# TOUCH SWITCH | How to Make a Touch Switch Using a Transistor and Breadboard.

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## Introduction: TOUCH SWITCH | How to Make a Touch Switch Using a Transistor and Breadboard.

### Teacher Notes

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## Step 1: THINGS REQUIRED.

1. A BC547 TRANSISTOR

2. 1KOHM RESISTOR

4. LED

5. WIRES AND TOOLS LIKE WIRE CUTTER.

## Step 2: THEORY OF THE PROJECT.

The normal (untouched) circuit is open and no current passes through it. When we will touch the two wires coming out from the transistor (one from the collector and another from base), the circuit gets complete and thus current flows making the LED to glow.

This happens due to the transistor. It has three pins. Collector, Base, and Emitter (as shown in the figure).When the two pins i.e. pin 1 and pin 2 are not touched, the circuit is closed but when we touch both the pins at the same time, the current passes through our body, making a path i.e. connecting pins 1,2&3 in series hence current flows through the transistor which gets out from collector to the negative of the LED and makes the circuit complete, glowing the LED.

## Step 3: PROCEDURE

STEP-1: PLACE THE TRANSISTOR ON THE BREADBOARD AND CONNECT TWO WIRES FROM THE COLLECTOR AND BASE PINS RESPECTIVELY.

STEP-2: CONNECT THE EMITTER PIN OF THE TRANSISTOR WITH THE NEGATIVE RAIL OF THE BREADBOARD.

STEP-3: CONNECT A 1K-OHM RESISTOR WITH SERIES TO THE COLLECTOR PIN.

STEP-4: CONNECT THE NEGATIVE TERMINAL OF THE LED WITH THE RESISTOR AND THE POSITIVE TERMINAL WITH THE POSITIVE RAIL OF THE BREADBOARD.

STEP-5: CONNECT THE POSITIVE AND NEGATIVE TERMINAL OF THE BATTERY (POWER SOURCE) TO THE POSITIVE AND NEGATIVE RAIL OF THE BREADBOARD AS SHOWN IN THE VIDEO.

FOR MORE DETAILED INFORMATION, PLEASE WATCH THE VIDEO AND THE DIAGRAM ATTACHED.

## Step 4: RESULT.

WHEN WE WILL TOUCH BOTH THE NAKED WIRES FROM COLLECTOR AND BASE PINS OF THE TRANSISTOR, THE LED BULB GLOWS.

THANK YOU!

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## 2 Discussions

I'll be posting another video about it's application. Keep Waiting For that.:)