Touch alarm circuit is widely used for security, which is installed on the door. The advantages of this alarm is because the cost is cheap and difficult to detect by burglars / intruders. The following is an example of a touch of alarm circuit which is designed by Tony Van Roon. Components List: R1 =… Read More »
This is the sound generator which will simulate British police car siren. The circuit is built using 2 pieces of timer IC 555 to generate sound frequency. How the circuit work:
Flame, gas and smoke detector for fire alarm. You can combine this circuit with alarm circuit. The output will be the relay which switch on and switch off the alarm. Schematic diagram:
This is Electronic Siren circuit diagram which use standard discrete components. The sound produced imitates the rise and fall of an American police siren. When first switched on the 10u capacitors is discharged and both transistors are off. When the push button switch is pressed to 10u capacitor will charge via the 22k resistor. This… Read More »