[epion2985]

Trying to find something for a special project. Posted in the portable and full size amp sections but no luck. Maybe someone here can help.

I need a small amp board to amplify a microphone signal. It needs to take a lot of power; will probably be using 12v LiPos to drive it. The signal is used to drive an electromagnet that drives something else that needs magnetic flux so while good signal quality is desired this wont be subjected to HiFi Audiophile scrutiny. Has to be small because its going in to something portable.

If anyone know of one that would work or wouldn't mind making one speak up, and thanks as always

 

[sergery]

Perhaps some more specifics would help get the ball rolling. What is the signal? voltage modulation between zero and x, constant current? What is the nature of the transients, in other words will amplifiers designed to work well in the 20Hz - 20kHz range work well or do you need something faster? What is the voltage amplification required to meet your magnetic flux requirement? Does variable current on that end matter? It may be as simple as making a cmoy with correct gain - that is about as compact as they get.

cheers,

serge

 

[diditmyself]

Maybe you should look at one of those cheap Chinese class D amps at Ebay. Many of them are recommended for 12V supply. Use it with a small cheap battery powered opamp based microphone amp that can be found "everywhere".

 

[epion2985]

Quote:

Originally Posted by sergery /img/forum/go_quote.gif Perhaps some more specifics would help get the ball rolling. What is the signal? voltage modulation between zero and x, constant current? What is the nature of the transients, in other words will amplifiers designed to work well in the 20Hz - 20kHz range work well or do you need something faster? What is the voltage amplification required to meet your magnetic flux requirement? Does variable current on that end matter? It may be as simple as making a cmoy with correct gain - that is about as compact as they get. cheers, serge

Thanks for the help! I am an ME major and don't know much about sound engineering or too much about electrical engineering when it comes to circuits so if I come off a bit odd bear with me

The signal is what the mic is picking up (music). I would wire it directly in to the electromagnet but it wouldn't be strong enough to achieve sufficient magnetic field strength (just a hunch). The problem with specifics is there are none this early in the game. And to do the calculations is either very tedious or downright impossible due to geometries. I am going to figure this out experimentally as it will yield a much faster result and then go from there.

Right now I am basically looking for board that can amplify the voltage of the signal leaving the mic up to 12v as I theorize that might be enough. Maybe later I will optimize it down or up to whatever it needs to be but right now I just need something to test and twink with. Actually doesn't have to be small at this point, I was probably to hasty with that one.

Constant current? Well yes as long as there is sound picked up by the mic there should be a signal leaving it. I suppose there is always ambient noise so there should be a threshold but that's probably on the mics end of the deal (correct me if I am wrong).

20Hz - 20kHz range sounds good.

Lets say, for now, that variable current does matter.

Will look in to cmoy diy amps, thanks for the tip

Quote:

Originally Posted by diditmyself /img/forum/go_quote.gif Maybe you should look at one of those cheap Chinese class D amps at Ebay. Many of them are recommended for 12V supply. Use it with a small cheap battery powered opamp based microphone amp that can be found "everywhere".

thanks, will take a look