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Hi i am currently working on a project which deals with lock in amplification system, all this time i have been working on analogue electronics but now my supervisor wants me to convert the system into digital at the last minute
the main part of my project is the phase sensitive detection stage...
basically my square wave is the refernce signal ... so in ur circuit i see one input branchin into the opamp .... i am a bit confused about that ... cud u help plz .... or in other words ... wud i provide both my signals in this circuit ?
thank you so much for the reply earlier yesterday ... so i suppose u r askin me to use a basic synchronous demodulator circuit for the experiment .... u showed me a diagram earlier .... does that have the capability of multiplying a sine wave and a square wave ? and also the IC that u used (cd...
thank u very much for the earlier response
I have modified the no noise circuit by reducing the input values of the demodulator .. n thus it is not overloaded now anymore ...although i am confused about what u meant about the circuit missin a high pass along the signal path
with the noise...
multisim demodulation
thanks a lot for the co operation so far .... i really appreciate it .... i will attach both the multisim files with and without noise in it ... please chek the output from the demodulator for both the cases .... please let me know the feedbacks ... and once again i...
multiplying based phase sensitive demodulation
so u r sayin dat in no way i am supposed to get a half rectified wave even with the addition of noise and as such i might have some problem while providing the two signals to the demodulator ?
am square wave demodulator circuit
sorry about the reply again .... the output that i am gettin now is like a half rectified wave .... but i am supposed to get a fully rectified wave
as for the demodulator i am using a demodulator chip known as the AD734 .... i will attach the datasheet for...
what is a demodulated output
sorry about being vague ..... the thing is .... as i described earlier .... i wil have to build a circuit which wil extract very weak signal from noise which is atleast 10 times larger than the original signal
only using a low pass filter here wont give me the...
what is meant is demodulation?
Hi guys I previously posted here asking for a help with the noise source and I really really appreciate the help from everyone.
I am working on a project which is based on lock in amplification. Basically the main phase of the design is the phase sensitive...
I jus wanted to say thanks a lot for the help .... the circuit is givin me proper results now .... i am gettin noise but its relatively reallly smalll .... i am only allowed to use the basic 741 op amps .... is there any other way to amplify the noise with a very high gain ? once again thanks I...
I tried using two 741 opamps bak to bak .... each havin a gain of 100 .... so technically dat shud give me 10000 gain, please do correct me if i am wrong since i am not a pro ... was the method dat i used wrong ?
I have already tried that circuit from maxim on a breadboard.... doesnt give me any noise output when i chek on the oscilloscope ... i have also tried simulating the circuit in multisim.... but no luk :(
doesnt the zener diode c27 has a characteristic breakdown point of 2.7v? I thought that is the case so providing a voltage source above it will cause the avalanche effect, i gues i was wrong. Also if I do use a shift register, do i need to program it since its a digital device? Can you please...
I am sorry for not being clearer earlier. I am working on my final year project which is named DESIGN AND BUILD OF A LOCK IN AMPLIFIER. My main aim of the project is to extract and amplify very weak signals buried in very high noise. I have pretty much built up the circuit for the extraction...
Hi I am not quite sure what you wanted me to do .... could you be a bit more specific please ? I have attached a picture of what I am trying and i am quite convinced something is not quite right in the circuit, could you please help me out ?
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