATION FOR PARAMETER VARIATIONS IN A FEEDBACK CIRCUIT - Techniques to compensate for parameter variations in a feedback circuit are disclosed. In one embodiment, a regulator circuit includes an energy source coupled to output a generated current in response to a control current. A feedback resistor is coupled to an output of the regulator circuit. The feedback resistor is coupled to conduct a feedback current responsive to the output of the regulator circuit. A current amplifier is coupled to the feedback resistor to generate the control current in response to the feedback current. A compensation network is coupled to the current amplifier to adjust the control current in response to an extrinsic parameter of the regulator circuit. The compensation network includes a transistor and first, second and third resistors. The first resistor is coupled between the feedback resistor and a collector of the transistor. The second resistor coupled between the collector and the base of the transistor. The third resistor coupled between the base and an emitter of the transistor. | 08-13-2009 |
20090257251 | Switching control circuit for a switching power converter - A switching control circuit is coupled to a switching device and an auxiliary winding of a transformer, wherein a primary winding of the transformer is coupled to the switching device. The switching control circuit includes a voltage receiver, a comparing unit and a propagation delay circuit, wherein the voltage receiver is coupled to the auxiliary winding of the transformer for receiving a reflected voltage signal and transforming the reflected voltage signal into a peak voltage signal, while the switching device is turned off. The comparing unit is coupled to the voltage receiver for receiving the peak voltage signal and a first threshold voltage, and outputting a comparison result. The propagation delay circuit is coupled to the comparing unit for receiving the comparison result, and outputting a PWM signal to turn on the switching device after a delay time. | 10-15-2009 |
20090310389 | METHOD AND APPARATUS PROVIDING A MULTI-FUNCTION TERMINAL FOR A POWER SUPPLY CONTROLLER - A method for controlling a power supply is disclosed. An example method includes deactivating the power supply in response to a first current through a first terminal of a power supply controller falling below a first threshold value. The power supply is activated in response to the first current through the first terminal rising above a second threshold value. Deactivating the power comprises causing a power switch coupled to a primary winding of the power supply not to receive a switching waveform for more than one cycle until the power supply is activated. | 12-17-2009 |
20100008108 | NOVEL ADAPTIVE SLOPE COMPENSATION METHOD FOR STABILIZING A CONTINUOUS CONDUCTION MODE CONVERTER - An embodiment of the invention relates to a power converter operable in a continuous conduction mode and a discontinuous conduction mode that includes a current-sense circuit element configured to produce a current-sense signal dependent on a current in an inductor of the power converter, and a difference circuit configured to produce a difference signal representing a difference of the current-sense signal and a signal representing an output characteristic of the power converter such as an output voltage. The difference signal is constrained to be above a difference signal threshold value. A slope compensation circuit is configured to produce a slope-compensated signal comprising a sum of the difference signal and the current-sense signal. A controller is configured to control a duty cycle of a power switch of the power converter in response to the slope-compensated signal by comparing the slope-compensated signal with a voltage threshold controlled by a feedback circuit. | 01-14-2010 |
20100027299 | SYSTEMS AND METHODS FOR ADAPTIVE SWITCHING FREQUENCY CONTROL IN SWITCHING-MODE POWER CONVERSION SYSTEMS - Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage and a secondary winding coupled to the primary winding. Additionally, the system includes a compensation component configured to receive the input voltage and generate at least a clock signal based on at least information associated with the input voltage, and a signal generator configured to receive at least the clock signal and generate at least a control signal based on at least information associated with the clock signal. Moreover, the system includes a gate driver configured to receive at least the control signal and generate a drive signal based on at least information associated with the control signal, and a first switch configured to receive the drive signal and affect a first current flowing through the primary winding. | 02-04-2010 |
20100142231 | Control Methods and Integrated Circuits for Controlling Power Supply - Integrated circuits for controlling power supplies and relevant control methods are disclosed. A controller generates a control signal to control a power switch. A feedback pin of an integrated circuit receives an external feedback signal representing an output voltage signal of a power supply. Controlled by the control signal, a transferring circuit transfers the feedback signal to the controller when the power switch is off. When the power switch is on, a clamping circuit clamps the voltage of the feedback signal at a predetermined value to avoid the controller from being influenced by the feedback signal. | 06-10-2010 |
20100232187 | OUTPUT VOLTAGE CONTROL CIRCUIT OF POWER CONVERTER FOR LIGHT-LOAD POWER SAVING - A control circuit of a power converter for light-load power saving according to the present invention comprises a first feedback circuit coupled to an output voltage of the power converter to receive a first feedback signal. A second feedback circuit is coupled to the output voltage to receive a second feedback signal. A control circuit generates a switching signal for switching a transformer of the power converter and regulating the output voltage of the power converter in response to the first feedback signal and the second feedback signal. The switching signal is generated in accordance with the first feedback signal when an output load is high. The switching signal is generated in accordance with the second feedback signal during a light-load condition. | 09-16-2010 |
20100232188 | POWER SUPPLY APPARATUS - In a power supply apparatus, a current limitation unit configured to detect a current flowing through a primary winding of a transformer to limit a current to a switching unit has a self-holding unit configured to self-hold a state where the current to the switching unit is limited. | 09-16-2010 |
20100271849 | Flyback constant voltage converter having both a PWFM mode and a PWM mode - A flyback AC/DC switching converter has a constant voltage (CV) mode. The CV mode has sub-modes. In one sub-mode (“mid output power sub-mode”), the output voltage (VOUT) of the converter is regulated using both pulse width modulation and pulse frequency modulation. Both types of modulation are used simultaneously. In a second sub-mode (“low output power sub-mode”), VOUT is regulated using pulse width modulation, but the converter switching frequency is fixed at a first frequency. By setting the first frequency at a frequency above the frequency limit of human hearing, an undesirable audible transformer humming that might otherwise occur is avoided. In some embodiments, the converter has a third sub-mode (“high output power sub-mode”), in which pulse width modulation is used but the switching frequency is fixed at a second frequency. By proper setting of the second frequency, undesirable EMI radiation and other problems that might otherwise occur are avoided. | 10-28-2010 |
20110013426 | SNUBBER CAPACITOR GENERATING AN AUXILLARY POWER SUPPLY VOLTAGE - An integrated circuit (IC) forming a pulse-width modulator controls the switching operation of an output stage of a switching power supply. A snubber capacitor that is coupled to a primary winding of a transformer of the output stage is used for producing a capacitive coupled charging current. The capacitive coupled charging current is coupled to a filter or charge storage second capacitor for producing in the second capacitor a first portion of a second power supply voltage. During a portion of a switching cycle of the output stage, the snubber capacitor is coupled to an inductor to form a resonant circuit. The resonant circuit produces in the second capacitor a second portion of the second power supply voltage for energizing the IC. The second power supply voltage is used for energizing the IC. | 01-20-2011 |
20110026278 | CURRENT-CONTROLLED SELF-OSCILLATING FLYBACK CONVERTER WITH TWO TRANSISTORS - A current controlled self-oscillating flyback converter with two transistors. The converter includes a soft start circuit, a MOS transistor, a transformer, a pulse frequency modulation circuit, a reference amplification circuit, an isolation optical coupler and a voltage-stabilized output circuit. The pulse frequency modulation circuit includes a transistor, a third resistor, a capacitor connected in parallel with the third resistor and a fourth resistor. The pulse frequency modulation circuit further includes a transistor current control circuit. The control circuit is connected between the MOS transistor and the transistor. | 02-03-2011 |
