Load voltage compensation circuit for light-emitting diode (LED) driving

Abstract

The invention discloses a circuit, and particularly discloses a load voltage compensation circuit for light-emitting diode (LED) driving. The load voltage compensation circuit comprises a load voltage detection module, a sampling hold module, a load voltage compensation module, a current detection module, a degaussing detection module, a control drive module, a transformer, a switch tube, a sampling resistor and a divider resistor, wherein the load voltage detection module, the sampling hold module and the load voltage compensation module are sequentially connected with one another in series; an output end of the load voltage compensation module is connected with the control drive module; a feedback detection end is also led out from the middle of the divider resistor by the circuit, and is simultaneously connected with input ends of the load voltage detection module and the degaussing detection module; the output ends of the degaussing detection module and the current detection module are both connected with the control drive module; the control drive module is connected with the switch tube; the switch tube is connected with the transformer through the sampling resistor; and the transformer is connected with the divider resistor in parallel. The accuracy of output current of the load voltage compensation circuit is high; an auxiliary winding of the transformer is not needed; a peripheral circuit is simplified; and the cost is reduced.

Description

technical field [0001] The invention relates to a compensation circuit, in particular to a load voltage compensation circuit for LED driving. Background technique [0002] The critical conduction control method is widely used in the LED drive circuit to achieve constant current output, and the zero-crossing detection module detects the end time of transformer degaussing. According to the electrical characteristics, LED drive circuits can be divided into isolated LED drive circuits and non-isolated LED drive circuits. Due to insulation, heat dissipation problems and historical problems in power supply technology, non-isolated drive circuits have a wide range of applications. At present, the existing non-isolated LED drive circuit generally has two configuration schemes, which are as follows: [0003] The first is the traditional non-isolated LED driver circuit, such as figure 1 As shown, the transformer, current detection module, degaussing detection module, control and dri...

AI Technical Summary

Problems solved by technology

In the prior art, it is necessary to detect the load voltage through the auxiliary winding (La), and the design of the auxiliary winding increases the cost of the circuit

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