How to design a lock-in amplifier?

[theflyingmachine]

Lock in Amplifier

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!

 

[mago]

Re: Lock in Amplifier

Hi theflyingmachine,

A lock-in amplifier is a device that amplifies a small signal, using modulation techniques. your signal must be pulsed (AC). Simplifying a lot, you could think as if you multiply your detected signal + noise with a reference and then filter the signal. synchronous detection.

You can find information on many books like: Horowitz, Basic electronics for scientitst, experimental methods for physics.

you can try www.lockin.de
or try www.signalrecovery.com, they have a lot of good articles about it
(i don´t know if the above links are still working)

good luck

 

[hung_wai_ming@hotmail.com]

Lock in Amplifier

Hi mago

Do u have real circuitry to share and let us learn that?

 

[theflyingmachine]

Lock in Amplifier

I need a simple circuit which I can make and not an instrument. Please help!

 

[mago]

Re: Lock in Amplifier

Actually, i have to do some kind of lockin amplifier, but it´s not my priority right now... when i finished the prototype, i wil share with you, it´s not so diffcult as it seems, if you know a bit of modulation you can do it yourself. ( at least is what i think, i don´t know if i am too optmistic...:=)