Low-cost DC voltage isolation collection circuit

Abstract

The invention discloses and provides a low-cost DC voltage isolation collection circuit, and the circuit comprises a DC voltage input part, a resistor mode voltage reduction part, an isolation outputfeedback circuit, an operational amplifier differential input circuit, and an isolation voltage DC output part. The resistor mode voltage reduction part carries out the voltage reduction and limitingof the voltage of the output end of the DC voltage input part, and then inputs the voltage into an input end of the isolation output feedback circuit. The output end of the isolation output feedback circuit divides the voltage into an isolation output part and a feedback signal, and is connected with the operational amplifier differential input circuit and the isolation voltage DC output part. Theisolation voltage DC output part outputs a DC isolation voltage. Because two common optoelectronic isolation circuits and an operational amplifier circuit are employed and a corresponding feedback circuit is introduced, the circuit achieves the functions of DC voltage isolation and collection, and outputs a corresponding isolated DC voltage, wherein one way serves as input and the other way serves as the feedback. Therefore, the circuit is low in cost, and is simple.

Description

technical field

[0001] The invention relates to a DC voltage acquisition circuit, in particular to a low-cost DC voltage isolation acquisition circuit. Background technique

[0002] At present, there are mainly two types of DC voltage isolation acquisition circuits: (1) Linear optocoupler plus isolated DC-DC power supply. This solution is to isolate and transmit analog signals through linear optocoupler, and the isolated DC-DC provides power isolation for linear optocoupler. ; (2) DC-DC power supply composed of ADC dedicated chip, signal, and power isolation. This solution is to collect analog signals through a dedicated ADC chip, and output the corresponding analog voltage value through a digital isolation chip and power supply. The two kinds of DC voltage isolation acquisition circuits widely used at present, the former adopts linear optocoupler plus isolated power supply, and the latter adopts ADC dedicated chip, signal, and isolated power supply. Both of them have the de...

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