Light-Operated APPLIANCE SWITCH

Automation is now integral to daily life, with mobile phones serving as essential tools.

- SURESH CHANDRA DWIVEDI

This device employs a mobile phone torch to control domestic appliances, exemplifying an efficient light-operated switch. By responding to light intensity, it activates or deactivates appliances with ease.

The switch detects ambient light through a light-dependent resistor (LDR) or photodiode. A focused beam from a mobile torch, standard torch, or laser torch triggers the system—powering the appliance on with the first focus and off with the second. The LDR in circuit translates changes in light intensity into electrical signals, driving the switching mechanism.

With versatile applications, this device can be handy for individuals with physical disabilities, enabling effortless appliance control. It is equally effective for managing indoor and outdoor lighting in homes. Fig. 1 shows the author’s prototype on a breadboard.

Circuit and working