A processing circuit of a photoelectric liquid level meter

Abstract

The invention relates to a processing circuit of a photoelectric liquid level meter. It includes a power supply, an adjustable power supply, an infrared luminous tube array, a luminous tube control unit, an infrared receiving tube array, a multi-channel analog switch, an A / D converter and a processor. , the multi-channel analog switch and the adjustable power supply are turned on, the output terminals of the processor and the multi-channel analog switch are conducted through the A / D converter; the output terminal of the luminous tube control unit and the input terminal of the infrared luminous tube array are all turned on, the infrared luminescent tube array is connected to the adjustable power supply; each branch of the input end of the multi-channel analog switch and the output end of the infrared receiving tube array is turned on. The circuit has low power consumption, wide power supply range, super error correction capability for sensor data, and improves the working performance of the instrument and enhances the reliability of the instrument.

Description

technical field [0001] The invention belongs to the technical field of liquid level measurement, and relates to a processing circuit of a photoelectric liquid level meter. Background technique [0002] Steel strip liquid level gauges have been widely used in the measurement of oil storage tanks, and the steel strip liquid level gauges use infrared photoelectric sensors most. The infrared photoelectric sensor generally consists of a group of infrared light-emitting tubes, a set of infrared receiving tubes, and a light-transmitting stainless steel Gray code belt or Gray code disc sandwiched between the light-emitting tubes and the receiving tubes and linked to the liquid level. The positions of the light-emitting tubes and the receiving tubes are One to one correspondence. The usual implementation method is to connect all the light-emitting tubes in series and then drive them to emit light by a constant current source. After the receiving tube outputs the level to the gate ci...

AI Technical Summary

Problems solved by technology

This method has the following problems: First, it is difficult to select a safety barrier

Since the logic level identification requirements of the gate circuit or the IO of the CPU must be 0.7Vcc, and the logic judgment at the (0.3~0.7) Vcc voltage input terminal is uncertain, this requires infrared light emitting and receiving logic The matching is very strict, otherwise the data of the level gauge will jump

The third is the large amount of maintenance and long-term performance reduction

The long-term work of the instrument on site reduces the performance of the light-emitting receiving tube, and the stains on the light-transmitting code tape and the influence of the operating position deviation will cause the logic level to be unsatisfactory and cause data errors, which will affect the instrument’s work and detection, and increase on-site maintenance. Work intensity of personnel

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