Most efficient power amp chip?

[therecordingart]

This isn't guitar related, but I want to build a battery powered white noise/pink noise machine for camping. I don't need hi-fi quality low thd...I need battery efficiency. I'm thinking a LM386, but are there any other ideas? Something quick, cheap, and simple is what I'm after.

[geertjacobs]

Thinking outside of the box:
class d is efficient...

example:
"88% amplifier efficiency prolongs battery life"
http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-380

edit: found a kit
http://www.parts-express.com/pe/showdetl.cfm?partnumber=320-322

Disclaimer: I've never built or used a class d amp, however many seem to get nice reviews. YMMV :-)

[R.G.]

OK, outside the box.

Noise generators tend to use digital shift registers, then filter. Why not generate the random digital switching, then use that to switch MOSFETs from 12V directly to make a high voltage/power version of the digital, and filter it to shushhhing after the power amplification in the MOSFETS. No power amp needed, particularly.

[therecordingart]

OK, outside the box.

Noise generators tend to use digital shift registers, then filter. Why not generate the random digital switching, then use that to switch MOSFETs from 12V directly to make a high voltage/power version of the digital, and filter it to shushhhing after the power amplification in the MOSFETS. No power amp needed, particularly.

Went right over my head.

[Mark Hammer]

Um, just exactly who needs to hear this white/pink noise while you're out camping?  You?  Bears?  Park wardens?  Mosquitoes?

I ask because what you wish to do with that sound determines what sort of efficiency (and power) is needed.  If this is a matter of making it easier for you to sleep over the loons, owls, highway noises, or snoring of whomever you are camping with, then part of your solution involves distribution of sound.

Personally, I've always found that a decent-sized radio, tuned between stations, can make a very effective masking-noise source. And, you also get a radio out of it!

[bluebunny]

If my kids were reading this, they'd say, "Isn't there an app for that?" and "What's a radio?"   

[R.G.]

There *is* an app for that. My dearly espoused one has a sleepy-noise-maker app on her ipad. It has a large number of choices of waterfalls, burbling water, escaping steam, many others.

[Morocotopo]

There *is* an app for that. My dearly espoused one has a sleepy-noise-maker app on her ipad. It has a large number of choices of waterfalls, burbling water, escaping steam, many others.

Waterfall, hmm, ok, soothing, calm...

Burbling water, yes, organic, natural...

Escaping steam??


I picture her getting sleepy, slowly closing her eyes, and suddenly a train whistle "Piiiiiiii!!!!!!!" and her jumping a few feet off the bed!

[Gus]

Two links 
http://www.ti.com/lit/ds/snas145e/snas145e.pdf

http://www.ti.com/wcmcomponents/docs/getcomponentaction.tsp?compVariationId=9106&1875&tabId=7008&familyId=376&docCategoryId=2&litCount=all

[B Tremblay]

If this is a matter of making it easier for you to sleep over the loons, owls, highway noises, or snoring of whomever you are camping with, then part of your solution involves distribution of sound.

Packing an extra cooler full of beer can help alleviate all these issues and more!

[gritz]

There *is* an app for that. My dearly espoused one has a sleepy-noise-maker app on her ipad. It has a large number of choices of waterfalls, burbling water, escaping steam, many others.

Waterfalls, burbling water... I would have to keep getting out of bed to pee - a bit like the beer remedy but without all the good side effects. 

[bluebunny]

There *is* an app for that.

Ha ha!  I should have guessed...