Photoelectric signal sampling circuit based on digital resistor and configuration method thereof

Abstract

The invention provides a photoelectric signal sampling circuit based on a digital resistor. The photoelectric signal sampling circuit comprises an infrared receiving unit I and an infrared receiving unit II which are respectively coupled between a first reference voltage and a power ground, wherein a first comparator of which an in-phase input end is coupled with a voltage output end of the infrared receiving unit I, a non-inverting input end of the first comparator is coupled with a first voltage output end of the infrared receiving unit, a non-inverting input end of the second comparator is coupled with a second voltage output end of the infrared receiving unit, the reference voltage output unit is respectively coupled with inverting input ends of the first comparator and the second comparator, and the reference voltage output unit comprises a voltage division circuit and a following comparator which are coupled with a reference voltage source, and an MCU (Microprogrammed Control Unit) coupled with the voltage division circuit; and the voltage division circuit comprises a voltage division resistor and a digital potentiometer which are connected in series. According to the circuit, an actual output voltage of the infrared receiving unit is sampled, a resistance value of the digital potentiometer is set through calculation, then the loop partial voltage is adjusted, the reference voltage can be accurately set, and the sampling result is more stable and accurate.

Description

technical field [0001] The invention relates to the technical field of signal sampling, in particular to a digital resistor-based photoelectric signal sampling circuit and a configuration method thereof. Background technique [0002] In smart watt-hour meters or gas diaphragm meters, it is usually installed on the metering shaft as attached figure 1 Black and white turntable shown. The signal acquisition end is equipped with an optical transceiver device. The transmitting tube regularly emits optical signals. The optical signal is irradiated on the black and white turntable. The black absorbs the optical signal, and the white reflects the optical signal, which is reflected to the optical receiving tube. After the signal loop control, the chip detects the high and low changes. The level signal, and then judge the number of rotations of the disc. [0003] When the above-mentioned device is running, under some conditions, it will cause interference to the sampling, such as th...

AI Technical Summary

Problems solved by technology

However, some instruments may have uneven distribution of signals (such as image 3 shown), at this time, the detection signal period needs to be shortened, resulting in an increase in overall power consumption

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