20110051470 | SWITCHING MODE POWER SUPPLIES AND ASSOCIATED METHODS OF CONTROL - Switching mode power supplies and associated methods of control are disclosed herein. In one embodiment, a method for controlling a switching mode power supply includes determining whether the switching mode power supply is in a burst mode. If the switching mode power supply is in the burst mode, the method includes recording a switching time with and without switching pulses to obtain a current value of an equivalent frequency and generating a peak current limit that decreases as a load becomes lighter based on the equivalent frequency, thereby maintaining the equivalent frequency at the current value above an audible range. If the switching mode power supply is not in the burst mode, the method includes continuing to monitor whether the switching mode power supply is in the burst mode. | 03-03-2011 |
20110103103 | POWER SUPPLY WITH LOW POWER CONSUMPTION HICCUP STANDBY OPERATION - A power supply including a converter, a capacitance, and a hiccup control module. The converter converts an input voltage to both an output voltage and a preliminary standby voltage when in its active state. The capacitance stores the preliminary standby voltage which is charged to an upper voltage level when the converter is in its active state and which is discharged to a lower voltage level when the converter is in its inactive state. During the standby mode, the hiccup control module operates the converter in hiccup mode by toggling between placing the converter into its inactive state when the preliminary standby voltage is charged to the upper voltage level and placing the converter into its active state when the preliminary standby voltage is discharged to the lower voltage level. The hiccup mode of the power supply eliminates a need for a separate standby converter. | 05-05-2011 |
20110157924 | Using output drop detection pulses to achieve fast transient response from a low-power mode - In a first aspect, in a Primary Side Regulation (PSR) power supply, some primary current pulses are used to forward bias an output diode such that an auxiliary winding voltage can be properly sampled after each pulse. The samples are used to regulate the power supply output voltage (VOUT). Other primary current pulses, however, are of a smaller peak amplitude. These pulses are not used for VOUT regulation, but rather are used to determine whether the VOUT has dropped. In a second aspect, a transient current detector circuit within the PSR controller integrated circuit detects whether an optocoupler current has dropped in a predetermined way. If the TRS current detector detects that the optocoupler current has dropped, then the power supply stops operating in a sleep mode and is made to operate in another higher power operating mode in which the power supply switches. | 06-30-2011 |
20110188271 | SWITCHING REGULATOR DEVICE - A switching regulator device including a power conversion transformer for converting an input voltage from a power source at a primary side to a predetermined output voltage and outputting the output voltage to a load circuit connected to a secondary side, a power converter circuit that has a primary-side circuit and a secondary-side circuit insulated from each other, and transmits a load driving control signal input to the primary-side circuit through the secondary-side circuit to the load circuit, and a feedback circuit that performs feedback control on the output voltage on the basis of feedback current generated at the primary side of the power conversion transformer, a part of the feedback current of the feedback circuit being consumed in synchronism with the load driving control signal. | 08-04-2011 |
20110194314 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device including: a power transformer including a primary winding, a secondary winding, and an auxiliary winding; a switching element which is connected to the primary winding; an output voltage generation circuit which converts, into a direct-current voltage, a voltage induced in the secondary winding; a secondary-side on-time signal generation circuit which generates a secondary-side on-time signal indicating a secondary-side on-time; and a switching control circuit which controls a switching operation of the switching element so that the second direct-current voltage falls within a specified range, wherein the switching control circuit controls the switching operation so that the direct-current voltage becomes equal to or below an overvoltage specified value when the secondary-side on-time becomes smaller than a set value. | 08-11-2011 |
20110205765 | INDUCTANCE ELEMENT, METHOD FOR MANUFACTURING THE SAME, AND SWITCHING POWER SUPPLY USING THE SAME - An inductance element ( | 08-25-2011 |
20110216560 | TWO STAGE ISOLATED SWITCH-MODE AC/DC CONVERTER - An AC/DC two stage converter includes a non-isolated switch-mode regulated AC/DC voltage step-down first stage converter comprising an AC input and a first DC output. The AC voltage applied to the AC input is rectified and switch-mode regulated to a first DC voltage at the first DC output. The first DC voltage is lower than a peak voltage of the AC voltage applied to the AC input. An isolated switch-mode regulated DC/DC second stage converter includes a second DC input coupled to the first DC output and at least one second DC output, wherein the first DC voltage is switch-mode regulated to a second DC voltage at a second DC output. | 09-08-2011 |
20110255311 | FLYBACK CONVERTER SYSTEM AND FEEDBACK CONTROLLING APPARATUS AND METHOD FOR THE SAME - A flyback converter system and feedback controlling apparatus and method of operating the same are disclosed. The feedback controlling apparatus for the flyback converter system includes a primary feedback loop unit for generating a primary feedback signal, and a secondary feedback loop unit for generating a secondary feedback signal, a loop selector. In light-load conditions, the loop selector supplies the primary feedback signal to a PWM controller for feedback control, and the secondary feedback loop unit is disabled by a power monitor to save electrical energy. | 10-20-2011 |
20110292692 | OPTO-COUPLED SENSING - The present invention provides an isolated regulating power converter with opto-coupled feedback of output (Vo) with respect to a reference level (Vset) for regulation to a converter controller. The sense of the feedback signal is such that the opto-coupler LED is ON when VoVset with the effect that the LED current and power loss is zero during the times when Vo>Vset, as is normal case for many controllers at low or no load. This saves power under such circumstances. Additionally, as the LED does not load the output during this time, the proportion of time for which Vo>Vset is increased, meaning that the timing at which the switch must again be on to meet demand is extended, producing a further power saving. | 12-01-2011 |
20110299306 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT RESPONSIVE TO AN IMPEDANCE COUPLED TO A CONTROL CIRCUIT TERMINAL - An example power supply controller includes a regulation circuit, a current sense circuit, and a response circuit. The regulation circuit is coupled to regulate a sense terminal to a voltage level. The current sense circuit is coupled to the sense terminal to sense a current through the sense terminal a measurement delay period after a magnitude of the current through the sense terminal reaches a first threshold current level. The response circuit is coupled to the sense circuit and is responsive to the current through the sense terminal only after the measurement delay period. | 12-08-2011 |
20120008345 | APPARATUS AND METHOD FOR OUTPUT VOLTAGE CALIBRATION OF A PRIMARY FEEDBACK FLYBACK POWER MODULE - An apparatus and method for output voltage calibration of a primary feedback flyback power module extract the difference between the output voltage of the power module and a target value, and according thereto, calibrate a reference voltage which is used in regulation of the output voltage, to thereby calibrate the output voltage to be the target value. | 01-12-2012 |
20120008346 | SEMICONDUCTOR INTEGRATED CIRCUIT AND SWITCHING POWER SUPPLY SYSTEM - A control circuit can be provided with a comparator detecting a turning-off of a semiconductor switch from a voltage generated in an auxiliary winding of a transformer and inputted to a zero current detecting terminal, a timer outputting a signal after a specified length of time from the time at which the turning-off of the semiconductor switch is detected, and a comparator detecting from voltages inputted to a current detecting terminal a second voltage signal different from an ordinary first voltage signal inputted when the semiconductor switch is made turned-on. Thus, the second voltage signal supplied from mode switching circuits as an externally inputted mode switching signal can be made also detected by the existing current detecting terminal. By detecting the second voltage signal after the specified length of time from the turning-off of the semiconductor switch, switching of an operation mode becomes possible without newly providing any specialized terminal. | 01-12-2012 |
