This light-emitting element drive control device (100) comprises: a drive logic unit (113) which performs a drive control of a switch output stage (N1, D1, L1) for dropping an input voltage (VIN) to an output voltage (VOUT) and supplying a light-emitting element therewith; a charge-pump power supply unit (a) which generates a step-up voltage (CP) higher than the input voltage (VIN); and a current detecting comparator (114) which receives a supply of the step-up voltage (CP) and the output voltage (VOUT) as power supply voltages, and generates control signals (SET, RST) for the drive logic unit (113) by directly comparing a current detection signal (Vsns) corresponding to an inductor current (IL) of the switch output stage with a peak detection value (Vsns_pk) and a bottom detection value (Vsns_bt).

An encapsulated LED switch that incorporates a MOSFET power drivers, high current transistors, or other suitable power drivers in a PCB that attaches to the LED switch such that a low power LED switch controls the output of a high-power driver. The selected power driver PCB can be adapted to different load requirements by making simple changes. The PCB's can be interchanged to provide for a predetermined output power required for a particular application. In addition, the wire gauge size of the wires attached to the MOSFET power driver PCB can also be varied to match intended load requirements. For applications in which the LED switch is used in hostile environments, such as marine applications, the LED switch and its associated power driver PCB are encapsulated to protect the circuitry from environmental factors such as high humidity, salt water, etc.

A system is created for an efficient dimming LED lighting system, and comprising a voltage source, an electronic switch controlled by a pulse width modulation, PWM, driving signal and an LED lighting module connected in series. The LED comprises an LED group and a constant current drive circuit to drive a constant current through the LED group. The voltage source and a bypass branch, which is connected in parallel with the electronic switch, is adapted such that when the electronic switch is open, a power delivered to the constant current drive circuit is sufficient to maintain operation of the constant current drive circuit, ensuring capability for a deep dimming

A system is created for an efficient dimming LED lighting system, and comprising a voltage source, an electronic switch controlled by a pulse width modulation, PWM, driving signal and an LED lighting module connected in series. The LED comprises an LED group and a constant current drive circuit to drive a constant current through the LED group. The voltage source and a bypass branch, which is connected in parallel with the electronic switch, is adapted such that when the electronic switch is open, a power delivered to the constant current drive circuit is sufficient to maintain operation of the constant current drive circuit, ensuring capability for a deep dimming

A drive circuit that includes a switching circuit switching between a first state and a second state to cause a light-emitting element to perform pulse oscillation, and a direct current adjustment circuit. In the first state, light is emitted from a light-emitting element by supplying the light-emitting element with a current having a magnitude equal to or greater than a threshold current enabling the light-emitting element to emit light having an output equal to or greater than a predetermined output. In the second state, the magnitude of the current supplied to the light-emitting element is less than the threshold current. The direct current adjustment circuit supplies, to the light-emitting element, a bias current within a range less than the threshold current of the light-emitting element in the second state. The bias current has a magnitude corresponding to a magnitude of undershoot occurring at a falling edge of the pulse oscillation.

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 comparasion 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.

A multi-channel constant current circuit and a lighting device are provided. The multi-channel constant current circuit is used to drive UVC LED to emit light, and includes a constant voltage circuit and a first number of linear constant current diodes. The constant voltage circuit includes a power input terminal, a power output terminal and a voltage regulation sub-circuit. The power input terminal is connected to the power output terminal through the voltage regulation sub-circuit, each of the linear constant current diodes is connected to the power output terminal, the linear constant current diode is used to connect a second number of UVC LEDs and keeps a working current of each UVC LED, and the voltage regulation sub-circuit is used for a constant output voltage.

A multi-channel constant current circuit and a lighting device are provided. The multi-channel constant current circuit is used to drive UVC LED to emit light, and includes a constant voltage circuit and a first number of linear constant current diodes. The constant voltage circuit includes a power input terminal, a power output terminal and a voltage regulation sub-circuit. The power input terminal is connected to the power output terminal through the voltage regulation sub-circuit, each of the linear constant current diodes is connected to the power output terminal, the linear constant current diode is used to connect a second number of UVC LEDs and keeps a working current of each UVC LED, and the voltage regulation sub-circuit is used for a constant output voltage.

A MOSFET circuit clamps a MOSFET gate voltage (either directly or via a gate control circuit) when the source voltage exceeds a threshold level, for example in response to a voltage surge event between the source and drain. In particular, the gate is held at a voltage relative to the source, to turn off the first MOSFET during such a surge event, but not during normal operation. This provides automatic protection against unwanted increases in the input voltage, especially when the MOSFET was in its on state during the switching. A threshold circuit is connected between a gate (or gate control node) and a reference voltage. When the voltage at the source exceeds a voltage threshold level, it conduct a unidirectional circuit component (D18) between the source and gate (or gate control node), and the threshold circuit.

A MOSFET circuit clamps a MOSFET gate voltage (either directly or via a gate control circuit) when the source voltage exceeds a threshold level, for example in response to a voltage surge event between the source and drain. In particular, the gate is held at a voltage relative to the source, to turn off the first MOSFET during such a surge event, but not during normal operation. This provides automatic protection against unwanted increases in the input voltage, especially when the MOSFET was in its on state during the switching. A threshold circuit is connected between a gate (or gate control node) and a reference voltage. When the voltage at the source exceeds a voltage threshold level, it conduct a unidirectional circuit component (D18) between the source and gate (or gate control node), and the threshold circuit.