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Changing the sensor Answered

Hello guys,

I want to make this circuit I just don't want any light to be visible. So, I was wondering if I could just change this LDR sensor to a IR sensor and still get the desired results. 



Sure you can do that.
Just take an LDR with its sensitivity in the Infrared range. According to Wikipedia @ http://en.wikipedia.org/wiki/Photoresistor:

"indium antimonide (InSb) LDRs (light dependent resistor) are used for the mid infrared spectral region"

Oh Ok that sounds better. Yeah I had know idea what type of IR sensor mPilch was talking about. But then again, I don't know that much about electronics. I'm getting along though in my Electronics For Dummies book!

So, an LDR that works in the IR range.

Thanks Origami


Origami? :)
Not my name, but i appreciate the thanks! :D

Oh well I like to name people :P

So you want to use an IR beam of light to activate and deactivate the LED?

An IR receiver works a lot differently then an LDR. An LDR is just a resistor that varies it's resistance based on the amount of light hitting it. An IR sensor has 3 pins, ground, voltage, and output. When IR light hits the sensor it will change the voltage and current on the output lead. A simple 555 timer circuit won't cut it when dealing with IR. Look into using a micro controller to help detect an IR signal.

Oh ok. But what about the IR receiver on the top of my little walkbot? It's only got two pins coming out of it.