20120026759 | ULTRA LOW STANDBY CONSUMPTION IN A HIGH POWER POWER CONVERTER - A power converter with low power consumption during a standby operating condition. An example power controller includes a main converter coupled to a dc input of the power converter to control a transfer of energy from the dc input of the power converter to a main output of the power converter. A standby converter is also included and is coupled to the dc input of the power converter to control a transfer of energy from the dc input of the power converter to a standby output of the power converter during a standby operating condition of the power converter. A standby circuit is also included and is coupled to the dc input of the power converter and coupled to the main converter. The standby circuit decouples the main converter from the dc input of the power converter during the standby operating condition of the power converter. | 02-02-2012 |
20120147630 | SYSTEM AND METHOD PROVIDING OVER CURRENT PROTECTION BASED ON DUTY CYCLE INFORMATION FOR POWER CONVERTER - System and method for protecting a power converter. The system includes a duty-cycle detection component configured to receive a modulation signal, determine a first duty cycle corresponding to a first period of the modulation signal, compare the first duty cycle with a threshold duty cycle, and generate a duty-cycle comparison signal. Additionally, the system includes a threshold generator configured to receive the duty-cycle comparison signal and generate a threshold signal corresponding to a second period of the modulation signal, the second period being after the first period, and a comparator configured to receive the threshold signal and a first signal and to generate a first comparison signal. The first signal is associated with an input current for a power converter. Moreover, the system includes a pulse-width-modulation component configured to receive the first comparison signal and generate the modulation signal for adjusting the input current for the power converter. | 06-14-2012 |
20120147631 | DC/DC CONVERTER, AND POWER SUPPLY AND ELECTRONIC DEVICE USING THE SAME - A DC/DC converter includes a transformer including primary and secondary coils and an auxiliary coil disposed in a primary coil side; a first output capacitor including a first end having a fixed electric potential and a second end; a first diode disposed in a direction where a cathode of the first diode faces the first output capacitor, between the second end of the first output capacitor and one end of the secondary coil; a switching transistor disposed on a path of the primary coil; a second output capacitor including a first end having a fixed electric potential and a second end; a second diode and a switch disposed between the second end of the second output capacitor and the first port of the auxiliary coil; and a control circuit receiving voltage generated in the second output capacitor through a power supply port and controlling turn-on/off of the switching transistor. | 06-14-2012 |
20120155122 | CONTROLLER AND CONTROLLING METHOD FOR POWER CONVERTER - A controller for a power converter is provided. The controller includes a sense current integrating circuit, a reference current integrating circuit and a drive signal generation circuit. The sense current integrating circuit performs an integrating operation to a sense current representative of a conduction current flowing through a power switch of the power converter and thereby outputs a first integrating result. The reference current integrating circuit performs another integrating operation to a reference current and thereby outputs a second integrating result. The drive signal generation circuit determines a switching period of the power switch according to a status of an output voltage of the power converter cooperative with a relative magnitude relationship between the first integrating result and the second integrating circuit. Furthermore, a controlling method for such power converter also is provided. | 06-21-2012 |
20120155123 | REVERSE SHUNT REGULATOR - A reverse shunt regulator includes a MOSFET connected between a cathode and an anode, a switch and a current source serially connected between the cathode and the anode, and an error amplifier having a positive input node to receive an internal reference voltage, a negative input node connected to the reference electrode, and an output node connected to a control electrode of the MOSFET. When the voltage of the reference electrode is within a range, the larger the voltage of the reference electrode is, the less the current of the MOSFET is. Application of this reverse shunt regulator to a flyback converter for output feedback will reduce the power loss in a green mode of the flyback converter. | 06-21-2012 |
20120212981 | POWER CONVERTER WITH ZERO VOLTAGE SWITCHING AND RELATED CONTROL METHOD THEREOF - A power converter includes an output unit, a first transformer, a switch unit, and a processing unit. The first transformer includes a primary winding and a secondary winding. The primary winding is coupled between an input voltage and a first node. The switch unit is coupled between the first node and a second node. The processing unit is coupled between the input voltage and the first node. When the switch unit is in an OFF state, the processing unit is used to receive a first sensing voltage and store a sensing power of the first sensing voltage through a first path, isolate the first sensing voltage from feeding in through a second path different from the first path simultaneously, and then release the stored sensing power through the second path. The first sensing voltage is generated as the switch unit switches from an ON state to the OFF state. | 08-23-2012 |
20120218787 | STABILIZED VOLTAGE POWER SUPPLY - Disclosed is a stabilized voltage power supply comprising an A/D converting circuit configured to convert an alternate current voltage received from an external power supply to an initial direct current voltage; a PWM signal output unit configured to generate and output a PWM signal; a control switch configured to alternatively carry out, based on control of the received PWM signal, switching between a turn-on state and a turn-off state so as to convert the initial direct current voltage to a pulse voltage whose duty ratio is the same with that of the PWM signal; a final converting circuit configured to convert the pulse voltage to a final direct current voltage, and output the final direct current voltage to an external load via an output terminal; and a feed unit configured to feed the final direct current voltage back to the PWM signal output unit. | 08-30-2012 |
20120224400 | ELECTRICAL EQUIPMENT - A television includes a power supply circuit including a transformer that converts input voltage to output voltage, an input voltage monitoring circuit that monitors the input voltage based on a voltage value of a primary side or a secondary side of the transformer, and a control unit that determines whether or not the input voltage exceeds a specified value based on monitoring results of the input voltage monitoring circuit and provides a warning or notification that the input voltage is excessive when it is determined that the input voltage exceeds the specified value. | 09-06-2012 |
20120230064 | SWITCHING CONTROLLER WITH VALLEY-LOCK SWITCHING AND LIMITED MAXIMUM FREQUENCY FOR QUASI-RESONANT POWER CONVERTERS - The present invention provides a controller for a power converter. The controller comprises a PWM circuit, a detection circuit, a signal generator, an oscillation circuit, a valley-lock circuit, a timing circuit and a burst circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to control and disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a waveform obtained from the transformer. The signal generator is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a turning-on signal. The turning-on signal is coupled to enable the switching signal. A maximum frequency of the turning-on signal is limited. | 09-13-2012 |
20120243271 | Power Converter with Reduced Power Dissipation - A power converter with reduced power dissipation at light loads and method of operating the same. In one embodiment, the power converter includes an opto-isolator circuit configured to produce an output signal dependent on an output characteristic of the power converter. The power converter also includes a controller configured to control the output characteristic to a first regulated value when the output signal is greater than or equal to a threshold level, and control the output characteristic to a second regulated value less than the first regulated value when the output signal is less than the threshold level. | 09-27-2012 |
20120243272 | CONSTANT CURRENT POWER SUPPLY APPARATUS - A constant current power supply apparatus is provided which can drive a load with a constant current, even if the circuit configuration is such that a time delay is generated in the feedback control of a converter, or the like. An FB period restricting circuit including an ON generation circuit, OR circuit, inverter, and PMOS restricts the period during which an FB signal is fed back, to the logical sum of the ON period of an SW signal for driving an LED array on and a replenishment period generated by the OR circuit based on the SW signal. An FB signal generation circuit including a differential amplifier, NMOS, reference voltage, capacitor, and shunt regulator generates, in the replenishment period other than the ON period of the SW signal, an FB signal corresponding to an output current having flown through the LED array during the ON period of the SW signal. | 09-27-2012 |
