Wireless alarm circuit with multiple detection heads

The alarm separates the detection and alarm parts. One alarm can have multiple detection heads. The detection and alarm parts communicate using radio waves. It is divided into a wireless alarm receiving part and a wireless alarm detection transmitting part. The wireless alarm receiving part is mainly composed of a 315MHz wireless data receiving module, a decoding integrated circuit PT2272-M4, a monostable circuit and an audio generator. The circuit is shown in the figure below.

There are many detection circuits in the detection and transmission part of the wireless alarm.

(1) Transmitter circuit composed of photoresistor:

(2) Magnetic induction transmitting circuit:

(3) Fuse/fine wire launch circuit:

The wireless alarm circuit can be made by directly welding with a universal circuit board, eliminating the trouble of making a printed circuit board; after the circuit is connected, check it once and make sure there is no error before powering it on for testing. First, turn on the power of the receiving part, then turn on the power of one of the transmitting parts, and artificially make the detection transmitting part emit an alarm signal. If there is an alarm sound at the receiving end of the alarm, it means that the receiving part and the transmitting part of the detection circuit are working properly. After the detection transmitting part is debugged, debug the other two detection transmitting part circuits. After all the debugging is completed, it can be installed in an appropriate place for use.