SYSTEM GENERAL CORPORATION Patent applications |
Patent application number | Title | Published |
20150062972 | SYNCHRONOUS RECTIFIER CONTROL CIRCUITS OF POWER CONVERTERS - A synchronous rectifying control circuit of a power converter is provided. The synchronous rectifying control circuit comprises a synchronous rectifying driver, a charge pump capacitor, and a capacitor. The synchronous rectifying driver is coupled to a transformer for generating a control signal to switch a transistor. The charge pump capacitor is coupled to a power source for generating a charge pump voltage. The capacitor is coupled to store the charge pump voltage. The transistor is coupled to the transformer and operated as a synchronous rectifier. The charge pump voltage is coupled to guarantee a sufficient driving capability for the control signal. | 03-05-2015 |
20140289540 | PROGRAMMABLE POWER SUPPLY - The present invention provides a method of programming a programmable power supply. In the method, a requesting signal is generated in a device, and the requesting signal is received in the programmable power supply. Then, an output voltage of the programmable power supply is determined in accordance with a frequency of the requesting signal. The output voltage of the programmable power supply is coupled to power a load of the device. A de-bounce operation is further provided for filtering noises of the requesting signal. The requesting signal comprises a high-state period and a low-state period. The high-state period is defined during which a level of the requesting signal is higher than a threshold. The low-state period is defined during which the level of the requesting signal is lower than the threshold. The output voltage of the programmable power supply is further determined by a period of the requesting signal. | 09-25-2014 |
20140239885 | CONTROL CIRCUIT FOR CHARGING BATTERY THROUGH PROGRAMMABLE POWER SUPPLIER - A charging circuit for charging a battery is provided. A power supplier has a communication interface coupled to a cable for receiving command-data and generates a DC voltage and a DC current in accordance with the command-data. A controller is coupled to the battery for detecting a battery-voltage and generates the command-data in accordance with the battery-voltage. A switch is coupled to the cable for receiving the DC voltage and the DC current through a connector. The DC voltage and the DC current generated by the power supply are coupled to the cable, and the DC voltage and the DC current are programmable in accordance with the command-data. The command-data generated by the controller is coupled the cable through a communication circuit of the controller. The controller is coupled the connector for detecting a connector-voltage and control an on/off state of the switch in response to the connector-voltage. | 08-28-2014 |
20140239882 | APPARATUS FOR CHARGING BATTERY THROUGH PROGRAMMABLE POWER ADAPTER - An apparatus for charging a battery is provided and includes a power adaptor and a controller. The power adaptor has a communication interface coupled to a cable of the power adapter for receiving command-data and generates a DC voltage and a DC current according to the command-data. The controller is coupled to the battery for detecting a battery voltage of the battery and generates the command-data according to the battery voltage. The DC voltage and the DC current are coupled to the cable and programmable according to the command-data. The command-data is coupled the cable through a communication circuit of the controller. | 08-28-2014 |
20140211519 | SINGLE-STAGE PFC CONVERTER WITH CONSTANT VOLTAGE AND CONSTANT CURRENT - An exemplary embodiment of a switching controller for a power converter is provided. The switching controller for a power converter comprises: a power device, an input circuit and a compensation capacitor. The power device is coupled to switch a transformer of the power converter for regulating an output voltage and an output current of the power converter. The input circuit is coupled to the transformer to sample an input signal which is correlated to the output voltage of the power converter to obtain a feedback signal. The feedback signal is utilized to generate a switching signal for controlling the power device. The switching signal is modulated to operate the power converter in boundary current mode (BCM) or discontinuous current mode (DCM). | 07-31-2014 |
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 |
20140185333 | ACTIVE CLAMP CIRCUITS FOR FLYBACK POWER CONVERTERS - An active clamp circuit for a flyback power converter is provided. The active clamp circuit includes a power transistor, a capacitor, a high-side transistor driver, a charge-pump circuit, and a controller. The power transistor is coupled in series with a capacitor to develop an active-clamper. The active-damper is coupled in parallel with a primary winding of a transformer of the flyback power converter. The high-side transistor driver is coupled to drive the power transistor. The charge-pump circuit is coupled to a voltage source and the high-side transistor driver to provide a power supply to the high-side transistor driver. The controller generates a control signal coupled to control the high-side transistor driver. The control signal is generated in response to a demagnetizing time of the transformer. | 07-03-2014 |
20140176095 | METHOD AND APPARATUS FOR CONTROLLING PROGRAMMABLE POWER CONVERTER - The present invention provides a circuit for controlling a programmable power converter. The circuit includes a micro-controller, a controller, and a timer. The controller includes a voltage error amplifier. The micro-controller has a program memory and a data memory. The controller generates switching signals in response to a voltage-feedback signal for regulating an output voltage of the programmable power converter. The voltage error amplifier generates the voltage-feedback signal according to a voltage reference signal and the output voltage of the programmable power converter. A gain of the voltage error amplifier and a value of the reference signal are programmed by the micro-controller. | 06-26-2014 |
20140118039 | CHARGE PUMP CIRCUITS HAVING FREQUENCY SYNCHRONIZATION WITH SWITCHING FREQUENCY OF POWER CONVERTERS - A control circuit of a power converter is provided. The control circuit includes a switching circuit and a charge pump circuit. The switching circuit generates a switching signal for controlling the power converter. The charge pump circuit includes an oscillator for generating an oscillation signal synchronized with the switching signal. The oscillation signal is coupled to control a switch of the charge pump circuit for generating a voltage source. | 05-01-2014 |