20120250365 | SWITCHING POWER SUPPLY - A switching power supply includes a rectifying unit configured to rectify an input alternating voltage, a storage unit configured to smooth the voltage rectified by the rectifying unit and store as a DC voltage, a pulse signal generation unit configured to generate a pulse signal from the DC voltage stored in the storage unit, and a detection unit configured to detect that a commercial alternating current power supply has been turned off based on the pulse signal generated by the pulse signal generation unit. | 10-04-2012 |
20120250366 | FLYBACK CONVERTER WITH PRIMARY SIDE AND SECONDARY SIDE FEEDBACK CONTROL AND METHOD FOR THE SAME - A flyback converter with primary side and secondary side feedback control includes a transformer, a secondary-side feedback unit and a feedback control unit. The secondary-side feedback unit is electrically connected to a secondary winding of the transformer and comprises an isolated signal transceiver device and an error amplifier. The feedback control unit is electrically connected to an auxiliary winding of the transformer and operatively connected to the isolated signal transceiver device. When the flyback converter is operated in heavy load conditions, the feedback control unit receives a secondary feedback control signal sent from the isolated signal transceiver device for feedback control. When the flyback converter is operated in light load conditions, the feedback control unit receives a primary feedback control signal sensed by the auxiliary winding for feedback control. | 10-04-2012 |
20120257423 | SYSTEMS AND METHODS FOR ADAPTIVE SWITCHING FREQUENCY CONTROL IN SWITCHING-MODE POWER CONVERSION SYSTEMS - Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage and a secondary winding coupled to the primary winding. Additionally, the system includes a compensation component configured to receive the input voltage and generate at least a clock signal based on at least information associated with the input voltage, and a signal generator configured to receive at least the clock signal and generate at least a control signal based on at least information associated with the clock signal. Moreover, the system includes a gate driver configured to receive at least the control signal and generate a drive signal based on at least information associated with the control signal, and a first switch configured to receive the drive signal and affect a first current flowing through the primary winding. | 10-11-2012 |
20120275199 | SWITCH-MODE POWER SUPPLY CONTROLLER AND ASSOCIATED METHOD - One embodiment of the present invention discloses a switch-mode power supply controller and associated method. In an embodiment, the controller comprises an on-time controller, an off-time controller, a switch control signal generator, and a jittering signal generator, wherein the jittering signal generator couples jitter into the on-time or the off-time of a primary switch of the power supply. Therefore the EMI performance may be improved. | 11-01-2012 |
20120281440 | ISOLATED SWITCH-MODE POWER SUPPLY DEVICE - The present invention provides an isolated switch-mode power supply device capable of sufficiently reducing power consumption in a standby mode. An isolated switch-mode power supply device includes: a capacitor that supplies control power for controlling switching of a switching element; a first control unit that includes a constant current supplying unit that controls switching of the switching element; a switching element that connects or disconnects the first control unit and the capacitor; a capacitance element unit having a capacitor to which a constant current is supplied from the constant current supplying unit, a capacitor charge voltage of the capacitance element unit changing according to an outputted voltage in the standby mode; and a second control unit that controls power supply to the first control unit by closing or opening the switching element during a switching pause period in the standby mode according to the capacitor charge voltage of the capacitor. | 11-08-2012 |
20120320639 | METHOD AND APPARATUS TO SELECT A PARAMETER/MODE BASED ON A MEASUREMENT DURING AN INITIALIZATION PERIOD - A power supply includes an energy transfer element coupled between an input and an output. A switch is coupled to an input of the energy transfer element. A threshold detection circuit includes in an integrated circuit coupled to measure a signal from a resistive external circuit coupled between fourth and first external terminals of the integrated circuit during an initialization period after the fourth external terminal has been charged to a supply threshold value. A regulator circuit is coupled between second and fourth external terminals of the integrated circuit. The regulator circuit is coupled to charge the fourth external terminal to the supply threshold value during the initialization period. A selection circuit is coupled to the threshold detection circuit to select a parameter/mode of the integrated circuit in response to the measured signal. | 12-20-2012 |
20130016535 | Controller for a Power Converter and Method of Operating the Same - A control system for a power converter with reduced power dissipation at light loads and method of operating the same. In one embodiment, the control system includes a first controller configured to control a duty cycle of a power switch to regulate an output characteristic of the power converter. The control system also includes a second controller configured to provide a signal in response to a dynamic change of the output characteristic to the first controller to initiate the duty cycle for the power switch. | 01-17-2013 |
20130027988 | SWITCHING CONTROLLER FOR FLYBACK POWER CONVERTERS WITHOUT INPUT CAPACITOR - The present invention proposes a switching controller of a flyback power converter. The switching controller includes a switching circuit, a sample-and-hold circuit, a voltage detection circuit, an oscillation circuit, and a comparator. The voltage detection circuit generates a holding signal when a level of an input voltage of the flyback power converter is lower than a low-threshold. The oscillation circuit limits the maximum frequency of switching signal. The maximum frequency is increased in response to a decrement of a modulation signal. The modulation signal correlated with a level of the input voltage is used to generate a control signal when the level of the input voltage is lower than an ultra-low-threshold. The control signal is enabled to operate the flyback power converter in continuous current mode operation. Therefore, an input capacitor can be eliminated and manufacturing cost is saved. | 01-31-2013 |
20130094253 | Control Circuit for Offline Power Converter without Input Capacitor - The present invention provides a control circuit for a power converter. The control circuit includes a switching circuit, an input-voltage detection circuit and a current-limit threshold. The switching circuit generates a switching signal coupled to switch a transformer of the power converter for regulating an output of the power converter in response to a feedback signal. The input-voltage detection circuit generates a control signal when an input voltage of the power converter is lower than a low-input threshold. The feedback signal is generated in response to the output of the power converter. A maximum duty of the switching signal is increased in response to the control signal. The current-limit threshold is for limiting a maximum value of a switching current flowing through the transformer. The current-limit threshold is increased in response to the control signal. An input of the power converter doesn't connect with electrolytic bulk capacitors. | 04-18-2013 |
20130229833 | FEEDBACK CIRCUIT AND CONTROL METHOD FOR AN ISOLATED POWER CONVERTER - A feedback circuit for an isolated power converter includes an opto-coupler and a reversed polarity regulator. The opto-coupler provides a current related to an output voltage of the isolated power converter. When the isolated power converter enters light load, the output voltage rises and the reversed polarity regulator reduces the current to decrease the power consumption and thus improve the light load efficiency of the isolated power converter. | 09-05-2013 |
20130250627 | POWER CONVERTER WITH REDUCED POWER CONSUMPTION IN STANDBY MODE - In accordance with various embodiments a converter is provided, including: a transformer comprising a primary side and a secondary side; a primary side circuit arrangement coupled to the primary side of the transformer; a secondary side circuit arrangement coupled to the secondary side of the transformer, wherein the secondary side circuit arrangement is configured to provide at least one of an output voltage and an output current; a coupling component configured to provide information about at least one of the output voltage and the output current to the primary side circuit arrangement; a first energy supply configured to provide the coupling component with a first current; and second energy supply configured to provide the coupling component with a second current, wherein the second current is lower than the first current. | 09-26-2013 |
