Abstract: A power conversion circuit and a method thereof, wherein the power conversion circuit includes a first grid interface and a second grid interface coupled to an AC power source, a power harvesting module, a sampling module and a switching module. The power harvesting module is coupled to the first grid interface, and the power harvesting module includes a first diode and a first charging capacitor coupled to the first diode. The power harvesting module receives the AC power source from the first grid interface to generate an output voltage. The switching module includes a switch component controlled by the sampling module. The sampling module is coupled to the power harvesting module and acquires a sampling voltage. The sampling module controls the switch component to be turned off during at least a period of time within positive half cycles of the AC power source.

Abstract: The present invention discloses a control circuit, a LED driving system, and a LED driving method. The control circuit receives a feedback signal from the power converter and generate a ZCD pulse signal accordingly, indicating one or more moments when the feedback signal decreases to zero, and receives a dimming signal and generate a minimum turn-off time signal accordingly, indicating the moment when a minimum turn-off time is passed. The control circuit generates a first turn-on signal according to the ZCD pulse signal and the minimum turn-off time signal to control a switching device within the power converter to turn on when the feedback signal decreases to zero and the minimum turn-off time is passed.

Abstract: A dimming control circuit, driving device and control method thereof, the dimming control circuit comprising a dimmer, a driving device coupled to the dimmer and controlling a load on the basis of a dimming level reference of the dimmer, and a bleeder supplying power to the dimmer, the driving device including a power switch coupled to the load, wherein a duty ratio of a driving voltage on the power switch is adjusted in accordance with the dimming level reference to control an operating current of the load.

Abstract: A low-pass filter, a switching control circuit, a driving system, a chip and methods are disclosed. The low-pass filter performs digital differential-integral process on a voltage of an acquired analog signal and a predefined reference voltage to generate differential-integral signals, accumulates a count of the differential-integral signals, and convert the result to an analog signal. By performing differential-integral process accumulating a count of the differential-integral signals, a low-pass filtered signal is obtained in a way that solves the problem of low integrity of circuits in conventional driving systems, reduces the complexity of external circuits for such driving systems and increases their circuit stability.

Abstract: A control circuit and method for a bleeder, a chip, and a driver system. The bleeder control circuit is connected to a dimmer detector used for detecting the presence or absence of a dimmer and a type of the dimmer. The control circuit of the bleeder is used to receive a detection signal outputted by the dimmer detector, and generate a control signal for the bleeder according to the detection signal, the control signal is used to control an operating state of the bleeder. The application correspondingly generates a control signal for a bleeder according to a detection signal indicating the presence or absence of a dimmer and the type of the dimmer so as to control the bleeder to operate only at a given phase interval, and may thereby reduce the power consumption of the bleeder when ensuring the stable operation of a dimmer.

Abstract: The present invention discloses a multi-phase power supply dynamic response control circuit and a control method. When a rapid rise of the load is detected, an output PWM signal is temporarily adjusted to enter a second operation mode from a first operation mode to supplement energy to the load and prevent the output voltage from decreasing. The present invention requires little modification to the existing circuit, and adopts simple, explicit and efficient detection method, realizing rapid dynamic response by providing sufficient energy for the load when the load current is suddenly increased.

Abstract: The present disclosure provides a leakage protection circuit, a method and a drive device. The leakage protection circuit is used for being electrically connected with the power supply line of a load, and may be configured to sample the power supply line at intervals, detect the voltage of the sampled electrical signals to determine whether the voltage of the AC input power is divided, and provide leakage protection based on the determined result. The present disclosure can prevent human from electric shock through sampling the electric signals from the power supply line at intervals and performing voltage detection and comparison to determine whether the voltage of the accessed AC input power is divided, when the voltage of the accessed AC input power is determined to be divided, the power supply line will be controlled in non-conductive state.

Abstract: Provided are a TRIAC dimmer detection circuit, chip and method, and an LED driving chip and system. A bus voltage reflecting signal is received, and a TRIAC dimmer detection signal is generated according to the bus voltage reflecting signal, a first reference voltage and a second reference voltage, the dimmer detection signal being used to detect whether a dimmer exists and to determine the type of the dimmer. The TRIAC dimmer detection circuit, chip and method, and the LED driving chip and system consistent with the present invention can detect whether a TRIAC dimmer is contained in an LED illuminating system, so as to determine a working state of a bleeder, thereby reducing the power consumption of the entire LED illuminating system and improving the efficiency thereof.