20140001992 | Control Circuit with Frequency Hopping for Permanent Magnet Motor Control | 01-02-2014 |
20130301324 | ELECTRO-MAGNETIC INTERFERENCE REDUCTION CIRCUIT FOR POWER CONVERTERS AND METHOD THEREOF - The present invention provides a circuit of reducing electro-magnetic interference for a power converter. The circuit includes an oscillator, a switching voltage divider, and a sample-and-hold circuit. The oscillator has a terminal for receiving a modulation voltage. The modulation voltage is correlated with an input voltage obtained from an input of the power converter. The switching voltage divider is enabled and disabled by a switch to attenuate the input voltage into a sampled voltage in response to a sampling signal. The sample-and-hold circuit receives the sampled voltage to generate the modulation voltage. A switch of the sample-and-hold circuit controlled by a holding signal conducts the sampled voltage to a capacitor of the sample-and-hold circuit to generate the modulation voltage across the capacitor. | 11-14-2013 |
20130250639 | DIGITAL CONTROLLED POWER CONVERTER WITH EMBEDDED MICROCONTROLLER - The present invention provides a digital controller for a power converter. The digital controller includes a microcontroller, an analog-to-digital converter, a signal generator, a protection circuit, and a PWM circuit. The analog-to-digital converter is coupled to an output of the power converter for generating a digital feedback signal for the microcontroller. The signal generator is controlled by the microcontroller for generating a switching signal coupled to switch a transformer. The protection circuit generates a reset signal to disable the switching signal. The microcontroller controls the switching signal to regulate the output of the power converter. The protection circuit is further coupled to detect a switching current of the transformer for controlling the reset signal if the switching current of the transformer exceeds a second threshold. The PWM circuit generates a PWM signal coupled to control a synchronous rectifying transistor for synchronous rectifying operation. | 09-26-2013 |
20130241509 | CONTROLLER WITH POWER SAVING FOR POWER CONVERTERS AND METHOD FOR THE SAME - The present invention proposes a controller with power saving for a power converter. The controller includes a delay circuit, a detection circuit, an output circuit, a counter circuit, a wake-up circuit and a PWM circuit. The delay circuit determines a delay time. The detection circuit activates the delay circuit whenever an output load of the power converter is lower than a light-load threshold. The output circuit generates a power-saving signal to cease a regulation of the power converter after the delay time ends. The regulation of the power converter is resumed once the output load increases during the regulation of the power converter is being ceased. The counter circuit coupled to the delay circuit is counted by the delay circuit to determine a sleep period. The output circuit generates the power-saving signal to cease the regulation of the power converter after the sleep period ends. | 09-19-2013 |
20130223111 | DIGITAL CONTROL CIRCUIT FOR RESONANT POWER CONVERTERS - A resonant control circuit for a power converter is provided. The resonant control circuit includes a microcontroller, a switching-signal timer, a first PWM timer, and a signal detection circuit. The microcontroller has a memory circuit, and the memory circuit includes a program memory and a data memory. The switching-signal timer generates a first switching signal coupled to switch a transformer. The first PWM timer generates a PWM signal coupled to control a synchronous rectifying transistor of the power converter for synchronous rectifying. The signal detection circuit is coupled to an output of the power converter for generating a feedback data from a feedback signal. The microcontroller controls the first switching signal by programming the switching-signal timer in accordance with the feedback data. The microcontroller controls the first PWM signal by programming the first PWM timer in response to the first switching signal. | 08-29-2013 |
20130182469 | ELECTRO-MAGNETIC INTERFERENCE REDUCTION CIRCUIT FOR POWER CONVERTERS AND METHOD FOR THE SAME - The present invention provides a circuit of reducing electro-magnetic interference for a power converter. The circuit includes an oscillator, a current generation circuit, a feedback circuit and a ramping generator. The oscillator has a first terminal for receiving a first jittering current and a second terminal for feeding a second jittering current. The first jittering current and the second jittering current are correlated with a line signal obtained from an input of the power converter to vary a frequency of the oscillator. The first jittering current and the second jittering current are unequal. As the first jittering current is set greater than the second jittering current, the frequency of the switching signal increases whenever the line signal is increasing. As the first jittering current is set lower than the second jittering current, the frequency of the switching signal decreases whenever the line signal is increasing. | 07-18-2013 |
20130147452 | SWITCHING CURRENT SYNTHESIS CIRCUIT FOR POWER CONVERTER - A control circuit of a power converter is provided. The control circuit comprises a PWM circuit, a sample circuit, and emulation circuit. The PWM circuit generates a switching signal for switching an inductor and generating a switching current of the inductor in response to a current feedback signal. The sample circuit is coupled to sample a switching current signal into a capacitor during an on time of the switching signal. The emulation circuit generates a discharge current couple to discharge the capacitor during an off time of the switching signal for generating the current feedback signal. The switching current signal is correlated to the switching current of the inductor, and the discharge current is generated in response to an input voltage of the inductor, an output voltage of the power converter, and the on time of the switching signal. | 06-13-2013 |
20130141056 | ADAPTIVE FREQUENCY COMPENSATION FOR PFC POWER CONVERTER OPERATING IN CCM AND DCM - A control circuit of a power factor correction (PFC) converter is provided. The control circuit includes a pulse width modulation (PWM) circuit, an amplifier, a detection circuit., and a capacitor. The PWM circuit generates a switching signal in response to a loop signal. The amplifier is coupled to generate the loop signal in response to a switching current. The detection circuit generates a mode signal coupled to change output impedance of the amplifier. The capacitor is coupled to the amplifier for loop frequency compensation. The switching signal is coupled to switch an inductor of the PFC power converter and generate the switching current. | 06-06-2013 |
