Touch alarm hand made on GPB (General Purpose Board)

Introduction

• The circuit above is the simplest Touch Switch. It is called a "super-Alpha pair" and is actually identical to a single transistor with a very high gain.
  Putting a finger on the touch pads turns the top transistor ON and this transistor turns on the bottom transistor. When the finger is removed, the circuit consumes less than a micro amp.

   

           The 555 can be used to create a Touch Switch. The only problem with this is the 555 consumes about 8mA, at all times when the supply is connected. The circuit above turns on the BUZZER when the finger is applied and pin t becomes "open circuit." This allows the 10u to charge via the 100k resistor and when pin 6 detects a HIGH, the BUZZER turns off. The finger should be removed before this occurs. See below for an ON-OFF touch switch using a 555.

What is Included?

• Project Definition ( by Email )

  Project Circuit Diagram ( by Email )

  Project Report ( by Email )

  Project ( by Courier)