How to make door Alarm Circuit using scr
Door Alarm using SCR SCR ( silicon controlled Rectifier) also called Thyristor is a semiconductor controlled rectifier is a four layer solid state current controlling device. Components : 1. 1 × Low Power scr 2. 1 × 9v Battery 3. 1 × buzzer 4. 2 × Switches 5. 1 × 1k ohm resistor ( may be vary) Circuit Diagram : Door Alarm system using SCR Working : 1. Make circuit as per Circuit Diagram. 2. Place switch in on door in that way when door is open, switch is closed. 3. When Switch is closed a triggering pulse apply to gate and scr is turn on. Attention : To turn off buzzer place one more switch between positive terminal and scr anode. OR remove Battery