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 |
20130063112 | CONTROLLER AND POWER CONVERTER USING THE SAME FOR CLAMPING MAXIMUM SWITCHING CURRENT OF POWER CONVERTER - A controller of a power converter is provided. The controller includes a feedback circuit, an output circuit, and a clamping circuit. The feedback circuit generates a feedback signal in accordance with output of the power converter. The output circuit generates a switching signal in accordance with the feedback signal for regulating the output of the power converter. The clamping circuit limits the feedback signal under a first level for a first load condition and limits the feedback signal under a second level for a second load condition. The clamping circuit includes a timer circuit. The timer circuit determines a slew rate of the feedback signal for increasing the feedback signal from the first level to the second level, and the second level is higher than the first level. | 03-14-2013 |
20130049812 | MONOLITHIC HIGH-SIDE SWITCH CONTROL CIRCUITS - A high-side switch control circuit is provided. The high-side switch control circuit includes an on/off transistor, a bias resistor, a zener diode, a level-shifting transistor, and a current source. The on/off transistor operates as a switch. The bias resistor is coupled to turn off the on/off transistor. The zener diode is coupled to clamp the maximum voltage of the on/off transistor. The level-shifting transistor is coupled to turn on the on/off transistor. The current source is coupled to the level-shifting transistor. The current source limits the maximum current of the level-shifting transistor. | 02-28-2013 |
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 |
20120306541 | HIGH-SIDE SIGNAL SENSING CIRCUIT - The present invention provides a high-side signal sensing circuit. The high-side signal sensing circuit comprises a signal-to-current converter, a second transistor and a resistor. The signal-to-current converter has a first transistor generating a mirror current in response to an input signal. The second transistor cascaded with the first transistor is coupled to receive the mirror current. The resistor generates an output signal in response to the mirror current. Wherein, the level of the output signal is corrected to the level of the input signal. | 12-06-2012 |
20120242252 | CONTROL CIRCUIT AND CONTROL METHOD FOR DIMMING LED LIGHTING CIRCUIT - The present invention provides a control circuit for dimming LED lighting. The control circuit comprises a voltage divider, a controller and an adaptive bleeder. The voltage divider receives an input voltage from an input terminal to generate a dimming signal. The controller generates a switching signal in response to the dimming signal. The controller further generates a control signal in response to the input voltage. The adaptive bleeder receives the control signal and draws a bleeder current from the input terminal in response to the control signal. | 09-27-2012 |
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 |
20120212287 | ADAPTIVE FILTER CIRCUIT FOR SAMPLING A REFLECTED VOLTAGE OF TRANSFORMER IN A POWER CONVERTER AND METHOD THEREOF - An adaptive filter circuit for sampling a reflected voltage of a transformer of a power converter includes a first switch for receiving the reflected voltage, a resistor having a first terminal and a second terminal, the first terminal of the resistor being coupled to the first switch, a capacitor coupled to the second terminal of the resistor for holding the reflected voltage, and a second switch coupled to the resistor in parallel, wherein the resistor and the capacitor develop a filter for sampling the reflected voltage which is sampled without filtering by the filter in a first period during a disable period of a switching signal and also sampled with filtering by the filter in a second period during the disable period of the switching signal. | 08-23-2012 |
20120206944 | CONTROL CIRCUIT FOR BURST SWITCHING OF POWER CONVERTER AND METHOD THEREOF - This invention provides a control circuit for burst switching of a power converter comprising: an adaptive circuit generating an adaptive threshold in response to a feedback signal correlated to an output load of the power converter; and a switching circuit generating a switching signal to switch a transformer of the power converter in accordance with the adaptive threshold and the feedback signal for regulating an output of the power converter. | 08-16-2012 |
20120206117 | MULTI-FUNCTION TERMINAL OF POWER SUPPLY CONTROLLER FOR FEEDBACK SIGNAL INPUT AND OVER-TEMPERATURE PROTECTION - The present invention provides a control circuit having a multi-function terminal. The control circuit comprises a switching circuit, a sample-and-hold circuit, a detection circuit, and a comparator. The sample-and-hold circuit is coupled to the multi-function terminal for generating a sample voltage by sampling the feedback signal during a first period. The detection circuit is coupled to the multi-function terminal during a second period for generating a detection voltage. The comparator compares the detection voltage and the sample voltage for generating an over-temperature signal, wherein the over-temperature signal is couple to disable the switching signal. | 08-16-2012 |
20120170330 | SINGLE-STAGE PFC CONVERTER WITH CONSTANT VOLTAGE AND CONSTANT CURRENT - An exemplary embodiment of a power converter is provided. The power converter includes a transformer, a power device, a switching controller, and a capacitor. The power device is coupled to the transformer for switching the transformer to product output of the power converter. The switching controller receives a feedback signal for generating a switching signal coupled to drive the power device. An input circuit of the switching controller is coupled to the transformer to sample an input signal for generating the feedback signal, and the input signal is correlated to the output of the power converter. The capacitor is coupled to the switching controller to provide frequency compensation for a feedback loop of the power converter. Input of the power converter is without an electrolytic capacitor, and a maximum output current of the power converter is a constant current. | 07-05-2012 |
