You only learn by doing it

World of Electrons

Project Staircase Lighting

using SPDT Switches

Experiment 18

Circuit Diagram

Materials Required

i. Breadboard

ii. LED - 1

iii. 9V Battery - 1

iv. Resistors: 1k Ω – 1 Color Code: 1k - Brown Black Red Gold

v. Connecting Wire Pieces

vi. SPDT Switch - 2

Step No.1

Take a breadboard

Step No.2

Connect a 9V battery on the breadboard

Connect two SPDT switches together in the manner shown below. Connect

wires to their middle terminals with their other ends open.

Step No.3

Connect middle wire of one switch with Vcc. Connect the middle wire of the

other switch on any vertical column on the breadboard.

Step No.4

Connect positive terminal of an LED with middle wire of the switch connected

on the vertical column (as in step no. 4)

Step No.5

Connect one of the legs of a 1k Ω resistor with negative terminal

of the LED

Step No.6

Connect the other leg of the resistor with ground

Step No.7

Now you can turn the LED on & off with the help of both the

switches

Step No.8

Observation

You can control the switching action of LED from either of the

switches. This project is very useful in daily life and you may

find this circuit installed in staircases of apartments.

Inference

We can combine two SPDT switches in such a way that the

switching action of an independent circuit can be controlled

using both the switches.

Troubleshooting

Tips

• Ensure that your battery voltage is more than 6 Volts.

• Ensure that the wires of your battery connector are

properly inserted into the breadboard. Red wire should be

inserted into the first row and black wire into the second

row of the breadboard.

• Ensure that the LED is in working state using your

multimeter.

• Ensure that stripped ends of the connecting wires are in

contact with the terminals of the SPDT switch.

Troubleshooting

Tips

• Ensure that the positive terminal (longer leg) of the LED is

connected with one of the common terminals.

• Ensure that there are no loose connections.

• Restrict your circuit to the first half of the breadboard. To

provide Vcc and ground through connecting wires, use

only first 25 holes of the first and second row of the

breadboard.

You only learn by doing it

World of Electrons