Patent application number | Description | Published |
20130154496 | MULTI-MODE FLYBACK CONTROL FOR A SWITCHING POWER CONVERTER - In at least one embodiment, an electronic system and method includes a controller to control a switching power converter in at least two different modes of operation depending on whether the controller detects a dimmer or not and/or whether a load requests more power than either of the two operational modes can provide. In at least one embodiment, the controller detects whether a dimmer is phase cutting an input voltage to a switching power converter. The controller operates the switching power converter in a first mode if the dimmer is detected, and the controller operates the switching power converter in a second mode if the dimmer is not detected. The controller also transitions between operating the switching power converter in the first mode and the second mode if a status of detection of the dimmer changes. | 06-20-2013 |
20130155728 | Isolation of Secondary Transformer Winding Current During Auxiliary Power Supply Generation - An electronic system and method include a controller to actively control power transfer from a primary winding of a switching power converter to an auxiliary-winding of an auxiliary power supply. The switching power converter is controlled and configured such that during transfer of power to the auxiliary-winding, the switching power converter does not transfer charge to one or more secondary-windings of the switching power converter. Thus, the switching power converter isolates one or more secondary transformer winding currents from an auxiliary-winding current. By isolating the charge delivered to the one or more secondary-windings from charge delivered to the auxiliary-winding, the controller can accurately determine an amount of charge delivered to the secondary-windings and, thus, to a load. | 06-20-2013 |
20140028095 | ACCELERATION OF OUTPUT ENERGY PROVISION FOR A LOAD DURING START-UP OF A SWITCHING POWER CONVERTER - An electronic system and method include a controller to operate in a start-up mode to accelerate driving a load to an operating voltage and then operates in a post-start-up mode. A start-up condition occurs when the controller detects that a load voltage is below a predetermined voltage threshold level. The predetermined voltage threshold level is set so that the controller will boost the voltage to an operating value of a load voltage at a faster rate than during normal, steady-state operation. The controller causes a switching power converter to provide charge to the load at a rate in accordance with a start-up mode until reaching an energy-indicating threshold. When the energy-indicating threshold has been reached, the controller causes the switching power converter to (i) decrease the amount of charge provided to the load relative to the charge provided during the start-up mode and (ii) operate in a distinct post-start-up-mode. | 01-30-2014 |
20140252975 | Reduction of Supply Current Variations Using Compensation Current Control - A power distribution system and method includes a controller that is configured to control a switching power converter. In at least one embodiment, the controller includes a compensation current control circuit to control a compensation current that reduces and, in at least one embodiment, approximately eliminates variations in current drawn by the controller during a particular operational time period. In at least one embodiment, the power distribution system is a lamp that includes the controller, a switching power converter, and one or more light sources, such as light emitting diodes. | 09-11-2014 |
20140252990 | Quantization Error Reduction in Constant Output Current Control Drivers - An electronic system and method includes a controller to control a switching power converter in at least two different modes of operation, a normal mode and an error reduction mode. The controller controls an amount of charge pushed (i.e. delivered) by the switching power converter to a load to reduce a charge quantization error. The charge quantization error represents an amount of charge pushed to the load beyond a target charge amount. The controller determines an amount of charge to be pushed to the toad. Based on the amount of charge to be pushed to the load, the controller generates a current control signal that controls a current control switch in the switching power converter. Determination of the control signal depends on whether the controller is operating in normal mode or error reduction mode. The controller attempts to reduce the charge quantization error to avoid power fluctuations. | 09-11-2014 |
20140265893 | HIGH-EFFICIENCY LIGHTING DEVICES HAVING DIMMER AND/OR LOAD CONDITION MEASUREMENT - A circuit for powering high-efficiency lighting devices from a thyristor-controlled dimmer includes a power converter for powering the high-efficiency lighting devices from input terminals of the circuit. The circuit also includes a control circuit that controls the input current drawn by the input terminals at least while the power converter transfers energy to the lighting devices. The circuit also includes a sensing circuit that determines or measures at least one attach current characteristic at the input terminals and stores an indication of the characteristic for subsequent operation of the control circuit. | 09-18-2014 |
20140265916 | Controlled Electronic System Power Dissipation via an Auxiliary-Power Dissipation Circuit - An electronic system and method include a controller to actively control transfer of excess energy to an auxiliary-winding of an auxiliary power dissipation circuit. The excess energy is a transfer of energy from a primary winding of a switching power converter to the auxiliary-winding of the auxiliary power dissipation circuit. In at least one embodiment, the electronic system is a lighting system that includes a triac-based dimmer. The excess energy is energy drawn through the primary-side winding of the switching power converter to provide operational compatibility between a dimmer through which a power supply provides energy to the switching power converter and a load to which the switching power converter provides energy. | 09-18-2014 |
20140265933 | SYSTEM AND METHOD FOR LEARNING DIMMER CHARACTERISTICS - Systems and methods for learning dimmer characteristics provide improved efficiency in operating lighting devices. In one embodiment, an apparatus includes a lamp controller that is configured to monitor voltage information associated with one or more lamps or a dimmer of a system, adjust one or more parameters of an attach current profile in conformity with the voltage information to arrive at a selected attach current profile, and apply within the system the selected attach current profile. | 09-18-2014 |
20140339999 | CHARGE PUMP-BASED DRIVE CIRCUITRY FOR BIPOLAR JUNCTION TRANSISTOR (BJT)-BASED POWER SUPPLY - A bipolar junction transistor (BJT) may be used to generate a supply voltage for operating a controller, such as a lighting controller for a LED-based light bulb. A base of the BJT may receive current generated from the supply voltage to control operation of the BJT. Although the base of the BJT would be at a lower voltage than the emitter, a base drive circuit may be coupled between the emitter and the base of the BJT to increase the voltage. As one example, the base drive circuit may be a charge pump. In another example, the BJT may function as its own charge pump. In yet another example, a positive and a negative base current of the BJT may be independently controlled to regulate an output supply voltage V | 11-20-2014 |
20150028764 | TWO TERMINAL DRIVE OF BIPOLAR JUNCTION TRANSISTOR (BJT) FOR SWITCH-MODE OPERATION OF A LIGHT EMITTING DIODE (LED)-BASED BULB - A bipolar junction transistor (BJT) may be used in a power stage DC-to-DC converter, such as for LED-based light bulbs. The BJT may be switched on and off from a controller coupled to two terminals of the BJT. Through the two terminals, the control IC may dynamically adjust a reverse recovery time period of the BJT. The reverse recovery time period may be adjusted by changing an amount of base charge that accumulates on the BJT. Additional, the reverse recovery may be controlled through the use of a reverse base current source applied to the BJT after beginning switching off the BJT. | 01-29-2015 |
20150028768 | COMPENSATING FOR A REVERSE RECOVERY TIME PERIOD OF A BIPOLAR JUNCTION TRANSISTOR (BJT) IN SWITCH-MODE OPERATION OF A LIGHT-EMITTING DIODE (LED)-BASED BULB - A turn-off transition time period, also referred to as a reverse recovery time period, may be compensated for by a controller of a power stage including a bipolar junction transistor (BJT). The reverse recovery time period may be measured in one switching cycle and a subsequent switching cycle may include compensations based on the measured reverse recovery time period. That is the switching on and off of the BJT may be compensated to obtain a desired average output current to a load. When the reverse recovery time period is known, an error in the peak current obtained due to the reverse recovery time period may be calculated. The calculated error may be used to offset the target peak current for controlling the switching of the BJT to begin a turn-off transition of the BJT earlier in a switching cycle and thus reduce error in peak current at the BJT. | 01-29-2015 |