20120170326 | Primary-side controlled power converter with an RC network and Method thereof - This invention provides a primary-side controlled power converter comprising: an RC network coupled to an auxiliary winding of a transformer of the primary-side controlled power converter to detect a reflected voltage of the transformer for generating a reflected signal, and a controller coupled to the RC network to receive the reflected signal for generating a switching signal; wherein the RC network develops a zero to provide a high-frequency path for shortening a rising time and a settling time of the reflected signal. | 07-05-2012 |
20120113551 | Method and Apparatus of Providing Over-Temperature Protection for Power Converters - The present invention provides a power converter. The power converter includes a transformer, a power switch and a controller. The transformer has a primary winding, a secondary winding and an auxiliary winding. The power switch is coupled to the primary winding of the transformer to regulate the power converter. The controller has an output terminal for generating a driving signal to switch the power switch in response to a switching signal. A thermal resistor is coupled to the output terminal of the controller. The driving signal is adjusted across the thermal resistor during an off-period of the switching signal. | 05-10-2012 |
20120081084 | Controller with Valley Switching and Limited Maximum Frequency for Quasi-Resonant Power Converters - A controller for a power converter is provided. The controller includes a PWM circuit, a detection circuit, a signal generation circuit and an oscillation circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to the PWM circuit to disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a signal waveform of the transformer. The signal generation circuit 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 pulse signal. The feedback signal is correlated to an output load of the power converter. The maximum frequency of the pulse signal is limited. | 04-05-2012 |
20120069611 | Correction Circuit of a Switching-Current Sample for Power Converters in Both CCM and DCM Operation - The present invention provides a correction circuit for a power converter. The correction circuit includes a sampling circuit, a demagnetizing-time circuit, a duty circuit, and a compensation circuit. The sampling circuit generates an average-current signal in response to a switching current of the power converter. The demagnetizing-time circuit generates a discharging-time signal in response to a switching signal and an input-voltage signal. The duty circuit generates a duty signal in response to the discharging-time signal, an on-time of the switching signal, and a switching period of the switching signal. The compensation circuit is coupled to receive the average-current signal and the duty signal for generating a corrected signal. The switching signal is utilized to switch a magnetic device for regulating an output voltage of the power converter. The corrected signal is coupled to generate the switching signal. | 03-22-2012 |
20120043843 | MOTOR ROTOR AND MOTOR HAVING THE MOTOR ROTOR - A motor rotor includes an annular body and a positioning protrusion installed on an inner lateral surface of the annular body. A magnetic body may be positioned by propping its lateral surface against the positioning protrusion, without the use of additional jigs. Therefore, the time needed to assemble the magnetic body to the annular body is saved, and the manufacturing cost of the whole motor is reduced. | 02-23-2012 |
20120033460 | High-Side Synchronous Rectifier Circuits and Control Circuits for Power Converters - A control circuit for a switching power converter is provided. The control circuit is installed between a secondary side and an output of the power converter and coupled to control a switching device. The control circuit includes a linear predict circuit, a reset circuit, a charge/discharge circuit, and a PWM circuit. The linear predict circuit is coupled to receive a linear predict signal from the secondary side for generating a charging signal. The reset circuit is couple to receive a resetting signal for generating a discharging signal. The charge/discharge circuit is coupled to receive the charging signal and the discharging signal for generating a ramp signal. The PWM circuit is coupled to receive the linear predict signal for enabling a switching signal and receive the ramp signal for resetting the switching signal. | 02-09-2012 |
20120025655 | MOTOR ROTOR AND MOTOR HAVING THE MOTOR ROTOR - A motor rotor includes an annular body and a magnetic body installed on an inner lateral surface of the annular body. The magnetic body has a first curved surface and a second curved surface opposing the first curved surface. The magnetic body props against the inner lateral surface of the annular body via the first curved surface. The first curved surface has a first curvature less than a second curvature of the second curved surface. Because the magnetic body of the motor rotor has an uneven thickness, and an air gap interval formed between the motor rotor and the stator also has an uneven width, forces applied to a region where the magnetic forces change directions are smooth. Therefore, the vibration of the whole motor is reduced, and the noises are suppressed effectively. | 02-02-2012 |
20110305053 | Switching Control Circuits with Valley Lock for Power Converters - A switching control circuit for a switching power converter is provided. The switching control circuit is coupled to a switching device and an auxiliary winding of a transformer. The switching control circuit includes a valley detecting circuit, a valley lock circuit, and a PWM circuit. The valley detecting circuit is coupled to receive a reflected voltage signal from the auxiliary winding of the transformer for outputting a control signal in response to the reflected voltage signal. The valley lock circuit is coupled to receive the control signal for outputting a judging signal in response to the control signal during a first period and a second period following the first period. The PWM circuit outputs a switching signal in response to the judging signal. | 12-15-2011 |
20110292702 | METHOD AND APPARATUS TO IMPROVE DYNAMIC RESPONSE OF THE SYNCHRONOUS RECTIFYING FOR RESONANT POWER CONVERTERS - A synchronous rectifying circuit for a switching power converter is provided. The synchronous rectifying circuit includes a power transistor, a diode, and a control circuit. The power transistor and the diode are coupled to a transformer and an output of the power converter for rectification. The control circuit generates a drive signal to switch on the power transistor once the diode is forward biased. The control circuit includes a monitor circuit. The monitor circuit generates a monitor signal an off signal to switch off the power transistor in response to a pulse width of the drive signal for generating an off signal to switch off the power transistor. The monitor circuit further reduces the pulse width of the drive signal in response to a change of a feedback signal. The feedback signal is correlated to an output load of the power converter. | 12-01-2011 |
