A vehicle speed sensor and negative voltage anti-interference communication system

Abstract

The invention discloses a vehicle speed sensor and a negative voltage anti-interference communication system. The negative voltage anti-interference communication system includes a signal emission module and a signal reception module. The signal reception module includes a power supply module. The first end of the power supply module is connected with an externally connected power supply, the second end of the power supply module is connected with an anode of a first diode, and a cathode of the first diode is connected with the ground. Signals emitted from the signal emission module are low-level zero crossing negative-voltage square wave pulses, and the low level of the low-level zero crossing negative-voltage square wave pulses is less than 0V. The signal reception module converts the low-level zero crossing negative-voltage square wave pulses into sampling level square wave pulses, the low level of the sampling level square wave pulses is 0V, and the high level of the sampling level square wave pulses is smaller than the high level of the low-level zero crossing negative-voltage square wave pulses. In this way, the low-level voltages across a signal line are lowered under a ground wire for communication, signal sampling will not be affected, and the anti-interference capability is guaranteed.

Description

technical field [0001] The invention relates to the communication field, in particular to a negative voltage anti-interference communication system. Background technique [0002] With the development of modern electronic technology, the automation level of automobiles, machine tools and chemical equipment is getting higher and higher. These devices are inseparable from the use of a large number of sensors and control switches. Therefore, signal communication is the soul of automatic control of these devices . In signal communication, the accuracy of the signal must be involved, which requires the communication signal to have anti-interference ability. [0003] At present, people widely use the differential signal processing method to improve the anti-interference ability of the control system, but this method has many shortcomings, such as the need to increase a large number of hardware facilities, and the communication line must use shielded wire or twisted pair, which inc...

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Problems solved by technology

However, it is almost impossible to use differential signal processing in the sending part and the execution part, and it is not realistic to use shielded wires or twisted pairs between the sending part, the main control system and the execution part. At the same time, the differential signal processing method It is also difficult to solve the problem of signal communication failure and hardware damage caused by the zero drift of the ground wire in the system

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