TonyNo
Active Member
A cord like this may be easier to split if your device is not grounded...
http://www.radioshack.com/product/index.js...rentPage=search
http://www.radioshack.com/product/index.js...rentPage=search
I tried this but it doesn't seem to be sensitive enough to light for my application. I am trying to monitor the mute LED light on an A/V receiver. The LED is not very bright when on. Any circuit ideas on how to make the photocell more sensitive to light?
The other option (I would like to avoid if possible) I have is to open up the A/V and monitor the LED directly. What would I need and how would I do this?
Thanks,
Chris
Hi,
I'm now using some relays and power supply connected in the back of my receivers and cableboxes to my SECU16 input to know theirs power status. That was very simple to build.
But your led detectors tip just gave me an idea... Could i use a photocell over the outical output red light? I don'T know if it possible to get an empty TOSLINK connector and put a light detector in it. It would make a clean looking probe. Nothing clued in the front of the TV. And I don't use the optical out.
I know some of you are using CR Magnets to know if your TV are on or off. I would prefer not to split the power cord. It's a new HD LCD.
I have a CdS photocell(LDR?) and a LM393(Op-Amp?).
I have built the Basic CdS Photocell Detector circuit on this page: http://home.cogeco.ca/~rpaisley4/PhotoDetectors.html
IC1 = LM393
R1 = (I have tried the full range of resistors with no luck)
I have this circuit working for "normal" light/dark situations but it doesn't work when monitoring the faint LED light on my A/V receiver.
Any ideas on how to make this more sensitive to light?
Thanks,
Chris
ok, I get about 20K Ohms when the LED light is on and a 1(Infinite) when it's off.
Thanks,
Chris