Help with LDR sensors?

Thread Starter


Joined Nov 12, 2015
Hello. Can anyone please help me with building a multi sensor, multi relay circuit? I've watched thousand videos but they all show how to build circuit with one sensor and one output. My objective is to have 6 LDRs controlling 6 outputs (relays) all running on the same circuit or grid with as less parts as possible meaning transistors and resistors, to make it simple. I've read about parallel and series connections but still don't know how to put it all together. I just want a relay switch to turn on when light is shining on it's sensor. I would really appreciate it if someone could draw a diagram that would help me understand. Thank you


Joined Mar 30, 2015
I found this in about a minute. Scroll down to the only example. This is the opposite of what you want, so swap the two resistors. Just wire up 6 of them.

You didn't mention any hysteresis requirement, so you may have problems if the light is varying.


Joined Nov 13, 2015
In this regard, there are many articles associated with the sensors.
For example, the following address:

Moderators note: removed non-english link
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