# Stand alone clearcom call light?



## gafftapegreenia (Apr 6, 2009)

So, over this past show I discovered the need a for a visible clear com call light in the house to get ahold of our house manager more easily. Now, I know PI makes strobe pack versions, but honestly, how hard can it be to wire up a simple home-brew clearcom call light? I think I could figure it out if I knew the operating voltage and which wires go where. Really doesn't seem that hard to me. Has anyone attempted this?


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## gafftapegreenia (Apr 6, 2009)

Just did some searching and found a few old threads on this. Kinda what I figured. 

Has anyone actually DONE it, or have a diagram?


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## gafftapegreenia (Apr 6, 2009)

Of course my problem has already been solved, for $25:
Illumineering - Com-bit


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## waynehoskins (Apr 6, 2009)

The call signal is provided by DC bias on the audio line -- something like at least 8 volts. The call detection circuit in the old analog CC packs was dog simple, perhaps as simple as using that to switch on a transistor that lights up the light. Maybe low-pass it, I forget.

$25 isn't bad for an actual product, but it should also be doable for a couple bucks' worth of junkbox parts, if that.


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## gafftapegreenia (Apr 6, 2009)

The junkbox of parts I got.  Hence my desire not to spend $25. Give me a diagram and I"ll breadboard it.


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## aminorking (Apr 6, 2009)

I saw this the other day which might help. It is for a Tecpro, which is mainly used in the UK, but I understand that it is compatible with Clear-Com, could someone confirm that?
But anywho, call light circuit here. Hope that helps.

Edit: Did a bit more searching, Tecpro is 
1:Ground 
2:+24v
3: Signal

Clear-com
1:Ground
2:+30v
3: Signal


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## willbb123 (Apr 6, 2009)

I made a thread asking about this a while ago. Everything I need is in that thread but I haven't gotten around to making it yet. I am on my phone so I can't paste the link in, but either do I search or look at the topics I've started and you easily find it.


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## waynehoskins (Apr 6, 2009)

aminorking said:


> I saw this the other day which might help. It is for a Tecpro, which is mainly used in the UK, but I understand that it is compatible with Clear-Com, could someone confirm that?
> But anywho, call light circuit here. Hope that helps.
> 
> Edit: Did a bit more searching, Tecpro is
> ...



Yeah, Tech Projects is 100 percent CC compatible. They began selling CC-compatible kits long ago.

That circuit will work, but for just lighting a small light it's overkill -- though plenty good for a big light.

For something smaller like a No. 47 lamp, look at Richard Crowley's Comclone schematic (ComClone2 - Schematic Diagram). Of interest is the signal circuit, which has a couple of bus isolation resistors, a low-pass filter, and then a NPN darlington driving the load. That's all you need -- and in fact, if it's a lighter load, you don't even really need a darlington pair.


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