20130286691 | METHOD AND APPARATUS FOR IMPLEMENTING AN UNREGULATED DORMANT MODE IN A POWER CONVERTER - A power converter controller includes a drive signal generator coupled to generate a drive signal to control switching of a power switch to regulate a flow of energy to a power converter output in response to an energy requirement of a load. A voltage supply rail is coupled to supply a voltage to the drive signal generator. The supplied voltage is used by the drive signal generator to generate the drive signal. A control circuit is coupled to generate a power down signal that stops the supply of the voltage to the drive signal generator to stop the generation of the drive signal and the control of the switching of the power switch for a period of time. Timer circuitry determines a duration of the period of time and triggers the control circuit to restart the supply of the voltage by the supply rail to the drive signal generator. | 10-31-2013 |
20130294117 | METHOD AND APPARATUS FOR CONTROLLING THE MAXIMUM OUPUT POWER OF A POWER CONVERTER - An example control circuit for use in a power converter includes an input voltage sensor, a current sensor, and a drive signal generator. The input voltage sensor generates a first signal representative of an input voltage (Vin) of the power converter. The current sensor generates a second signal representative of a switch current through a power switch of the power converter. The drive signal generator generates a drive signal to control switching of the power switch in response to the first and second signals. The drive signal generator sets a switching frequency of the drive signal based on a product K×Vin×t to control a maximum output power of the power converter, where K is a fixed number and t is a time it takes the second signal to change between two values of the switch current when the power switch is in an on state. | 11-07-2013 |
20130301312 | ISOLATED SWITCHING POWER SUPPLY APPARATUS - An isolated switching power supply apparatus includes a transformer, a primary-side circuit that includes at least a switching element and supplies input power from an input terminal to a primary winding by controlling on/off of the switching element, and a secondary-side circuit that is electrically isolated from the primary-side circuit and that outputs output power resulting from power conversion performed by the transformer from a secondary winding to an output terminal. The apparatus includes a first circuit board to which the primary winding is connected and that includes the primary-side circuit and the input terminal, and a second circuit board to which the secondary winding is connected and that includes the secondary-side circuit and the output terminal. The first and second circuit boards are stacked in a multilayer manner. The primary and secondary windings are arranged around a core that extends through the first and second circuit boards. | 11-14-2013 |
20130308349 | SWITCHING REGULATOR, THE CONTROL CIRCUIT AND THE METHOD THEREOF - A switching regulator that decreases power loss and resolves thermal issues by jumping its switching frequency to a maximum frequency when its load reaches a peak load. | 11-21-2013 |
20130329468 | SWITCHING CONTROLLER WITH CLAMP CIRCUIT FOR CAPACITOR-LESS POWER SUPPLIES - A control circuit of a power converter according to the present invention comprises a switching circuit and a sample circuit. The switching circuit generates a switching signal in accordance with a feedback signal and a sampled signal. The switching signal is coupled to switch a transformer of the power converter for regulating an output of the power converter. The feedback signal is generated in accordance with the output of the power converter. The sample circuit generates the sampled signal by sampling a signal of the transformer. The sampled signal is correlated to an output voltage of the power converter. | 12-12-2013 |
20140016373 | CONTROL CIRCUIT FOR A SWITCHED-MODE POWER SUPPLY - A control circuit for a switched-mode power supply having an input side ( | 01-16-2014 |
20140016374 | REGULATION CIRCUIT HAVING OUTPUT CABLE COMPENSATION FOR POWER CONVERTERS AND METHOD THEREOF - A regulation circuit with the output cable compensation is developed for a power converter. It includes an error amplifier for generating a feedback signal in accordance with an output of the power converter. A compensation circuit is coupled to a transformer of the power converter for generating a compensation signal in response to a transformer signal generated by the transformer. The feedback signal is applied to generate a switching signal for switching the transformer and regulating the output of the power converter. The compensation signal is coupled to modulate the feedback signal for compensating a voltage drop of the output cable of the power converter. | 01-16-2014 |
20140043867 | SWITCHING POWER SUPPLY DEVICE CONTROL CIRCUIT AND SWITCHING POWER SUPPLY - A switching power supply device control circuit and switching power supply can combat fluctuation due to the input voltage in the peak current of a switching element, even when using an oscillator. A control IC is connected to a switching element and to a current detecting resistor, and controls the switching element, the control IC being configured of an OCP comparator that detects an overcurrent with respect to a load, an overcurrent level setting circuit that corrects a fluctuation occurring in the peak current of the switching element in response to the output voltage from the AC input, an oscillator having a frequency modulating function whereby the switching frequency with respect to the switching element can be modulated, and a slope compensation circuit that generates a slope compensation signal increasing monotonically in proportion to the time from the start of each cycle of an oscillating signal of the oscillator. | 02-13-2014 |
20140063866 | METHOD AND APPARATUS FOR A CONTROL CIRCUIT RESPONSIVE TO AN IMPEDANCE COUPLED TO A CONTROL CIRCUIT TERMINAL - A controller includes a current sense circuit and a voltage regulation circuit. The current sense circuit generates a first signal that indicates whether a current through a sense terminal exceeds a first threshold current level, which indicates a fault condition of a power converter. The voltage regulation circuit regulates the sense terminal to a first voltage level when the current through the terminal is less than the first threshold current level and regulates the sense terminal to a second voltage level when the current exceeds the first threshold current level. The current sense circuit generates a second signal that indicates whether the current through the sense terminal exceeds a second threshold current level while the sense terminal is regulated to the second voltage level. The response circuit generates an output signal that determines a response of the controller to the fault condition based on the second signal. | 03-06-2014 |
20140078789 | SWITCHING POWER CONVERTER WITH SECONDARY-SIDE DYNAMIC LOAD DETECTION AND PRIMARY-SIDE FEEDBACK AND CONTROL - A power converter includes a transformer with a primary and a secondary winding. Feedback and control is maintained on the primary-side while a separate load detection circuit detects dynamic load conditions on the secondary-side. The load detection circuit detects dynamic load conditions at the time when a load is connected to the output of the switching power converter and, in turn, generates an alert signal. A coupling circuit coupled to the load detection circuit at the secondary winding side of the transformer and to the controller at the primary winding side of the transformer transmits the alert signal to the controller. The controller regulates the output voltage based on the feedback signal generated at the primary side of the transformer while detecting and responding to the dynamic load condition based on the alert signal generated at the secondary side of the transformer. | 03-20-2014 |
20140085942 | SHUNT REGULATOR HAVING PROTECTION FUNCTION AND POWER SUPPLY DEVICE HAVING THE SAME - There are provided a shunt regulator having a protection function to detect an abnormal state, and a power supply device having the same. The shunt regulator of a power supply device in which a primary side and a secondary side have grounds having different electrical characteristics and are electrically insulated from one another, and power switched from the primary side is induced to the secondary side so as to be output, includes: a comparator positioned on the secondary side and comparing a voltage output from the power supply device with a preset reference voltage; and a first switch performing a control to stop supply of driving power required for a power switching operation of the primary side according to a comparison result from the comparator. | 03-27-2014 |
20140098578 | SWITCHED MODE POWER SUPPLIES - An example embodiment relates to a switched-mode power supply comprising a transformer with a first winding and a second winding. There is a transmitter configured to: detect a detectable variable (Vout) at the first winding, generate a transformer relayed signal in accordance with the detectable variable (Vout), and provide the transformer relayed signal to the first winding. A receiver is configured to: receive the transformer relayed signal from the second winding, and control a controllable variable at the second winding in response to the transformer relayed signal, wherein the transformer relayed signal is a symbol stream comprising a plurality of symbols. | 04-10-2014 |
