Light operated switch

To make light operated switch, you need to know these circuits:

a. Toggle switch

b. Dark sensor using two transistors

c. How to use a relay

– You need to keep LDR in dark case so that the relay remains active all the time(Pole connects to NO).

– When you put light on LDR, the relay switches off and Pole connects to NC; this operation toggles 555 timer and switches on the LED D1.

-When you put light again on LDR,  LED D1 switches off.

Fig. Light operated switch (Click on the schematic to enlarge it)

You can use this circuit to make remote operated switch.

Fig. Remote operated switch (Click on the schematic to enlarge it)

I am Sagar Sapkota living in Espoo, Finland. I have completed Master's degree in Electronics and Communications with major in Electronics Productization from the University of Turku, Finland. I love to share my electronics works with the world. You can buy my kits at - Sagar Sapkota


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