Abstract: Provided are a TRIAC dimmer detection circuit, chip and method, and an LED driving chip and system. A bus voltage reflecting signal is received, and a TRIAC dimmer detection signal is generated according to the bus voltage reflecting signal, a first reference voltage and a second reference voltage, the dimmer detection signal being used to detect whether a dimmer exists and to determine the type of the dimmer. The TRIAC dimmer detection circuit, chip and method, and the LED driving chip and system consistent with the present invention can detect whether a TRIAC dimmer is contained in an LED illuminating system, so as to determine a working state of a bleeder, thereby reducing the power consumption of the entire LED illuminating system and improving the efficiency thereof.

Abstract: The present disclosure provides a line voltage compensation circuit, an LED drive system and a drive method. The line voltage compensation circuit is configured to receive signal reflecting bus voltage and output line voltage compensation signal based on the received signal reflecting bus voltage, a preset baseline voltage and at least one reference voltage, wherein the line voltage compensation signal has a multi-segment linear relationship with the received signal reflecting bus voltage. In the technical solution provided by the present application, the linear relationship between the feedback voltage of the LED load and the built-in baseline voltage is adjusted based on at least one preset threshold to output segment-based line voltage compensation signal. Compared with the line voltage compensation technology with a single slope, better input voltage line regulation and better LED current line regulation can be obtained by adopting the technical solution provided by the present application.

Abstract: The present invention discloses a position-sensorless control method for a brushless motor, the method including: turning off a first driving voltage of a first phase coil, and within detection time, detecting a back electromotive force of the first phase coil; determining a reference phase and a cycle of a second driving voltage according to the back electromotive force; determining a pulse width modulation signal according to the reference phase and the cycle; and determining to provide the second driving voltage for the brushless motor according to the pulse width modulation signal, the second driving voltage being used to drive the brushless motor. The present invention effectively reduces the cost, decreases implementation difficulty and increases system performance and reliability.

Abstract: A TRIAC dimmable light-emitting diode (LED) driver circuit is disclosed, compromising: An alternating-current (AC) voltage connected to a rectifier bridge; An LED load, which is connected to an inductor or a transformer, a power MOS transistor, a low voltage MOS transistor and a current sensing resistor. The LED driver also compromises: a peak current comparator which is used to compare the voltage between a current sensing resistor and a reference voltage; a maximum on-time timer, which is used to detect the on time of the low voltage MOS transistor. When the voltage on the current sensing resistor is higher than the reference voltage or the on time of the low voltage MOS transistor reaches the preset time of the maximum on-time timer, the low voltage MOS transistor is turned off.

Abstract: A current ripple canceling light-emitting diode (LED) driver is disclosed. The input current source contains a current ripple. The LED load is connected to the drain of a power switch. The source of the power switch is connected to a current sensing resistor. The gate of the power switch is connected to the output of an operational amplifier. The operational amplifier compares the voltage signal across the current sensing resistor with a dynamic reference voltage. The dynamic reference voltage is adjusted according to the gate or drain voltage of the power switch. The LED load current is controlled to be a nearly no ripple DC current.

Abstract: A TRIAC dimmable light-emitting diode (LED) driver circuit is disclosed, compromising: An alternating-current (AC) voltage connected to a rectifier bridge; An LED load, which is connected to an inductor or a transformer, a power MOS transistor, a low voltage MOS transistor and a current sensing resistor. The LED driver also compromises: a peak current comparator which is used to compare the voltage between a current sensing resistor and a reference voltage; a maximum on-time timer, which is used to detect the on time of the low voltage MOS transistor. When the voltage on the current sensing resistor is higher than the reference voltage or the on time of the low voltage MOS transistor reaches the preset time of the maximum on-time timer, the low voltage MOS transistor is turned off.

Abstract: A current ripple canceling light-emitting diode (LED) driver is disclosed. The input current source contains a current ripple. The LED load is connected to the drain of a power switch. The source of the power switch is connected to a current sensing resistor. The gate of the power switch is connected to the output of an operational amplifier. The operational amplifier compares the voltage signal across the current sensing resistor with a dynamic reference voltage. The dynamic reference voltage is adjusted according to the gate or drain voltage of the power switch. The LED load current is controlled to be a nearly no ripple DC current.

Abstract: An average linear light-emitting diode (LED) driver circuit is disclosed. An inputting alternating-current (AC) voltage is connected to a rectifier bridge. An LED load is paralleled with a filtering capacitor and connected to a power switch. A compensation network and a voltage feedback network are included. When the output voltage of the rectifier bridge is higher than the voltage of the filtering capacitor, the drain voltage of the power switch is increased. The voltage feedback network decreases or turns off the current in the power switch. The compensation network controls the average current in the power switch to be equal to the desired LED load current. The average linear LED driver circuit intelligently controls the driver current, reduces the system power loss and increases the system efficiency. The LED driver maintains high conversion efficiency, especially under wide input voltage conditions.