20140119066 | POWER CONVERTER WITH PRIMARY-SIDE FEEDBACK CONTROL AND VOLTAGE CONTROL METHOD THEREOF - A voltage control method for a power converter includes: acquiring a current of a first primary side winding of a transformer circuit of the power converter; integrating the acquired current to obtain an average voltage; comparing the average voltage with a reflected voltage associated with a current of a secondary side winding of the transformer circuit; and adjusting a duty cycle of a switch of the power converter based on an obtained comparison result for adjustment of an output voltage of the power converter. | 05-01-2014 |
20140126248 | SYSTEMS AND METHODS FOR PROTECTING POWER CONVERSION SYSTEMS UNDER OPEN AND/OR SHORT CIRCUIT CONDITIONS - System and method are provided for protecting a power converter. The system includes a first comparator, and an off-time component. The first comparator is configured to receive a sensing signal and a first threshold signal and generate a first comparison signal based on at least information associated with the sensing signal and the first threshold signal, the power converter being associated with a switching frequency and further including a switch configured to affect the primary current. The off-time component is configured to receive the first comparison signal and generate an off-time signal based on at least information associated with the first comparison signal. The off-time component is further configured to, if the first comparison signal indicates the sensing signal to be larger than the first threshold signal in magnitude, generate the off-time signal to keep the switch to be turned off for at least a predetermined period of time. | 05-08-2014 |
20140133193 | METHODS FOR FLYBACK CONVERTER - Methods for flyback converters are provided. The method, adopted by a flyback converter circuit including a transformer, including: determining an output voltage output from a secondary circuit of the transformer; feeding a feedback voltage based on the output voltage from the secondary circuit back to a primary circuit of the transformer; increasing a current limit and a switching frequency of a primary current with the feedback voltage; and supplying the primary current to a primary winding of the transformer. | 05-15-2014 |
20140140107 | ISOLATED POWER CONVERTER, INVERTING TYPE SHUNT REGULATOR, AND OPERATING METHOD THEREOF - An isolated power converter, an inverting type shunt regulator, and an operating method thereof are disclosed. The isolated power converter includes a transformer, an inverting type shunt regulator, a controller, and an optocoupler. The inverting type shunt regulator is located on the secondary side of the transformer. The inverting type shunt regulator includes an error amplifier and a MOSFET. The controller is located on the primary side of the transformer. The controller includes an inverting unit cooperated with the MOSFET. The controller receives a feedback voltage. The optocoupler is coupled to the inverting type shunt regulator and the controller to provide an opto-coupling current to the controller. | 05-22-2014 |
20140140108 | CONTROLLER FOR GENERATING JITTERS IN A CONSTANT CURRENT MODE OF A POWER CONVERTER AND METHOD THEREOF - A controller for generating jitters in a constant current mode of a power converter includes a current pin, an auxiliary pin, a constant current control unit, and a control signal generation unit. The current pin is used for receiving a primary side voltage determined according to a resistor and a primary side current flowing through the power converter. The auxiliary pin is used for receiving a voltage corresponding to an auxiliary winding of the power converter. The constant current control unit is used for generating an adjustment signal according to the primary side voltage, a discharge time corresponding to the voltage, and a reference voltage. The reference voltage has a predetermined range jitter voltage. The control signal generation unit is used for adjusting a period of a gate control signal according to the adjustment signal. | 05-22-2014 |
20140192566 | PRIMARY-SIDE CONTROLLED PROGRAMMABLE POWER CONVERTER - A circuit for controlling a programmable power converter is provided. The circuit comprises a control circuit, a switching controller, and a first opto-coupler. The control circuit generates a programmable voltage-reference signal for regulating an output voltage of the programmable power converter. A feedback circuit of the control circuit detects the output voltage for generating a feedback signal in response to the programmable voltage-reference signal and the output voltage. The switching controller detects a switching current of a transformer for generating a switching signal coupled to switch the transformer for generating the output voltage and an output current in response to the feedback signal and the switching current of the transformer. The first opto-coupler transfers the feedback signal from the control circuit to the switching controller. The control circuit is at the secondary side of the transformer and the switching controller is at the primary side of the transformer. | 07-10-2014 |
20140254211 | SYSTEM AND METHOD FOR INFORMATION COMMUNICATION BETWEEN ELECTRICALLY ISOLATED CIRCUITS - An exemplary power conversion system includes a power converter and a protection circuit coupled with the power converter. The power converter is configured to convert an input power into an output power. The power converter includes an isolator magnetically coupling a primary side and a secondary side and at least one primary switch coupled in series with the primary side. The at least one primary switch is configured to turn on or turn off current to the isolator on the primary side. The protection circuit is coupled to the at least one primary switch. The protection circuit includes a detecting device for detecting switch state of a secondary switch on the secondary side. The detecting device is configured to drive the at least one primary switch according to the detected switch state. A method for operating the power conversion system is also described. | 09-11-2014 |
20140254212 | POWER CONVERTER USING MULTIPLE CONTROLLERS - A power converter controller includes a primary controller and a secondary controller. The primary controller is coupled to receive one or more request signals from the secondary controller and transition a power switch from an OFF state to an ON state in response to each of the received request signals. The primary controller is coupled to detect a turn-off condition when the power switch is in the ON state and transition the power switch from the ON state to the OFF state in response to detection of the turn-off condition. The secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to transmit the request signals to the primary controller and control the amount of time between the transmission of each of the request signals. | 09-11-2014 |
20140254213 | POWER CONVERTER OUTPUT VOLTAGE CLAMP AND SUPPLY TERMINAL - A secondary control circuit includes a voltage regulator circuit to be coupled to an output of a power converter to provide a regulated power supply. One or more switched loads is coupled between a first terminal to be coupled to the output of the power converter and an output ground terminal. One or more comparator circuits is coupled to a second terminal coupled to receive an output sense signal. Each one of the one or more comparator circuits is coupled to receive a respective one of one or more reference signals. Each respective one of the one or more reference signals is a scaled representation of a first one of the one or more reference signals. Each one of the one or more switched loads is coupled to be switched in response to an output of a respective one of the one or more comparator circuits. | 09-11-2014 |
20140254214 | TECHNIQUES FOR CONTROLLING A POWER CONVERTER USING MULTIPLE CONTROLLERS - A power converter controller includes a primary controller that is galvanically isolated from a secondary controller. The primary controller controls a state of a power switch during a first mode of operation according to a switching pattern defined by the primary controller. During a second mode of operation, the primary controller controls the state of the power switch in response to control signals received via a communication link. The secondary controller operates in a powered down state during the first mode of operation. The secondary controller initiates a transition operation with the primary controller that transitions the primary controller and the secondary controller from the first mode of operation to the second mode of operation. In the second mode of operation, the secondary controller transmit the control signals to the primary controller via the communication link. | 09-11-2014 |
20140254215 | CONTROLLER FOR A POWER CONVERTER AND METHOD OF OPERATING THE SAME - A control system for a power converter with reduced power dissipation and method of operating the same. In one embodiment, the control system includes a first controller coupled to a primary winding of a transformer and configured to control a duty cycle of a power switch to regulate an output characteristic of the power converter. The control system also includes a second controller configured to provide a signal to one of a secondary winding of the transformer and a circuit element spanning an isolation boundary of the transformer in response to a dynamic change of the output characteristic to trigger the first controller to initiate the duty cycle for the power switch. | 09-11-2014 |
