Light Actuated Relay Circuit using Photo Transistor

The Sun – Up Relay Switch can be used to provide a audible switch for when the sun comes up. It can also be used to detect a light beam, headlights etc.

The Light Actuated Relay Circuit be office circuit with the light. The prominent point of this circuit be meet the light has fast more using LDR control circuit the very.

Light Actuated Relay Circuits by Photo Transistor

When the light leaves work suddenly. When meet the light makes Photo Transistor work bias current change it has made the transistor works to cause Relay work with. For VR1 perform fine decorate the rapidity of the circuit. This circuit is the circuit is simple.

The equipment that use to replace can. such as Q1 = 2N2222 use other number can replace almost be finished request a kind NPN alike enough such as BC549 or BC337 or C1815 or C945 etc. For oval should use 6V-9V sizes that are valuable the resistance within relay coil about 500ohm. Other detail has a little , then build easily sir.

Keep reading: ‘Mini Phototransistor light switch controller circuit’ »

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First of all thanks for your great works. I’m so appreciated of all your attempts in this marvelous website.
Second of all! I’ve made this circuit. It triggers the relay when light exposes to the LDR. But when it get’s dark, the relay still triggered. What differences should i do to deactivate relay when my LDR scenes darkness again?

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