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Single Bi-Colour LED 3 state meter (off / signal present / overload), adjustable

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jezburns

New member
Joined
Jun 17, 2012
Messages
4
Hi everyone,

I designed and built a single bi-colour stereo LED line-level meter displaying signal present and overload for the inputs of a GSSL bus compressor, as an idiot-check against pushing the inputs too hard. 

It's analogue, comparator based, monitors both phases of the AC cycle and either mono or left and right channels separately (no summing, so an overload at the same level on left channel, right channel or both together will be registered the same).  The threshold for the overload indicator is adjustable with a multi-turn trimmer resistor, and it has two sensitivity modes, for standard line level and hotter inputs of up to around 25dbu.  It can be powered from a single 12v DC supply.

Here's a video of it in action:

https://www.youtube.com/watch?v=R_LewmtpSF8

I had several spare PCBs and components, so if anyone is interested in having one for a project, please PM me and I can sell prebuilt for £40, PCBs for £5 each or you can have the gerber files / schematics for free.  This isn't a commercial venture, just hoping to make back my costs in designing it as an amateur, so I hope this is the appropriate place to post this listing.

Thanks  :)

Jez Burns.
 

jezburns

New member
Joined
Jun 17, 2012
Messages
4
Just politely bumping this thread, as I've had some requests for schematics via comments on the youtube page, and I'd rather people contacted me here..
 

MidnightArrakis

Well-known member
Joined
Sep 25, 2015
Messages
106
Hi everyone,

I designed and built a single bi-colour stereo LED line-level meter displaying signal present and overload for the inputs of a GSSL bus compressor, as an idiot-check against pushing the inputs too hard.

It's analogue, comparator based, monitors both phases of the AC cycle and either mono or left and right channels separately (no summing, so an overload at the same level on left channel, right channel or both together will be registered the same). The threshold for the overload indicator is adjustable with a multi-turn trimmer resistor, and it has two sensitivity modes, for standard line level and hotter inputs of up to around 25dbu. It can be powered from a single 12v DC supply.

Here's a video of it in action:


I had several spare PCBs and components, so if anyone is interested in having one for a project, please PM me and I can sell prebuilt for £40, PCBs for £5 each or you can have the gerber files / schematics for free. This isn't a commercial venture, just hoping to make back my costs in designing it as an amateur, so I hope this is the appropriate place to post this listing.

Thanks :)

Jez Burns.
I would be interested in the schematic of your "Signal Indicator LED Circuit". You can send it to me at: [email protected]

1) Do you know how much current the total circuit draws?

2) Could this be powered by the +48V Phantom Power (with appropriate circuit changes) being fed to a mic?

THANKS!!!

/
 
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