10 simple touch switch using transistor

This  circuit is no doubt one of the simplest touch switch circuit
using transistors configured in a Darlington form. When you touch
the touch plate, your hand will provide a several ohms of resistance
that is enough to make a close circuit between the base of the
transistor and power supply. Touching the plates lights the LED
up but it will automatically tuns off when plate is not touched.
Materials:
2 - general purpose transistor (9013, 2N222, others)
1 - 100k resistor 1/4 W
1 - 100 ohm resistor 1/4 W
1 - 6V to 9V battery
1 - LED (preferably red)



Note that  this touch switch circuit may not work properly when
the supply is a rectified dc from an ac source.

10 comments:

  1. Excuse me, what do you mean by touch plate? how can i make this?or should i buy this thing?

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  2. Saidaliah good day!
    touch plate or touch pad. its just a piece of of any conductor formed like the figure above.The main purpose of this is when you touch, your finger will acts as a conductor that will connects the two wires.
    When making touch plate,just copy the diagram above using cooper in a pcb but make sure that this wires are not separated.You dont have to buy, just any piece of conductor that is formed like above diagram will do.

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  3. hello DH-GM, how can i make this circuit a little complicated? Like for example, if i touch the switch, the led will light and turn off only when i touch the switch again. thAnks!!=)

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  4. SIR,
    WHAT IS TOUCH SWITCH AND GIVE ME LITTLE BRIEF EXPLANATION REGARDING IT.

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  5. To Franzemyll,
    This simple circuit is made just to show how a transistor work and what are the possible use.
    Based on your question, i assume you are referring to a flip flop circuit. I have circuit that is similar to what you ask. i recommend to view it and even modify it. Link below
    Clap Switch

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  6. To Sushma.
    When you touch the touch plate, your body provides continuity to the circuit thus turning on the transistor.

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  7. sir,
    thank you sir,and also i want to know about the working of the mobile cell phone charger.

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  8. can i use other transistor .....? If yes mention the value of transistor

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  9. What if the touch plate is not connected to the power supply only connected below to the resistor, and so on. Will that work if the touch plate is touched?

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