simple touch switch circuit


Posted on Feb 5, 2014

Similar to the CMOS based Touch Switch also on this site, this transistor based touch switch can activate a load simply by the user touching a metal plate. It is designed to directly switch a relay to allow it to be used with large loads. As it uses only a few commonly available transistors and a 12V supply, it is ideal for hostile environments wh


simple touch switch circuit
Click here to download the full size of the above Circuit.

ere mechanical switches would be damaged. Using a latching relay and two of these circuits, a simple two pad "touch on/touch off" arrangement can be made. The touch pad can be most easily made by cutting a small square of PCB material and then soldering on a single wire. Alternatively, something like a penny glued to a plastic backing will do the job. As mentioned, a latching relay can be used so that a momentary touch activates the relay and it remains active. To turn off a latching relay, power must be interrupted. So a 2nd circuit with a normal relay can be used to cut power (use the NC contacts on the 2nd circuit). Placed side by side, two touch pads form an "on" and an "off" pad.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    AVR FM Stereo Transmitter
    AC Millivoltmeter Adapter
    Pierce crystal oscillator
    Simple continuity checker
    MultiKey - One Wire Keypad
    Dummy Alarm Project
    vfd
    IR Headset Circuit with headphone Transmitter and Receiver diagram
    Automatic Ac Line Voltage Selector
    TDA2030 200 watt amp low cost audio power amplifier
    interfacing servo motor with 8051 using keil c
    A TREAD sized regulator
    Push Button ON-OFF Soft Latch Circuits
    High voltage speed optocoupler and application circuit diagram
    Single Span HF Test Oscillator



    Top