Lock in Amplifier

[theflyingmachine]

I need to make an amplifier which could amplify very small signals (uV) embedded in noise. The frequency of the signal to be amplified is known. The problem is that the signal has too much noise around it. I was told that a lock-in amplifier can solve the problem but i don't know how to make it. Please help!

 

[Nigel Goodwin]

You need to be far more specific about your signal, you don't give enough information.

 

[Hero999]

Phase locked loop?

 

[mneary]

The frequency of the signal to be amplified is known.

Care to share it with us?

 

[Leftyretro]

I believe lock-in amplifiers are very complex and expensive, mostly used in a lab environment. Not sure I understand the concept completely but it involves moving the signal to another part of the spectrum where there is less noise. Here is what I found quickly;

https://en.wikipedia.org/wiki/Lock-in_amplifier

Possibly if you could give us more details about the signal you are trying to process we might have other less complex suggestions. Noise can sometimes be dealt with by using narrow band filtering but it matters if the signal is carrying modulation information or not.

Good luck

Lefty

 

[theflyingmachine]

I am basically making a conductometric sensor. The output is a differential voltage whose frequency is the same as that of my input (say 1KHz). Now this signal is in a lot of noise. I need to find the average value of the signal. I read in a journal publication that lock-in amplifiers can help in such situations but I could not design one. Wherever I look on the internet, I get the names of instruments like SR 830 etc. which I cannot buy. Please help if you can, I think I have been thorough with the problem statement this time.

 

[Roff]

What is the amplitude and signal-to-noise range of your output signal? You may not need a lock-in amplifier.