On-Bright Electronics (Shanghai) Co., Ltd.

Controller and method for a power converter. For example, a controller for a power converter includes: a first drive signal generator configured to generate a first drive signal to turn off a first transistor at a first time and turn on the first transistor at a second time, the first transistor being configured to receive an input voltage and related to a primary winding coupled to an auxiliary winding and a secondary winding, the secondary winding being related to an output voltage, the second time being later than the first time; a second drive signal generator configured to generate a second drive signal to turn on a second transistor at a third time, the second transistor being coupled to the first transistor and related to the primary winding, the third time being later than the first time and being earlier than the second time.

DC-to-DC converter for multiport charging system and method thereof. For example, a DC-to-DC converter for a multiport charging system, the multiport charging system including a plurality of output ports that correspond to a plurality of DC-to-DC converters respectively, the plurality of DC-to-DC converters including the DC-to-DC converter, the plurality of output ports including a first output port that corresponds to the DC-to-DC converter, the DC-to-DC converter including: a load detector configured to: detect whether the first output port that corresponds to the DC-to-DC converter is connected to any load; and among the plurality of output ports, determine a first number of one or more output ports that are connected to one or more loads respectively; and a generator configured to: if the first output port that corresponds to the DC-to-DC converter is connected to a load, generate a first voltage as an output voltage for the first output port.

System and method for controlling synchronous rectification. For example, a system for controlling synchronous rectification, the system comprising: a first controller terminal configured to receive a first voltage; and a second controller terminal biased to a second voltage; wherein the system is further configured to: if a voltage difference from the first controller terminal to the second controller terminal satisfies one or more first conditions, generate a first current to flow through the first controller terminal; and if the voltage difference from the first controller terminal to the second controller terminal satisfies one or more second conditions, generate a second current to flow through the second controller terminal; wherein: the voltage difference from the first controller terminal to the second controller terminal is equal to the first voltage minus the second voltage; the one or more first conditions and the one or more second conditions are different.

System and method for controlling one or more light emitting diodes. For example, the system includes: a power supply controller configured to receive a cathode voltage from a cathode of a diode, the diode including an anode configured to receive a rectified voltage generated by a rectifying bridge, the power supply controller being further configured to generate a first signal based at least in part on the cathode voltage; and a driver configured to receive the first signal and generate a second signal based at least in part on the first signal, the driver being further configured to output the second signal to a gate terminal of a transistor, the transistor including a source terminal coupled to the driver and a first resistor, the transistor further including a drain terminal coupled to the one or more light emitting diodes and an output capacitor connected to the cathode of the diode.

System and method for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer. For example, the system for controlling a bleeder current to increase a power factor of an LED lighting system without any TRIAC dimmer includes: a first current controller configured to receive a rectified voltage generated by a rectifier that directly receives an AC input voltage without through any TRIAC dimmer; and a second current controller configured to: control a light emitting diode current flowing through one or more light emitting diodes that receive the rectified voltage not clipped by any TRIAC dimmer; and generate a sensing voltage based at least in part upon the light emitting diode current, the sensing voltage representing the light emitting diode current in magnitude.

USB controller for one or more USB connectors and method thereof. For example, a USB controller for one or more USB connectors includes: a detector configured to receive a first input signal from a first pin of a first USB connector and receive a second input signal from a second pin of the first USB connector and generate a detection signal based at least in part on the first input signal and the second input signal; a logic controller configured to receive the detection signal and generate a first control signal and a second control signal based at least in part on the detection signal; a driver configured to receive the first control signal, generate a drive signal based at least in part on the first control signal, and output the drive signal to a first transistor terminal of a transistor.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current generator configured to generate a first current flowing through one or more light emitting diodes. The one or more light emitting diodes are configured to receive a rectified voltage generated by a rectifying bridge coupled to a TRIAC dimmer. Additionally, the system includes a bleeder configured to receive the rectified voltage, and a controller configured to receive a sensing voltage from the current generator and output a control signal to the bleeder. The sensing voltage indicates a magnitude of the first current.

USB charging system and method. For example, a USB charging system includes: a first AC-to-DC conversion unit configured to generate a first voltage and a first current; a second AC-to-DC conversion unit configured to generate a second voltage and a second current; a first USB output port corresponding to the first AC-to-DC conversion unit; a second USB output port corresponding to the second AC-to-DC conversion unit; a switch connected to the first AC-to-DC conversion unit and the second AC-to-DC conversion unit; and a control chip connected to the first AC-to-DC conversion unit and the second AC-to-DC conversion unit and configured to open the switch and close the switch; wherein the control chip is further configured to: determine whether the first USB output port is connected to a load device and whether the second USB output port is connected to a load device.

Charge pump and method therefor. For example, a charge pump for converting an input voltage to an output voltage includes: a first capacitor connected between a first terminal and a second terminal; a second capacitor connected between the second terminal and a third terminal; a first transistor including a first drain, a first source, and a first gate, the first drain being connected to an input terminal configured to receive the input voltage; a second transistor including a second drain, a second source, and a second gate; a third transistor; a fourth transistor; and an internal circuit configured to perform a self-detection process by determining whether or not at least one defect has been detected for at least one component selected from a group consisting of the first capacitor, the second capacitor, the first transistor, the second transistor, the third transistor, and the fourth transistor.

System and method for controlling one or more light emitting diodes. For example, the system for controlling one or more light emitting diodes includes a current regulation circuit coupled to a cathode of one or more light emitting diodes. The one or more light emitting diodes include the cathode and an anode configured to receive a rectified voltage. Additionally, the system includes a control circuit coupled to the cathode of the one or more light emitting diodes. The control circuit is configured to receive a first voltage from the cathode of the one or more light emitting diodes, compare a second voltage and a threshold voltage, and generate a control signal based at least in part on the second voltage and the threshold voltage. The second voltage indicates a magnitude of the first voltage.