Simple and practical electric vehicle anti-theft alarm circuit diagram

With the increasing awareness of environmental protection, electric vehicles have entered our homes in large numbers and become an indispensable means of transportation for some people. How to prevent electric vehicles from being stolen is a matter of great concern to car owners. For this reason, various types of electric vehicle anti-theft locks have emerged. However, electric vehicles are still being stolen frequently. Higher-end electric vehicle anti-theft locks are difficult to destroy in a short period of time, so thieves move the electric vehicles onto other vehicles and steal them. In this way, even the most advanced anti-theft locks are powerless. In view of this, we introduce to you the circuit diagram of an electric vehicle anti-theft alarm.

The transmitter part of the alarm is used to control the power supply of the transmitter circuit by relay K and thyristor VS. IC1 forms the alarm signal circuit. Transistor V and its peripheral components form a radio frequency oscillation circuit to emit alarm signals.

In the waiting state, switch S1 is turned on and SB1 is turned off (that is, the front lock is locked), K is in the released state, and the alarm transmitter does not work. When the front lock is opened (that is, SB1 is turned on), VS is triggered to conduct, K is closed, and the transmitter power is turned on. After SB1 is connected, the normally open point of K-2 will self-lock. At this time, the alarm can only be ended by disconnecting S1. When K acts, its normally closed contact Kl is disconnected, cutting off the engine ignition circuit.

The receiver circuit consists of TDA7010 and switching power amplifiers TWH8778 and TWH68. When IC2 receives the alarm signal, the high level of its mutual pin is amplified by IC3 and IC4, and TWH15 emits an alarm sound. However, the stability of the frequency must be taken into consideration, because the 7010 itself does not have a frequency stabilization circuit. It requires more testing during operation. It is best to use printed boards and chip components.

After parking the vehicle according to the above operation method, the alarm will enter the alarm state. During the period of waiting for the alarm, as long as someone opens the front lock or moves the vehicle using any method, the alarm will be triggered and the alarm will continue, and the engine power will be cut off so that the vehicle cannot be started until the owner of the vehicle arrives and inserts the ignition key into the ignition lock. The alarm can be released only when the switch is in the off position.