Amplifying Millivolts to Volts

Caiden

Feb 18, 2014
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Hi guys, I trying to amplify 10 millivolts into 1 or more volts I was wondering if anyone knew how to do that. I'm really in a rush so please resond quickly.
 

Harald Kapp

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Welcome Caiden.

There are many ways to amplify a signal. Is it DC or AC?
What frequency range?
What is the impedance of your millivolt source (how many mA or µA does it deliver)?
What output current required?

You can "amplify" AC with a simple transformer (you can't do that with DC).
You can build an amplifier based on transistoirs, or use an integrated operational amplifier.
 

Caiden

Feb 18, 2014
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Thanks for answering me, its dc and I really don't know how many mA and current but I'll have to see. I've tried using an op amp but I just can't seem to get it right.
 

Caiden

Feb 18, 2014
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I'm just trying to amplify 10 millivolts to make it usable. So basically If it's ac it has to be 110 volts but if I do dc it has to be enough to charge a phone. Do you know what I mean?
 

BobK

Jan 5, 2010
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So, let me see if I have this right. You have a power source that puts out 10mV at some unknown current, and you want to boost (not amplify, that is a different thing) this power to 5V to charge a phone.

When you boost a voltage, you diminish the current by the same factor (actually more since 100% efficiency is unachievable). So to get the standard charging current of 1A you would need 500 Amps from your 10mV source, which I suspect is a wee bit higher than is available.

And typically, boost circuits don't work much below 1V. So we are getting into the area of energy harvesting (look it up). This involves accumulating the energy from a low power source over a long time to then use it in a burst for a short time. This allows you to power something that the original source is not able to power directly. For example, if your 10mV source produced 1 A (which is probably still way high), then you could accumulate the energy from it for 1500 hours in order to be able to charge a phone at 1A for 3 hours.

Good luck with your project.

Bob
 

Caiden

Feb 18, 2014
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Sorry guys I just barely figured out that it's not amplifying it power converting i'm really sorry.
 

(*steve*)

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Jan 21, 2010
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Sorry guys I just barely figured out that it's not amplifying it power converting i'm really sorry.

That's fine, it's a common misconception.

Maybe this has saved you some misplaced effort. :)
 
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