Title:
Touch plate based door bell
Circuit:
Components:
- IC 555
- Resistors: 1 M, 100k, 330 ohms
- Transistor: BC547 PN2222A
- Capacitor: 10n
- 1 Copper plate : as touch plate.
- A 6v battery
- An LED.
Description:
This is the simple circuit for touch plate based security system.In this project what basically done is, circuit detects stray voltages produced by mains voltage and electrostatic built up in the room.If sufficient static voltage is detected by the plate then chip will charge up. Transistor BC 547 or PN2222A is used basically to increase the sensitivity.
Applications:
- In places like museum where precious metal objects are kept.
- In homes, banks, hotels etc