20140268917 | ISOLATED ERROR AMPLIFIER FOR ISOLATED POWER SUPPLIES - A power converter may include an amplifier that generates an error signal, a modulator that generates a modulated error signal, an isolator that generates an isolated modulated error signal, and a demodulator that generates an isolated error signal, which may be substantially proportional to the difference between the output signal and the reference signal, and a controller that controls a power stage to generate the output signal of the power converter. | 09-18-2014 |
20140268918 | LED Power Supply - A method can be used for controlling the switching operation of a switching power converter that includes a semiconductor switch coupled in series to an inductor. The switching power converter consumes an input current from a power supply and provides an output current to a load. In each switching cycle a switch-on time instant is detected for the semiconductor switch. The semiconductor switch is closed thus enabling, at the detected switch-on time instant, the input current passing through the semiconductor switch. The semiconductor switch is opened after a desired on-time, during which the input current rises from zero to a peak value, has passed. A time interval is detected, in which the instantaneous output current is not zero. A first value that represents the peak of the input current is obtained during the on-time. | 09-18-2014 |
20140268919 | SWITCHING POWER CONVERTER WITH SECONDARY TO PRIMARY MESSAGING - A primary-only power supply enables transmission of a signal or message from the secondary side of an isolated power supply to the primary side. To enable robust detection of the message without interfering with primary side sensing for output regulation, a configurable impedance current path is configured between the primary winding and ground. The primary side controller controls the configurable impedance current path to have a relatively low impedance during the normal mode and a relatively high impedance during the messaging mode. | 09-18-2014 |
20140268920 | Systems and Methods for Flyback Power Converters with Switching Frequency and Peak Current Adjustments - System and method for regulating a power converter. The system includes a comparator configured to receive a first signal and a second signal and generate a comparison signal based on at least information associated with the first signal and the second signal. The first signal is associated with at least an output current of a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive at least the comparison signal and generate a modulation signal based on at least information associated with the comparison signal, and a driver component configured to receive the modulation signal and output a drive signal to a switch to adjust a primary current flowing through a primary winding of the power converter. The modulation signal is associated with a modulation frequency corresponding to a modulation period. | 09-18-2014 |
20140301116 | Switched Mode Power Supply Including a Flyback Converter with Primary Side Control - A method and apparatus for controlling a flyback converter are presented. The flyback converter includes a transformer, a semiconductor switch coupled to a primary winding of the transformer, a current measurement circuit coupled to the semiconductor switch, a diode coupled in series to a secondary winding of the transformer, and a controller. The controller is configured to receive a feedback voltage, a reference signal, and the measured primary current and generate a control signal for the semiconductor switch dependent on the feedback voltage, the reference signal, and the measured primary current. The semiconductor switch switches on and off cyclically in CCM operation. | 10-09-2014 |
20140301117 | POWER SUPPLY APPARATUS AND IMAGE FORMING APPARATUS - The power supply apparatus includes a transformer having a primary side and a secondary side insulated from each other, a switch element for switching current flowing in the primary side of the transformer, a control part configured to control an operation of the switch element, and two feedback parts configured to detect an output voltage from the transformer so as to output, to the control part, a detection signal in accordance with the output voltage for feedback to the primary side of the transformer. | 10-09-2014 |
20140313792 | POWER DELIVERY DEVICE, AC ADAPTER, AND ELECTRONIC APPARATUS - The PD device comprises a primary-side controller configured to control an input current of a DC/DC converter disposed between an input and an output, and a secondary-side controller connected with AC coupling to the output, and configured to feedback electric power information of the output to the primary-side controller. The primary-side controller varies an output voltage value and an available output current capacity of the DC/DC converter by controlling the input current on the basis of the electric power information fed back from the secondary-side controller. The primary-side controller can change an overpower detecting set value in accordance with the target equipments connected to the output, thereby executing the power change of the DC/DC converter. | 10-23-2014 |
20140313793 | POWER DELIVERY DEVICE, AC ADAPTER, ELECTRONIC APPARATUS AND POWER DELIVERY SYSTEM - The PD device includes: a DC/DC converter disposed between an input and an output; a primary-side controller configured to control an input current of the DC/DC converter; and a secondary-side controller connected with AC coupling to the output, and configured to feed back electric power information of the output to the primary-side controller. The primary-side controller varies an output voltage value and an available output current capacity of the DC/DC converter by controlling the input current on the basis of the electric power information fed back from the secondary-side controller. | 10-23-2014 |
20140313794 | POWER DELIVERY DEVICE AND START-UP METHOD, AC ADAPTER AND ELECTRONIC APPARATUS - The PD device includes: a DC/DC converter disposed between an input and an output; a primary-side controller configured to start up the DC/DC converter; and a secondary-side controller connected to an output of the DC/DC converter, the secondary-side controller AC-coupled to the output, the secondary-side controller configured to feed back electric power information of the output to the primary-side controller and an input of the DC/DC converter, wherein the secondary-side controller controls an input current of the DC/DC converter, thereby varying an output voltage value and an available output current capacity of the DC/DC converter. | 10-23-2014 |
20140376279 | POWER ESTIMATION DEVICE USING COAXIAL WINDING TRANSFORMER - Disclosed is a power estimation device using a coaxial winding transformer which includes: a switching control unit that generates primary current by performing switching control on power source; a coaxial winding transformer that includes a core, and a primary winding, a secondary winding, and an auxiliary winding which are wound on the core and outputs secondary current in accordance with the winding ratio of the secondary winding to the primary winding by receiving the primary current; and a power estimation unit that estimates power outputted to the secondary winding by sensing output of the auxiliary winding in accordance with the winding ratio of the auxiliary winding to the primary winding, in which the coaxial winding transformer is formed by winding a cable, which uses at least inner conductor as the secondary winding and uses one outer conductor surrounding the inner conductor as the auxiliary winding, around the core. | 12-25-2014 |
20150078040 | ISOLATED SWITCHING POWER SUPPLY - An isolated switching power supply can include a switching element connected to an input power supply, a control circuit that ON/OFF-drives the switching element and generates an AC power in a secondary winding and in an auxiliary winding of the isolation transformer, an output circuit that rectifies the AC power generated in the on a secondary winding of the isolation transformer and outputs the rectified power, an internal power supply circuit that generates a driving power supply voltage for the control circuit from the AC power generated in the auxiliary winding, an output voltage detecting circuit that feeds back an output monitoring voltage obtained from the driving power supply voltage to the control circuit to control the ON/OFF driving of the switching element by the control circuit and an output voltage controller that changes a level of the output monitoring voltage obtained from the driving power supply voltage. | 03-19-2015 |
20150349651 | SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal. | 12-03-2015 |
20150357925 | CONTROLLER FOR ELIMINATING ACOUSTIC NOISE OF A POWER CONVERTER AND RELATED METHOD THEREOF - A controller for eliminating acoustic noise of a power converter includes a control unit and a gate signal generation unit. The control unit is used for detecting a frequency corresponding to a gate control signal in a burst mode of the power converter. When the frequency is greater than a predetermined frequency, the control unit increases a resistance of a compensation resistor coupled to a compensation pin of the power converter; and when the frequency is less than the predetermined frequency, the control unit decreases the resistance of the compensation resistor. The gate signal generation unit is coupled to the control unit for generating the gate control signal to a power switch of a primary side of the power converter according to the resistance of the compensation resistor. The power switch is turned on according to the gate control signal. | 12-10-2015 |
