DIY Electronic Kit for Motorcycle Burglar Alarm

Description: 

K is the merrcury conductive switch, and S is the power switch linked with the car key. After the car stops properly, put the switch in the 'OFF' position, and then pull out the key. At this time, the two contacts in the merrcury conductive switch K are disconnected, and the '2' pin of the input terminal U1A is at a low level, so the '3' pin outputs a low level, the diode VD2 is turned off, and the transistor VT1 and the other diode VD3 are also turned off. The input pin '6' of U1B is low level, so the output pin '4' outputs low level, transistors VT3 and VT4 are turned off, and alarm horn B does not sound. If someone moves the car, it will inevitably cause vibration, so that the two contacts in the merrcury conductive switch K will be instantly closed, VD1 will be turned on, and both input terminals of U1A will be at h