# How to Amplify 0.1V across an LED terminals to 3V ?

Discussion in 'The Projects Forum' started by 5416339, Aug 25, 2010.

1. ### 5416339 Thread Starter New Member

Aug 25, 2010
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0
∞I made a circuit in which the LED terminals have a potential difference of 0.1V,So how can i amply this potential difference to 6V using an external power supply.

I found this circuit : http://www.aldinc.com/pdf/amp_27007.0.pdf

I was wondering if this would amply 0.1V or is it something else ? is this is not the answer then please help me.I have to do this somehow

Thanking You,
5416339

2. ### tom66 Senior Member

May 9, 2009
2,613
214
You'll find it difficult to boost 0.1V. It is a very low voltage.

However, if you already have a 6V or 3V power supply then you can use a comparator to check if the voltage is about 0.1V; this could then control an LED. Or, you could use an amplifier circuit, with a gain of 30 or 60.

3. ### 5416339 Thread Starter New Member

Aug 25, 2010
8
0
So will this work for sure ? Is there any circuit diagram for this type of amplification ?

May 11, 2010
241
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Are you trying to use this 0.1V to sense something, like light perhaps?
Or are you trying to harvest the energy in it?

If you are trying to sense the voltage, then you can amplify the voltage of the signal using a simple non-inverting amplifier. Follow this link.

You will power the op-amp with an external power source, like you mentioned that you have. It will multiply the voltage of the input signal Vin and output the result at Vout. You can power it from ground to the (+) of the source, say +6V.

You must choose an op amp with rail-to-rail input, and may as well use rail-to-rail output, too. They are common nowadays.

If the 0.1V signal is very weak, meaning high impedance or low current, then you must also be careful to select an op amp with a low input bias current. Most likely something of a few pA is okay for you.

Another thing to look for is low input offset error on the op amp. This is important because it will reduce the error in the result of the multiplication.

I would not use that ALD circuit. That is meant for ultra-low power consumption, but it is not the best circuit for accuracy of the results.

5416339 likes this.
5. ### 5416339 Thread Starter New Member

Aug 25, 2010
8
0
What is ALD circuit ?

May 11, 2010
241
38
The link that you posted is to a circuit using ALD chips, on the ALD website.