Automatic MUTE LM3886

[epilot]

Hi guys,

Is it possible to automatically MUTE a LM3886 amplifier while there is no input frequency?
I mean for instance if you have a mike connected to the LM3886, then for whiles that you do not talk to the mike the LM3886 turns off, and as soon as you start to talk to the mike the LM3886 starts to normall working.
Is it possible to do so?

Thanks.

[ratza]

Yes it is, but I don't see the purpose.

[epilot]

Originally Posted by ratza

Yes it is, but I don't see the purpose.

Thanks sir for your reply,

I would like to know how to do that?
Honestly I think that to do so we have to realize the presence of an AC input signal (Ie the input signal of the mike produced by the speech) then give a DC voltage to the mute pin proportional to presence of the AC input signal. right? or there is another way to do so?

I just like to turn the amplifier off while there is no input signal.

[godfrey]

All the mute does is effectively disconnect the input from the amp, so muting when there's absolutely no input won't achieve anything.

I'm guessing what you want is to stop the amp amplifying background noise when the guy at the mike stops talking. If that's the case, then what you described is the way to do it.

You'll need to set a threshold (preferably user-adjustable) below which the amp mutes. There should also be a small delay on the mute so it doesn't keep cutting in and out between words when the guy is talking, but the "un-mute" when the signal goes above the threshold should be instantaneous so you don't lose the first word when he starts talking again.

I think this kind of thing is quite common with PA systems, but I don't know what it's called.

[AndrewT]

what does "squelch" do in a transmitter?

[godfrey]

Thanks for the clue, Andrew. Following a couple of links in Wikipedia brings up what's needed: Noise gate - Wikipedia, the free encyclopedia.

So "noise gate" is the term to search for more info.

[AndrewT]

Team Working.

I should arrange a usb link between my terrible memory and your research skills.

It took two attempts to just spell it.

[godfrey]