20110267850 | Method and Apparatus of Operating a Primary-Side-Regulation Power Converter at Both Continuous Current Mode and Discontinuous Current Mode - A method and an apparatus of operating a primary-side-regulation power converter at both continuous current mode and discontinuous current mode are provided. The apparatus includes a switching circuit, a signal generator, a correlation circuit, and a feedback modulator. The signal generator generates a half signal and a second sampling pulse in response to a switching signal. The correlation circuit receives the half signal, the second sampling pulse and a switching-current signal for generating a modulating current. The feedback modulator modulates a feedback signal in response to the modulating current, a detection signal and the switching signal. The detection signal obtained from a transformer is correlated to an output voltage of the primary-side-regulation power converter. An on-period of the half signal is half of an on-period of the switching signal. The switching-current signal is sampled at a falling-edge of the half signal. | 11-03-2011 |
20110255309 | High-Speed Reflected Signal Detection for Primary-Side Controlled Power Converters - A controller for a power converter includes a clamping circuit, a switching circuit and a pulse generator. The clamping circuit is coupled to an input terminal of the controller for detecting a detection signal from a transformer. The switching circuit generates a switching signal to switch the transformer in response to the detection signal for regulating the power converter. A maximum level of the detection signal is clamped to be under a level of a threshold voltage during an off-period of the switching signal. Since the maximum level of the detection signal is clamped and the oscillating energy of the reflected signal is discharged, the speed of detecting the detection signal is increased. Therefore, the regulation of the primary-side controlled power converter can be improved accordingly. | 10-20-2011 |
20110254498 | Constant-Speed Control Circuit for BLDC Motors - A speed-control circuit for a BLDC motor is provided. The speed-control circuit includes a pulse generator, a current source circuit, a filter circuit, an error amplification circuit and a PWM circuit. The pulse generator detects a speed signal of the BLDC motor to generate a pulse signal. The filter circuit is coupled to the current source circuit to generate an average signal. The error amplification circuit receives the average signal and a speed-reference signal for generating a speed-control signal. The PWM circuit generates a switching signal to drive the BLDC motor in response to the speed-control signal. A pulse width of the switching signal is determined by the speed-control signal. | 10-20-2011 |
20110038183 | SWITCHING REGULATOR HAVING TERMINAL FOR FEEDBACK SIGNAL INPUTTING AND PEAK SWITCHING CURRENT PROGRAMMING - A switching regulator of a power converter is provided and includes a feedback-input circuit, a programming circuit, and a peak-current-threshold circuit. The feedback-input circuit is coupled to a terminal of the switching regulator for receiving a feedback signal. The feedback-input circuit is operated in a first range of a terminal signal. The programming circuit is coupled to the terminal for generating a programming signal. The programming signal is operated in a second range of the feedback signal. The peak-current-threshold circuit generates a threshold signal in accordance with the programming signal. The feedback signal is coupled to regulate the output of the power converter, and the threshold signal is coupled to limit a peak switching current of the power converter. | 02-17-2011 |
20110037443 | PARALLEL CONNECTED PFC CONVERTER - A parallel PFC converter comprises a first PFC circuit, a second PFC circuit, and a voltage divider. The second PFC circuit is connected in parallel with the first PFC circuit for generating an output voltage of the parallel PFC converter. The voltage divider is coupled to receive the output voltage for generating a first feedback signal and a second feedback signal. The first feedback signal is higher than the second feedback signal. The first PFC circuit and the second PFC circuit respectively comprises a first switching control circuit and a second switching control circuit for regulating the output voltage. It is an object of the present invention to reduce the power loss for improving the efficiency of the PFC converter. | 02-17-2011 |
20100309645 | MOUNTING STRUCTURE FOR AN ELECTRONIC ELEMENT - A mounting structure for fixing an electronic element on a heat dissipation unit is provided. The mounting structure includes a heat dissipation unit, a fixing member, electronic elements and elastic elements. The fixing member is fixed on the heat dissipation unit. The elastic elements are sandwiched between the electronic elements and the fixing member, wherein the fixing member and the elastic elements press the electronic elements to make the electronic elements tightly contact the heat dissipation unit. | 12-09-2010 |
20100232182 | DUAL-SWITCHES FLYBACK POWER CONVERTER WITH SELF-EXCITED SUPPLY TO POWER THE HIGH-SIDE DRIVER - An exemplary embodiment of a flyback power converter includes a transformer for power transfer, a high-side transistor, a low-side transistor, two diodes, a control circuit, and a high-side drive circuit. The high-side transistor and the low-side transistor are coupled to switch the transformer. The two diodes are coupled to said transformer to circulate energy of leakage inductance of the transformer to an input power rail of the power converter. The control circuit generates a switching signal coupled to control the high-side transistor and the low-side transistor. The high-side drive circuit is coupled to receive the switching signal for driving the high-side transistor. The transformer has an auxiliary winding generating a floating power to provide power supply for said high-side drive circuit. | 09-16-2010 |
20100230749 | SEMICONDUCTOR DEVICES AND FORMATION METHODS THEREOF - A semiconductor device is provided and includes a substrate of a first conductivity type, a deep well of a second conductivity type, and a first high-side device. The deep well is formed on the substrate. The first high-side device is disposed within the deep well and includes an insulation layer of the second conductivity type, a well of the first conductivity type, first and second regions of the second conductivity type, and a first poly-silicon material. The insulation layer is formed on the substrate. The well is formed within the deep well. The first and second regions are formed within the well. The first poly-silicon material is disposed between the first region and the second region and on the deep well. | 09-16-2010 |
