Fridge door Alarm. Beeps if you left open the door over 20 seconds. 3V battery operation, simple circuitry schematic diagram | Domestic circuits

Fridge door Alarm. Beeps if you left open the door over 20 seconds. 3V battery operation, simple circuitry

For view click Fridge door Alarm. Beeps if you left open the door over 20 seconds. 3V battery operation, simple circuitry schematic diagram