ANTI-INTERFERENCE SWITCH SIGNAL TRANSMISSION CIRCUIT

摘要

An anti-interference switch signal transmission circuit, in which a changeover contact is used at a signal terminal, wherein a normally closed contact is connected to DC−, a normally open contact is connected to DC+, and a common terminal is connected to a switch signal acquisition circuit. When no signal exists, DC− is connected to a positive input terminal of the switch signal acquisition circuit via the normally closed contact. Since a negative input terminal of the switch signal acquisition circuit is also connected to DC−, even if interference is caused, no false signal is generated. When a signal exists, the position of the changeover contact changes and DC+ is connected to DC− via the closed normally open contact through the switch signal acquisition circuit thus a loop is formed, so that the signal can be reflected. The interference problem is solved by connecting both the two terminals of the acquisition circuit to DC− when no signal exists.

主权项

1. An anti-interference switch signal transmission circuit, including a changeover contact, a negative terminal (DC−) of a DC power supply, a positive terminal (DC+) of the DC power supply, and a switch signal acquisition circuit;
wherein the changeover contact includes a normally open contact and a normally closed contact; wherein the changeover contact is controlled by a signal terminal to be collected; wherein a collection terminal of the switch signal acquisition circuit is connected to a switch signal to be collected; wherein one terminal of the switch signal acquisition circuit is linked with the positive terminal DC+ by the normally open contact, and the other terminal is connected to DC−; wherein one terminal of the switch signal acquisition circuit is linked with the negative terminal DC− by the normally closed contact, and the other terminal is connected to DC−; wherein when no switch signal occurs, the normally open contact open and the normally closed contact closed, the circuit level of the switch signal acquisition circuit is always in the negative DC power status; and wherein when there are switch signal, the normally closed contact open and the normally closed open contact closed, the positive terminal DC+ is connected to the negative terminal DC− via the closed normally open contact so as to form a loop, thus the switch signal acquisition circuit is ON.