20100202163 | FLYBACK POWER CONVERTERS - A dual-switch flyback power converter includes a control circuit to generate a switching signal. A high-side driving circuit includes a pulse generation circuit. The pulse generation circuit generates a pulse-on signal and a pulse-off signal to control two transistors in response to the switching signal. The two transistors further respectively provide a level-shift-on signal and a level-shift-off signal to a comparison circuit to enable/disable a high-side driving signal. Without using a charge pump circuit to power the high-side driving circuit, a floating winding of a transformer is utilized to provide a floating voltage to power the high-side driving circuit, which reduces the cost of the dual-switch flyback power converter and ensures a sufficient high-side driving capability of the high-side driving circuit. | 08-12-2010 |
20100202162 | ASYMMETRICAL RESONANT POWER CONVERTERS - A resonant power converter is provided and includes a capacitor, an inductive device, a first transistor, a second transistor, and a control circuit. The capacitor and the inductive device develop a resonant tank. The first transistor and the second transistor are coupled to switch the resonant tank. The control circuit generates a first signal and a second signal to control the first transistor and the second transistor respectively. Frequencies of the first signal and the second signal are changed for regulating output of the resonant power converter. The control circuit is further coupled to detect an input voltage of the resonant power converter. A pulse width of the second signal is modulated in response to change of the input voltage. | 08-12-2010 |
20100201334 | SYNCHRONOUS RECTIFIER HAVING PHASE LOCK CIRCUIT COUPLED TO FEEDBACK LOOP FOR RESONANT POWER CONVERTERS - A synchronous rectifier for a switching power converter is provided and includes a power transistor, a diode, and a control circuit. The power transistor and the diode are coupled to a transformer and an output of the power converter for the rectification. The control circuit generates a drive signal to switch on the power transistor once the diode is forward biased. The control circuit includes a phase-lock circuit. The phase-lock circuit generates an off signal to switch off the power transistor in response to a pulse width of the drive signal. The pulse width of the drive signal is shorter than a turned-on period of the diode. The phase-lock circuit further reduces the pulse width of the drive signal in response to a feedback signal. The feedback signal is correlated to an output load of the power converter. | 08-12-2010 |
20100182804 | SWITCHING CIRCUIT FOR PRIMARY-SIDE REGULATED RESONANT POWER CONVERTERS - The present invention provides a switching circuit to regulate an output voltage and a maximum output current at the primary side of a resonant power converter. The switching circuit includes a pair of switching devices and a controller. The controller is coupled to a transformer to sample a voltage signal thereof and generates switching signals to control the switching devices. The switching frequency of the switching signals is increased in response to the decrease of the output voltage. The increase of the switching frequency of the switching signals decreases the power delivered to the output of the resonant power converter. The output current is therefore regulated. | 07-22-2010 |
20100172156 | OFFLINE SYNCHRONOUS RECTIFIER CIRCUIT WITH TURNED-ON ARBITER AND PHASE-LOCK FOR SWITCHING POWER CONVERTERS - A synchronous rectifier circuit of a switching power converter is provided and includes first and second power transistors and first and second diodes connected to a transformer and an output of the power converter for rectifying. An arbiter circuit generates a lock signal to prevent the second power transistor from being turned on when the first diode the first power transistor is turned on. A controller generates a drive signal to control the first power transistor according to an on signal and an off signal. A phase-lock circuit generates the off signal according to the on signal. The on signal is enabled once the first diode is forward biased. The one signal enables the drive signal for turning on the first power transistor. The off signal disables the drive signal for turning off the first power transistor. The off signal is enabled before the disabling of the on signal. | 07-08-2010 |
20100123563 | POWER MANAGEMENT INTERFACE - A power management interface is provided and includes a switch, a transmitting circuit, and a receiving circuit. The switch is coupled to an AC power line for controlling a power line signal to a load. The transmitting circuit generates a switching signal to control the switch and achieve a phase modulation to the power line signal in response to a transmitting-data. The receiving circuit is coupled to receive the power line signal for detecting a phase of the power line signal and generating a receiving-data to control power of the load. The receiving-data is generated in accordance with the phase detection of the power line signal and correlated to the transmitting-data. | 05-20-2010 |
20100109465 | MOTOR STRUCTURE AND FAN - A motor structure and a fan are provided. The motor structure includes a shaft, a motor control panel, a stator, a rotor and a motor housing. The motor control panel has a first fastening portion and is engageable with the shaft. The stator has a second fastening portion coupled to the first fastening portion so as to fasten the motor control panel to the stator, thereby reducing the overall size and saving costs of materials. The rotor corresponds in position to the stator and is pivotally connected to the shaft. The motor housing is pivotally connected to the shaft and encloses the shaft, the motor control panel, the stator, and the rotor. The fan includes the motor structure and a fan blade element. | 05-06-2010 |
