Inventronics (Hangzhou), Inc.

Inventronics (Hangzhou) Co., Ltd.

Inventronics, Inc.

Lijun Ren

Guichao Hua

Xiaoli Yao

Liang'an Ge

Xinke Wu

Liangan Ge

A multi-path constant current driving circuit. In the multi-path constant current driving circuit, a current sharing transformer (T, T, T, T(n&#x2212;1)) is provided in power supply circuits which are provided with adjacent rectifier and filter units (Z, Z, Z, Zn). A first winding of the current sharing transformer (T, T, T, T(n&#x2212;1)) is connected between a first terminal of a secondary winding of a first power supply circuit and the rectifier and filter unit (Z, Z, Z, Zn) of the first power supply circuit. A second winding of the current sharing transformer (T, T, T, T(n&#x2212;1)) is connected between a first terminal of a secondary winding of a second power supply circuit and the rectifier and filter unit (Z, Z, Z, Zn) of the second power supply circuit. In-phase current flows through the dotted terminal of the first winding and the synonym terminal of the second winding of the current sharing transformer (T, T, T, T(n&#x2212;1)). The current sharing transformer (T, T, T, T(n&#x2212;1)) is used for sharing the current between the power supply circuits which are provided with the adjacent rectifier and filter units (Z, Z, Z, Zn ). The driving circuit is provided with high current sharing efficiency, a small size and a low cost.

Multi-path constant current driving circuit

A constant-current Light Emitting Diode (LED) driver circuit is provided, and the circuit includes: an output voltage adjustable circuit and at least one path of LED load, wherein the output voltage adjustable circuit comprises: a switch converting main circuit, an output characteristic parameter sampling circuit, and an output voltage controller. The output voltage controller is used to adjust the output voltage of the switch converting main circuit according to the variation relationship between the sampling signal output by the output characteristic parameter sampling circuit and the output voltage, determine the adjustive direction of the output voltage magnitude of the switch converting main circuit according to the change of the sampling signal, adjust the magnitude of the output voltage of the switch converting main circuit according to the preset step, and finally make the output voltage equal to the voltage of one path of LED load with the highest voltage or the difference between the output voltage and the voltage of one path of LED load voltage with the highest voltage within the predetermined range. The present solution implements reducing the connection complexity and power dissipation on the base of controlling the multi-path constant-current LED.

Constant-current LED driver circuit and output voltage adjustable circuit and method thereof

A circuit to improve the power factor of a power supply at light load, the circuit including a rectifier bridge, a filter positioned before or after the rectifier bridge, a logic control and power drive circuit, a switching transistor, a light load detecting circuit configured to output a control signal to the logic control and power drive circuit which controls the switching transistor to conduct when a heavy load is experienced and to cut off when a light load is experienced, in order to control the working status of the filter capacitor, and a power factor correction circuit.

Circuit to improve light load power factor of power supply

A multi-path constant current drive circuit includes a DC/AC converter, a main transformer and at least two rectifying and filtering units. The main transformer includes at least one assistant side winding with a tap; together with the assistant side winding of the main transformer, each of the at least two rectifying and filtering units respectively forms a power supply loop; each power supply loop includes a first rectifying loop and a second rectifying loop, which are relatively used for the rectification of the positive and the negative half-cycle alternating voltage; a current-equalizing transformer is arranged between the adjacent first power supply loop and second power supply loop, the windings of the current-equalizing transformer are respectively in the rectifying loops contained in the first power supply loop and the second power supply loop, thus realizing the current equalization between the different rectifying loops in which the adjacent rectifying and filtering units are contained. The multi-path constant current drive circuit performs a good current equalization, and can reduce the volume of the current-equalizing transformer and decrease the cost.

A PWM dimming circuit for a LED load including a LED load connected to the main LED drive circuit, a current loop configured to measure output current from the LED load, a current loop regulation circuit connected to the current loop, a main control circuit configured to receive a signal from the current loop when the LED load produces an output current, and a PWM dimming controller configured to provide a signal to control the current loop regulation circuit and to make the current loop operate in a closed-loop mode when the LED load produces the output current and to provide a shutdown signal to the main control circuit when the LED load does not produce the output current. When the output current is detected, the main control circuit controls the main LED drive circuit to set its output current at a predetermined load current.

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Zhejiang, China

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