fm radio controller anti theft alarm


Posted on Feb 5, 2014

This Circuit of FM radio-controlled anti- theft alarm can be used with any vehicle having 6- to 12-volt DC supply system. The mini VHF, FM transmitter is fitted in the vehicle at night when it is parked in the car porch or car park. The receiver unit with CXA1019, a single IC-based FM radio module, which is freely available in the market at reason


fm radio controller anti theft alarm
Click here to download the full size of the above Circuit.

able rate, is kept inside. Receiver is tuned to the transmitter`s frequency. When the transmitter is on and the signals are being received by FM radio receiver, no hissing noise is available at the output of receiver. Thus transistor T2 (BC548) does not conduct. This results in the relay driver transistor T3 getting its forward base bias via 10k resistor R5 and the relay gets energised. When an intruder tries to drive the car and takes it a few metres away from the car porch, the radio link between the car (transmitter) and alarm (receiver) is broken. As a result FM radio module gene-rates hissing noise. Hissing AC signals are coupled to relay switching circ- uit via audio transformer.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Oscillator operates from one cell
Low-cost-humidity-sensor
Undervoltage lockout for small-power MOSFET gate driver
smart amp delay
Build Your Own Gauss Meter
Battery charging indicator circuit
Simple 10W audio amplifier
Beeper & Buzzer Schematics
Astable multivibrator in an 8 pin PIC
Introduction
FOUR MODE FREQUENCY COUNTER



Top