20100007317 | BUCK-BOOST PFC CONVERTERS - A buck-boost PFC converter is provided and includes an inductor, first and second transistors, a first diode, and a control circuit. The inductor has a first terminal and a second terminal. The first transistor is coupled to a positive-power rail and the first terminal of the inductor. The second transistor is coupled to the second terminal of the inductor and a negative-power rail. The first diode is connected from the second terminal of the inductor to an output of the buck-boost PFC converter. The control circuit generates a first signal and a second signal coupled to control the first transistor and the second transistor respectively. The first signal is utilized to turn on the first transistor for conducting the positive-power rail to the inductor. The second signal is utilized to turn on the second transistor for conducting the inductor to the negative-power rail. | 01-14-2010 |
20100007295 | OVER-TORQUE CONTROL CIRCUIT FOR BLDC MOTORS - A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit determines the maximum torque and the maximum speed of the BLDC motor. The control circuit includes an over-current detection circuit to generate a reset signal in response to a switching current of the BLDC motor. The reset signal is generated when the switching current of the BLDC motor exceeds a threshold. A pulse width of the PWM signal is correlated to the level of a speed-control signal and the level of the torque-control signal. The pulse width of the PWM signal is also controlled by the reset signal generated by the over-current detection circuit. | 01-14-2010 |
20090310388 | METHOD AND APPARATUS FOR MEASURING THE SWITCHING CURRENT OF POWER CONVERTER OPERATED AT CONTINUOUS CURRENT MODE - An apparatus for detecting a switching current of the power converter, wherein the apparatus includes a signal generation circuit, a sample-and-hold circuit, and a calculating circuit. The signal generation circuit generates a sample signal in accordance with the pulse width of a switching signal. The sample-and-hold circuit is coupled to receive the sample signal and switching current signal for generating a first current signal and a second current signal. The calculating circuit is coupled to receive the first current signal and the second current signal for generating output signals. The switching signal is used for switching the magnetic device of the power converter, and the switching current signal is correlated to the switching current of the power converter; the output signals are correlated to the value of the switching current of the power converter. | 12-17-2009 |
20090309526 | CONTROL CIRCUIT WITH DUAL PROGRAMMABLE FEEDBACK LOOPS FOR BLDC MOTORS - A BLDC (brushless direct current) motor system of the present invention includes a control circuit, a sequencer, a driving circuit, and a BLDC motor. The control circuit comprises a speed-feedback loop and a torque-feedback loop to control the maximum speed and the maximum torque of the BLDC motor in parallel configuration. The speed-feedback loop generates a speed-control signal. The torque-feedback loop generates a torque-control signal. A PWM circuit receives the speed-control signal and the torque-control signal to generate a PWM signal. A pulse width of the PWM signal is correlated to the level of the speed-control signal and/or the level of the torque-control signal. | 12-17-2009 |
20090309448 | END COVER AND MOTOR ROTOR HAVING THE END COVER - An end cover adapted to engage with an end surface of a spindle of a motor rotor is proposed for securely coupling to the spindle with a plurality of permanent magnets disposed around the peripheral wall of the spindle. The end cover has a first surface facing an end surface of the spindle and an second surface opposing to the first surface, which is formed with a plurality of inserting slots indentedly disposed around the rim thereof and corresponding to the permanent magnets for coupling the ends of the permanent magnets, thereby securely fastening each of the permanent magnets to the spindle of the motor rotor. Further, the present invention further provides a motor rotor having the end covers described above. | 12-17-2009 |
20090309441 | SENSOR FASTENING METHOD AND SENSOR FASTENING FRAME FOR USE THEREWITH - A sensor fastening method and a sensor fastening frame for use therewith are provided. The sensor fastening frame is coupled to a motor stator of a brushless motor having distributed coils and extends over the distributed coils to allow the sensor fastening frame to rotate about the axle of a motor rotor, without interference with the distributed coils. At least a sensor is fastened in position to the sensor fastening frame proximate to one end of the axle of the motor stator for positioning the sensor to detect magnetic field variations of the motor rotor. | 12-17-2009 |
20090213626 | SWITCHING CONTROLLER CAPABLE OF REDUCING ACOUSTIC NOISE FOR POWER CONVERTERS - The present invention provides a switching controller capable of reducing acoustic noise of a transformer for a power converter. The switching controller includes a switching circuit, a comparison circuit, an activation circuit, and an acoustic-noise eliminating circuit. The acoustic-noise eliminating circuit comprises a first-check circuit, a second-check circuit, a pulse-shrinking circuit, and a limit circuit. The first-check circuit receives a switching-current signal which is correlated to a switching current of the power converter and a PWM signal to generate a trigger signal. The second-check circuit receives the trigger signal to generate a control signal. When the frequency of the trigger signal falls into audio band, the control signal will be enabled to limit the switching current. Therefore, the acoustic noise of the transformer can be eliminated. | 08-27-2009 |
20090213623 | METHOD AND APPARATUS OF PROVIDING SYNCHRONOUS REGULATION CIRCUIT FOR OFFLINE POWER CONVERTER - A synchronous regulation circuit is provided. A secondary-side switching circuit is coupled to the output of the power converter to generate a synchronous signal and a pulse signal in response to an oscillation signal and a feedback signal. An isolation device transfers the synchronous signal from the secondary side to the primary side of the power converter. A primary-side switching circuit receives the synchronous signal to generate a switching signal for soft switching a transformer. The pulse signal is utilized to control a synchronous switch for rectifying and regulating the power converter. The synchronous switch includes a power switch and a control circuit. The control circuit receives the pulse signal for turning on or off the power switch. The power switch is connected between the transformer and the output of the power converter. A flyback switch is operated as a synchronous rectifier to freewheel the inductor current of the power converter. The flyback switch is turned on in response to the off state of the power switch. The turn-on period of flyback switch is correlated to the turn-on period of the power switch. | 08-27-2009 |