20150372603 | FLYBACK POWER SUPPLY CIRCUIT WITH PROGRAMMABLE FUNCTION AND CONTROL METHOD THEREOF - The present invention discloses a flyback power supply circuit with a programmable function and a control method thereof. The flyback power supply circuit includes: a transformer circuit, a power switch circuit, a primary side control circuit, an opto-coupler circuit, and a secondary side control circuit. The primary side control circuit determines whether an over voltage condition occurs, and further determines whether to generate an over voltage protection signal to turn OFF a power switch of the power switch circuit according to a rate of increase of a feedback signal and a control level, or according to the rate of increase of the feedback signal and a rate of change of a target control signal. | 12-24-2015 |
20150372604 | TECHNIQUES FOR CONTROLLING A POWER CONVERTER USING MULTIPLE CONTROLLERS - A power converter controller includes a primary controller coupled to operate in a first mode to control a power switch with a primary switching pattern. A secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to initiate a transition operation with the primary controller to take control of the power switch with one or more control signals through a communication link. The primary controller is coupled to acknowledge receipt of the one or more control signals to the secondary controller and transition from the first mode to a second mode. | 12-24-2015 |
20150381056 | SWITCHED-MODE POWER SUPPLY DEVICE - A switched-mode power supply device is disclosed comprising an AC power supply, a transformer comprising a primary winding and a secondary winding, a switching element electrically connected to the primary winding, a secondary-side rectifying and smoothing circuit that generates an output voltage by rectifying and smoothing the pulse voltage, a load ratio detection circuit that detects if a load ratio is not greater than a load ratio threshold value during steady load, and outputs a drive switch signal based on the detection, and a drive circuit that, on the basis of the drive switch signal, causes the switching element to perform switching operation in one of a normal drive in which a speed of charging agate voltage is faster and a soft drive in which the speed of charging the gate voltage is slower. | 12-31-2015 |
20150381058 | SWITCHING POWER SOURCE, METHOD AND CONTROL CHIP FOR CONTROLLING THE SAME - A switching power source, a method and a control chip for controlling the same are provided. The switching power source includes: a filtering and rectifying module, connected with an AC power source and configured to filter and rectify an alternating current outputted from the AC power source to obtain a direct current; a control module, connected with the filtering and rectifying module and configured to obtain an amplitude of the alternating current from the direct current, to adjust a frequency of a control signal according to the amplitude, in which the control module decreases the frequency of the control signal continuously or intermittently when the amplitude increases, and to output the control signal, and a primary constant current circuit, connected with the control module and the filtering and rectifying module respectively, and configured to receive the control signal and to output a constant current according to the control signal. | 12-31-2015 |
20160013723 | POWER CONVERTER USING MULTIPLE CONTROLLERS | 01-14-2016 |
20160028318 | SYSTEMS AND METHODS FOR CONSTANT VOLTAGE CONTROL AND CONSTANT CURRENT CONTROL - System and method for regulating a power conversion system. A system controller for regulating a power conversion system includes a first controller terminal, a second controller terminal and a third controller terminal. The system controller is configured to receive an input signal at the first controller terminal and turn on or off a switch based on at least information associated with the input signal to adjust a primary current flowing through a primary winding of the power conversion system, receive a first signal at the second controller terminal from the switch, and charge a capacitor through the third controller terminal in response to the first signal. | 01-28-2016 |
20160087540 | SYSTEM FOR INFORMATION FEEDBACK THROUGH ISOLATION IN POWER CONVERTERS - An information feedback system is disclosed. The information feedback system comprises a separating device having the primary winding and the secondary winding, a first electrical switch and a controller. The secondary winding is coupled to an operation device through the first electrical switch. The first electrical switch and the operation device are coupled to the controller. The energy is discharged from the secondary winding to the operation device through the first electrical switch. The operation device receives the energy from the first electrical switch to generate a plurality of commands. The controller receives the commands and uses the first electrical switch to encode a plurality of signals to generate encoded information according to the commands. The separating device transmits the encoded information from the secondary winding to the primary winding. | 03-24-2016 |
20160105117 | ISOLATED POWER CONTROL DEVICE, POWER CONVERSION DEVICE AND ISOLATED POWER CONTROL METHOD USED IN POWER CONVERSION DEVICE - An isolated power control device that includes an auxiliary isolated power circuit and a voltage level identification unit is provided. The auxiliary isolated power circuit includes a transformer module, a control module, and a switch module. The transformer module includes a primary side and a secondary side. The control module generates a switch control signal according to a primary side remote on/off control signal. The switch module is conducted according to the switch control signal to transmit an input auxiliary power signal to the primary side of the transformer module such that the auxiliary isolated power circuit generates a target voltage signal having a plurality of voltage levels. The voltage level identification unit receives the target voltage signal to output a secondary side remote on-off control signal to control a main isolated power device. | 04-14-2016 |
20160111963 | SWITCHING CONVERTER AND CONTROL CIRCUIT THEREOF, CURRENT SENSING METHOD, AC/DC CONVERTER, AND POWER ADAPTOR AND ELECTRONIC DEVICES - A control circuit is used in a switching converter including at least, a switching transistor and a coil connected to the switching transistor. The control circuit includes: a current comparing circuit that asserts a peak current sensing signal when a current flowing in the coil during the ON period of the switching transistor reaches a threshold current. The current comparing circuit includes: a first comparator that compares a sensed voltage according to the current flowing in the switching transistor and the coil with a threshold voltage defining the threshold current, and generates a comparison signal; and a variable delay circuit that generates the peak current sensing signal by delaying the comparison signal, a delay amount of the variable delay circuit varying according to a period of time from a turn-on of the switching transistor to a transition of the comparison signal. | 04-21-2016 |
20160141966 | FLYBACK POWER CONVERTER, SECONDARY SIDE CONTROL CIRCUIT, AND CONTROL METHOD THEREOF - The present invention provides a flyback power converter, a secondary side control circuit, and a control method thereof. The flyback power converter converts an input voltage to an output voltage, and provides a load current to a load circuit. The flyback power converter includes: a transformer circuit, a power switch circuit, a switch current sense circuit, a primary side control circuit, and a secondary side control circuit. The secondary side control circuit adaptively adjusts a frequency of a zero of a compensator gain function and/or a mid-frequency gain of the compensator gain function according to the load current, such that a number of poles of a system open loop gain function of the flyback power converter is at most more than a number of zeroes of the system open loop gain function by one under a crossover frequency. | 05-19-2016 |
20160149480 | POWER SUPPLY WITH LOW VOLTAGE PROTECTION AND METHOD OF OPERATING THE SAME - A power supply with low voltage protection provides an output voltage. The power supply includes a driving switch and a control unit. The control unit generates a control signal with a duty cycle. The driving switch receives the control signal to drive the output voltage of the power supply. The control unit enables an under-voltage protection mode when the control unit detects that the output voltage is less than a threshold output voltage value and the duty cycle is less than a maximum duty cycle value. The control unit disables the under-voltage protection mode when the control unit detects that the output voltage is less than the threshold output voltage value and the duty cycle reaches to the maximum duty cycle value. | 05-26-2016 |
20160172986 | SWITCHED-MODE POWER SUPPLY DEVICE | 06-16-2016 |
20160181931 | SWITCHING POWER SUPPLY AND METHOD FOR CONTROLLING VOLTAGE OF BULK CAPACITOR IN THE SAME | 06-23-2016 |
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