Current measuring circuit and method for LED driving power supply

Abstract

The present invention proposes a current measuring circuit and method for an LED drive power supply. The current measuring circuit includes a current limiting resistor, a current measuring resistor, a comparator, a logic circuit, a driving circuit and a load, and also includes a control circuit and a configuration resistor. One end of the resistor and one end of the current-measuring resistor are both connected to the input power supply, the other end of the current-limiting resistor is connected to the first input end of the comparator and the fourth input end of the control circuit, and the other end of the current-measuring resistor is connected to the other input end of the comparator and the output end of the load , the output terminal of the comparator is connected to the second input terminal of the control circuit through the logic circuit, the input terminal of the load is connected to the output terminal of the drive circuit, the first input terminal of the control circuit inputs the control voltage signal, and the third input terminal of the control circuit is connected to one terminal of the configuration resistor, The output terminal of the control circuit is connected with the input terminal of the driving circuit. The current measuring circuit can realize the accurate current measuring feedback function, is applied to different load applications, improves the generality of the current measuring circuit, and reduces the cost.

Description

technical field [0001] The invention relates to the technical field of LED driving power supply, in particular to a novel current measuring circuit and method for LED driving power supply. Background technique [0002] LED drive power supply refers to the power converter that converts the power supply (such as high-voltage industrial frequency AC or mains power, low-voltage high-frequency AC such as the output of electronic transformers, etc.) into a specific voltage and current to drive LED lighting equipment or devices to emit light. That is to say, the power supply is converted to the rated power suitable for the operation of lighting equipment or devices through devices such as transformers. In order to ensure the safe use of the LED drive power supply, a control circuit is generally configured in the LED drive power supply, and the control circuit controls the LED drive power supply according to the corresponding current measurement feedback results. The traditional cu...

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Problems solved by technology

[0003] The present invention aims at the problem that the current measurement circuit of the existing LED drive power supply cannot be applied to different load ranges due to the use of a constant current source, and the existing current measurement circuit has a single index and poor versatility, thus resulting in high repeated design costs. A new type of current measurement circuit for LED drive power supply. Through the reasonable configuration of resistance and multi-input control circuit, the circuit realizes the accurate current measurement and feedback function, and at the same time realizes the application of current measurement circuit to different load applications, and improves the Improve the versatility of the current measurement circuit, reduce the design cycle and cost

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