20090195101 | MOTOR ROTOR - A motor rotor is provided. The motor rotor includes a plurality of magnetic members circumferentially disposed on a peripheral wall surface of a turning axle of the motor rotor, and both end surfaces of the turning axle are coupled with fastening members respectively; each of the magnetic members has a first fastening portion formed at each of its two ends; and the fastening member is provided with a plurality of second fastening portions corresponding in position to the first fastening portions, such that each of the magnetic members are firmly fixed in position to the turning axle. | 08-06-2009 |
20090109715 | SYNCHRONOUS RECTIFYING FOR SOFT SWITCHING POWER CONVERTERS - An synchronous rectifying apparatus or synchronous rectifying circuit of a soft switching power converter is provided to improve the efficiency. The integrated synchronous rectifying circuit includes: a power transistor connected from a transformer to the output of the power converter for rectifying; a controller having a latch circuit generates a drive signal to control the power transistor in response to a switching signal generated by a winding of the transformer in response to the switching of the transformer. The controller turns off the power transistor when the switching signal is lower than a low-threshold. The power transistor is turned on when the switching signal is higher than a high-threshold. Furthermore, a maximum-on-time circuit provided in the controller is applied to generate a maximum-on-time signal for limiting the maximum on time of the power transistor. | 04-30-2009 |
20090091960 | METHOD AND APPARATUS FOR SYNCHRONOUS RECTIFYING OF SOFT SWITCHING POWER CONVERTERS - An apparatus for synchronous rectifying of a soft switching power converter is provided. An integrated synchronous rectifier includes a power transistor coupled between a transformer and the output of the soft switching power converter, and a controller receiving a pulse signal to switch on/off the power transistor. A switching control circuit generates the pulse signal in response to a current signal, and generates drive signals to switch the transformer in response to a switching signal. An isolation device is coupled to transfer the pulse signal between the switching control circuit and the integrated synchronous rectifier. The switching signal is used for regulating the power converter and the current signal is correlated to the switching current of the transformer. | 04-09-2009 |
20090091304 | CONTROL CIRCUIT FOR MULTI-PHASE, MULTI-CHANNELS PFC CONVERTER WITH VARIABLE SWITCHING FREQUENCY - A switching control circuit for multi-phases PFC converters is provided. It includes a PFC-control circuit coupled to receive a first-inductor signal and a feedback signal for generating a first-switching signal. The first-switching signal is utilized to switch the first inductor for power factor correction. A phase-detection circuit detects the first-switching signal and a second-inductor signal for generating a start signal and a phase-lock signal. The start signal is developed to enable a second-switching signal. The second-switching signal is coupled to switch a second inductor. An on-time-adjust circuit is coupled to adjust the on time of the second-switching signal in accordance with the phase-lock signal. The phase-lock signal is correlated to the period between the end of the second-inductor signal and the start of the second-switching signal. | 04-09-2009 |
20080291701 | POWER CONVERTER FOR COMPENSATING MAXIMUM OUTPUT POWER AND PWM CONTROLLER FOR THE SAME - A PWM controller compensates a maximum output power of a power converter, and includes a PWM unit and a compensation circuit. The PWM unit generates a PWM signal for controlling a power switch to switch a power transformer, which has a primary winding connected to the power switch and is supplied with an input voltage of the power converter. A pulse width of the PWM signal is correlated to an amplitude of the input voltage. The compensation circuit generates a current boost signal in response to the PWM signal by pushing up a peak value of a current-sense signal generated by a current-sense device in response to a primary-side switching current of the power transformer. A peak value of the current boost signal is adjusted by the pulse width of the PWM signal for compensating a difference of the maximum output power caused by the amplitude of the input voltage. | 11-27-2008 |
20080291700 | POWER CONVERTER HAVING PWM CONTROLLER FOR MAXIMUM OUTPUT POWER COMPENSATION - A PWM controller compensates a maximum output power of a power converter having a power switch. The PWM controller includes an oscillator for generating a saw signal and a pulse signal, a power limiter coupled to the oscillator for generating a saw-limited signal in response to the saw signal, and a PWM unit coupled to the power limiter and the oscillator to generate a PWM signal for controlling the power switch in response to the saw-limited signal and the pulse signal. The saw-limited signal has a level being flattened during a period of time before an output voltage is generated, and is then transformed to a saw-limited waveform after the period of time. | 11-27-2008 |
20080198636 | SWITCHING CONTROLLER FOR PARALLEL POWER SUPPLY - A switching controller for a parallel power supply is disclosed. The switching controller includes an input circuit coupled to an input terminal to receive an input signal for generating a phase-shift signal, a first integration circuit coupled to the input circuit to generate a first integration signal in response to a pulse width of the input signal, and a control circuit coupled to the first integration circuit to generate a switching signal for switching the power supply, the switching signal being enabled in response to the phase-shift signal, a pulse width of the switching signal being determined in accordance with the first integration signal. | 08-21-2008 |
20080197708 | SWITCHING CONTROLLER FOR POWER SHARING OF PARALLEL POWER SUPPLIES - A switching controller for power sharing of power supplies is disclosed. The switching controller includes an input circuit coupled to an input terminal to receive an input signal for generating a phase-shift signal, a first integration circuit coupled to the input circuit to generate a first integration signal in response to a pulse width of the input signal, and a control circuit coupled to the first integration circuit to generate a switching signal for switching the power supply, wherein the switching signal is enabled in response to the phase-shift signal, and a pulse width of the switching signal is determined in accordance with the first integration signal. | 08-21-2008 |