Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.

Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.

Abstract: A fast transient response converter is disclosed which makes use of stepping inductor in a switching converter to speed up output voltage response under fast transient condition. The inductive element in a switching converter is replaced by two series or parallel inductive elements, one of which has a smaller value of inductance than the other. During the fast transient period, the inductor with larger inductance value will be shorted to a voltage source. The total inductance will be greatly reduced and thus allows rapid current change during the transient change.

Abstract: A power converter includes a boost converter, a DC/DC converter and a coupler chain. The boost converter receives a rectified AC input and generates a high voltage output. The boost converter includes a zero-voltage-switching transistor that is operable to adjust the power factor of the rectified AC input to generate the high voltage output. The DC/DC converter is coupled to the high voltage output of the boost converter and is configured to generate a regulated output voltage. The DC/DC converter includes a complementary pair of zero-voltage-switching transistors that are operable to regulate the high voltage output of the boost converter to generate the regulated output voltage.

Abstract: A fast transient response converter is disclosed which makes use of stepping inductor in a switching converter to speed up output voltage response under fast transient condition. The inductive element in a switching converter is replaced by two series or parallel inductive elements, one of which has a smaller value of inductance than the other. During the fast transient period, the inductor with larger inductance value will be shorted to a voltage source. The total inductance will be greatly reduced and thus allows rapid current change during the transient change.

Abstract: An AC-DC converter that includes a plurality of power conversion units that overlay their signals to generate a DC signal with low voltage level, small voltage and current ripples, but high DC current. The DC signal is further filtered by a LC low pass filter to further minimize the ripples before output to the load. In one embodiment, the plurality of power conversion units is preferably powered by a plurality of input pulse generators. In an alternative embodiment, the power conversion units is powered by a input pulse generator circuit that includes a plurality of n-channel MOSFETs arranged in a full bridge configuration whose gate voltages are controlled by a plurality of pulse generators.

Abstract: A power converter includes a boost converter, a DC/DC converter and a coupler chain. The boost converter receives a rectified AC input and generates a high voltage output. The boost converter includes a zero-voltage-switching transistor that is operable to adjust the power factor of the rectified AC input to generate the high voltage output. The DC/DC converter is coupled to the high voltage output of the boost converter and is configured to generate a regulated output voltage. The DC/DC converter includes a complementary pair of zero-voltage-switching transistors that are operable to regulate the high voltage output of the boost converter to generate the regulated output voltage.

Abstract: An AC-DC converter that includes a plurality of power conversion units that overlay their signals to generate a DC signal with low voltage level, small voltage and current ripples, but high DC current. The DC signal is further filtered by a LC low pass filter to further minimize the ripples before output to the load. In one embodiment, the plurality of power conversion units is preferably powered by a plurality of input pulse generators. In an alternative embodiment, the power conversion units is powered by a input pulse generator circuit that includes a plurality of n-channel MOSFETs arranged in a full bridge configuration whose gate voltages are controlled by a plurality of pulse generators.

Abstract: A synchronous rectifier using current driven approach is disclosed which can replace diode rectifier in most of the power converter topologies to enable low rectification loss. The present invention comprises a low loss switch and essentially a transformer with at lease one current sensing winding, windings for current sense energy recovery and one driving winding connected to a hysterisis driver which provides driving signal and power for the synchronous rectifier. A hystersis driver is introduced which can reduce the noise interference to the driving signal, increase the operating frequency range, eliminate the saturation problem of the current sensing transformer and hence provide more flexibility to the transformer design. This synchronous rectifier is self-driven and the driving signal is independent of the input voltage of the converter which enhances its application to wide input range converter. Current sense energy recovery enables power converters to operate at high efficiency and high frequency.

Abstract: An efficient power driver for color light emitting diodes (LED) is disclosed for driving multiple LEDs for producing different desired colors. Such LED combinations comprising LEDs with different primary colors are suitable for implementing pixels in displaying a digitized image. This disclosed invention provides switching power conversion embodiments such that a single apparatus drives different color LEDs. Furthermore, the disclosed invention provides configurations with and without input to output isolation while enabling control of the current through each LED, for instance by an inductor or operating condition.

Abstract: An AC/DC power converter includes a pair of input terminals, a boost unit, a DC/DC converter, a coupler chain, and a discharge chain. The pair of input terminals connect to a pulsating DC source. The boost unit is coupled to the input terminals and generates a voltage higher than the voltage at the input terminals. The DC/DC converter couples to the boost unit and includes a set of series switches coupled to the primary side of a transformer through a series inductor and capacitor. The DC/DC converter further includes a secondary winding coupled to the transformer and coupled to a rectifier and filter configuration. The coupler chain couples the boost unit to the DC/DC converter. The discharge chain couples the coupler chain to the high voltage source generated by the boost unit. Control pulses synchronize the series switches so that a resonant current flows in the coupler chain and the discharge chain such that the switches can be turned on and off while voltages across the switches are substantially zero.

Abstract: An AC/DC power converter includes a pair of input terminals, a boost unit, a DC/DC converter, a coupler chain, and a discharge chain. The pair of input terminals connect to a pulsating DC source. The boost unit is coupled to the input terminals and generates a voltage higher than the voltage at the input terminals. The DC/DC converter couples to the boost unit and includes a set of series switches coupled to the primary side of a transformer through a series inductor and capacitor. The DC/DC converter further includes a secondary winding coupled to the transformer and coupled to a rectifier and filter configuration. The coupler chain couples the boost unit to the DC/DC converter. The discharge chain couples the coupler chain to the high voltage source generated by the boost unit. Control pulses synchronize the series switches so that a resonant current flows in the coupler chain and the discharge chain such that the switches can be turned on and off while voltages across the switches are substantially zero.

Abstract: A noise canceling apparatus is provided that uses magnetically-coupled windings to cancel noise currents or noise voltages from a power converter. The apparatus may include a series voltage source or a shunt current source that is placed at input or output terminals of a power converter to eliminate the noise generated from the power converter.

Abstract: A fast transient response power converter is disclosed which makes use of a variable inductor to speed up the converter's output voltage response under fast transient conditions. The inductive element in a switching converter is replaced by two series or parallel inductive elements of which one has a smaller inductance value and the other has a larger inductance value. During the fast transient condition, the total inductance is greatly reduced to allow rapid current change during the transient condition.