Power Integrations, Inc.

Christian Pura Angeles

Jose Requinton Del Carmen, Jr

Peter Vaughan

Marvin Espino

Chunming Guo

A bleeder circuit includes an input current sense circuit, coupled to one of first and second input terminals of a driver circuit, to output a bleeder on/off signal in response to an input current through the first and second input terminals of the driver circuit. A variable current circuit is coupled between the first and second input terminals of the driver circuit and coupled to the input current sense circuit. The variable current circuit is coupled to conduct a bleeder current between the first and second input terminals in response to the bleeder on/off signal. A current scaling circuit is coupled to the variable current circuit to output a current scale signal which is received by the variable current circuit in response to a shutdown signal. The shutdown signal is representative of a conduction angle.

Variable bleeder circuit

A frequency determination circuit includes a positive crossing sense circuit coupled to receive an input voltage to sense a positive crossing of an input voltage. A validation circuit is coupled to the positive crossing sense circuit to validate a previous zero crossing and the positive crossing of the input voltage after the positive crossing of the of the input voltage has occurred. A measurement circuit is coupled to the positive crossing sense circuit and the validation circuit to count a time between positive crossing pulses of the input voltage. The measurement circuit is coupled to output a frequency signal that is representative of a frequency of the input voltage in response to the time between the positive crossing pulses of the input voltage.

Input frequency measurement

A bleeder circuit emulator for use in a power converter to compensate and increase the current demand from the Triac dimmer above its holding current. The circuit includes an input voltage modifier and a leading edge dimming detection circuit. The input voltage modifier receives an input voltage signal that is representative of a magnitude of an input voltage of the power converter and selectively provides a modified input voltage signal to an input of a controller in response to receiving a control signal. The modified input voltage signal is representative of a value that is less than the magnitude of the input voltage. The leading edge dimming detection circuit generates the control signal to engage the input voltage modifier to generate the modified input voltage signal in response to detecting leading edge dimming at an input of the power converter.

Bleeder circuit emulator for a power converter

A circuit to be utilized for an LED driver bleeder activation. The circuit comprises a circuit block for timing a duration of any removed portion of a rectified line signal. The input of the circuit to be coupled to receive the phase controlled rectified line signal through a voltage divider. Comparing the divided rectified line signal with a threshold voltage and output a comparison result. A timer coupled to the comparator and responsive to the comparison result to time the duration of the removed portion of the rectified line signal and activate the bleeder activation circuitry to turn on the switching element of the bleeder to sink a controlled current from the input line.

Dimmer detector for bleeder circuit activation

A bleeder circuit for use in a power supply of a lighting system includes a first terminal to be coupled to a first input of the power supply. A second terminal is to be coupled to a second input of the power supply. An edge detection circuit is coupled between the first and second terminals of the bleeder circuit. The edge detection circuit is coupled to output an edge detection signal in response to an input signal between the first and second inputs. A variable current circuit is coupled to the edge detection circuit and coupled between the first and second terminals of the bleeder circuit. The variable current circuit is coupled to conduct a bleeder current between the first and second terminals of the bleeder circuit in response to the edge detection signal.

Bleeder circuit for use in a power supply

A light emitting diode (LED) dimming module includes an energy storage circuit, a load interface circuit, and a switch circuit. The energy storage circuit provides a substantially continuous current in response to a converter current. The load interface circuit provides a modulated load current in response to the continuous current. The switch circuit, which is operatively coupled to the load interface circuit, switches in accordance with a duty cycle. The modulated load current is based on the duty cycle.

LED dimming circuit for switched dimming

A bleeder circuit for use in a power converter of a lighting system includes a current sense circuit coupled between first and second terminals of an input of a driver circuit to be coupled to drive a load. The current sense circuit is coupled to output a current sense signal in response to an input current through an input of the power converter coupled to the input of the driver circuit. An edge detection circuit is coupled between the first and second terminals to output an edge detection signal in response to an input signal between the first and second terminals. A variable current circuit is coupled between the first and second terminals to conduct a bleeder current between the first and second terminals in response to current sense signal and further in response to the edge detection signal.

Bleeder circuit having current sense with edge detection

A power converter includes dimmer circuit, a rectifier circuit, and a thyristor damper circuit. The dimmer circuit provides a dimmer voltage in response to an input voltage. The rectifier circuit provides a rectified voltage in response to the dimmer voltage. The thyristor damper circuit dampens an input current associated with the rectified voltage based on the input current and ceases dampening the rectified voltage based on the rectified voltage.

Damper circuit for switched dimming

Enhanced active preload circuits for an LED driver implementing phase-angle dimming are disclosed. The enhanced active preload circuits may be used with any type of phase-angle control dimmer that either controls the leading edge or trailing edge of the line voltage cycle. In one example, the enhanced active preload circuitry may be used with an isolated or non-isolated LED driver converter having a Triac leading edge phase-angle control dimmer by directly sensing (e.g., by sensing the dimming level using an output/load voltage signal or output/load current signal) or indirectly sensing (e.g., by sensing a signal of output or bias winding) the Triac conduction angle. The enhanced active preload circuitry may advantageously improve performance of the LED driver by extending the dimming ratio at deep dimming and by adjusting the preload sinking current in response to a preload control signal.

Enhanced active preload for high performance LED driver with extended dimming

A feedback circuit for a power converter (e.g., a non-isolated converter) is disclosed. The feedback circuit may include a sense circuit coupled to receive an output current of the converter. A sense voltage may be generated across the sense circuit and a voltage-to-current converter may be used to convert the sensed voltage into a feedback signal representative of the output current. The voltage-to-current converter may include a variable shunt regulator, resistor, and transistor. A voltage across the shunt regulator may change in response to a change in voltage across the sense circuit, and the feedback signal may change in response to a change in the voltage across the shunt regulator. A controller may be coupled to receive the feedback signal from the feedback circuit and may control switching of a power switch to regulate the output current based at least in part on the feedback signal.

Feedback circuit for non-isolated power converter

A circuit includes a switching power converter and a load current management circuit. The switching power converter provides a first current that varies between a first current value and a second current value in response to a dimming control signal. The load current management circuit provides a second current that varies between the second current value and a third current value in response to the dimming control signal. The second current varies in accordance with the first current. For example, the second current increases as the first current decreases and the second current decreases as the first current increases. In one example, the second current value corresponds to a required minimum load current for the power converter to regulate an output voltage.

Growing community of inventors

San Jose, CA, United States of America

Christian Pura Angeles