be detected the pendulum swings and activate the circuit. The circuit is using an FM transmitter at the output to broadcast a tone on a FM radio.
Working of the circuit is simple when the pendulum swings it touches the loop and triggers the IC1 for a preset time period, which depends on the 1M variable resistor and the 100uF capacitor. When IC1 is triggered it activates IC2 and the transmitter circuit. The IC2 generates a continuous tone, which is transmitted on a FM receiver though the FM transmitter. The transmitter part of the circuit required some tuning for the first time. The 1M pot between the pin 7 and 8 of the IC is used to adjust the tone. The 10K variable resistor is used to adjust the volume of the tone. The variable capacitor TR is used to adjust FM broadcast frequency of the circuit. The operating voltage of the circuit is 4.5V to 6V DC. The antenna can be a 12 inch wire. For further distance use 80 centimeter antenna.
Here is another great project of a wireless movement sensor or monitor circuit. The circuit can monitor your large objects and inform you wirelessly at a distance of upto 50 meters to a remote location on an FM receiver. For example it can be placed in your car and when any movement will