Gate type of thing

[Martin]

Okay, what I'm looking for is a device to automatically power down our infrared hearing system when no input level is present. This would consist of a device that you can feed audio into and it will trigger a relay. Then when the audio stops, the relay switches off.

 

I guess what I'm after is a low end gate in a simple package. It would probably just need a threshold control, but a 'release' control running to minutes, would be useful to prevent chatter.

 

Either an off the shelf product or a simple circuit idea would be most welcome.

[robloxley]

Do you actually want to turn the system off, or just want a simple noise gate? Though I'm not sure why you might want such a complicated system to turn it off physically.

[Martin]

Yes I'm looking for something to physically cut power to the IR controller (which then switches off the IR radiators). It would have been good if it was an option built into the controller.

 

I'd prefer not to leave the radiators on permanently. Though I don't know what sort of life these things have, or if they are designed to be left on permanently.

[simon-carter]

Hi

 

I happened to come accross this recently - could be of use - http://sound.westhost.com/project38.htm.

 

Simon

[Peter Russell]

I guess what I'm after is a low end gate in a simple package. It would probably just need a threshold control, but a 'release' control running to minutes, would be useful to prevent chatter.

You will also need to think about a bypass for this circuit during shows, you wouldn't want the system shutting off just because the show has a quiet bit,

but then a bypass would defeat the object :(

 

I would stick to turning the system on and off as I think anything automated would just turn into complete pain, it's only one more thing for your preshow checklist.

 

Peter R

[robloxley]

Strangely enough, Sennheiser seem to avoid making any life-expectancy claims on their IR radiators, though maybe they'd be forthcoming if you asked. Not sure what the ballpark figure for IR LEDs might be?

 

Anyway, why not just switch them on when the house opens and off at the end of the show? Lots of places have some kind of state system (e.g. Northern Light's night/day/rehearsal/performance working light systems) that control working lights, houselights and other functions that you might tap into with the addition of another contactor.

 

With a sound-detector type device, what'll no doubt end up happening is that they come on when the cleaners get in in the morning, stay on through rehearsals / matinees / stage work, and not go off until sometime after the evening show. At that point, you could just have a switch and make turning it on/off part of the unlocking/locking up regime.

[Martin]

Thanks Simon, that looks like just what I'm looking for.

 

Peter wrote:

You will also need to think about a bypass for this circuit during shows, you wouldn't want the system shutting off just because the show has a quiet bit,

but then a bypass would defeat the object

That's why I suggested a 'release' option that you could set to about 30 minutes, so they don't switch off mid show.

 

 

The reason I want to automate this is because the theatre is used as a lecture theatre during the day, but we don't look after the technical aspect of the lectures and the lecture techs currently don't have access to the IR modulator in our amp room.

 

I have emailed Sennheiser and will report back if anyone is interested.

 

Many thanks for all the replies, :(

[Andrew C]

Just a thought, but could phantom power from the desk (if the set-up is connected) be used for this. I accept that you'd need to connect the 48v to the output side, and that de-coupling would be needed, but it might be a simpler project.

[MarcT]

How about a timeclock???

 

On at 8am, off at midnight?

[TomLyall]

How about a timeclock???

 

On at 8am, off at midnight?

 

therefore saving 8 hours? I'd really start to wonder if turning this system off is worth it, it is proven that most damage is caused to electrical equipment at startup/shutdown....

[robloxley]

I'd have thought the concern is more the life-expectancy of the LEDs; however I'm not sure how much of a concern that should be?

[Dicky]

I know this is an old thread, but I thought I'd post this info here, as it's something I've just done in my venue and it may be of some use to others.

After having had several Sennheiser IR radiators repaired via the costly sennheiser repair service, I found that in all cases it was the PSU inside the units failing and CPC sell the generic PSU board that goes in them, part number PW01237 at a fraction of the cost.

I've also installed some of These in the distribution board where the radiators are powered from which is programmed to turn them all on during the day/evening and off overnight which will hopefully lead to the PSUs lasting longer and will eliminate the error of technical staff failing to turn them on!

FYI the 8 units I have in my venue have been on constantly for 6 years and I've yet to see any LED failures, only PSU failures.

In my previous venue we had a switch in the control room to turn them on and off for each show and similarly I didn't' see any LED failures over a 4 year period from when I installed them to when I left.

 

Dicky

[Andrew C]

Wow! Six year old necromancy...

 

However, I'm not complaining as I was told last night that the system in our theatre was playing up. I know "sound" was leaving the amplifiers, I'll bet that the radiators are duff. Ahhh, well, add it to the list of jobs.