adding noise source to a circuit

[mpradhan1]

Hi i am working on a dissertation project known as the lock in amplification of a signal buried in noise .... i am buildin da basic ciircuit but wht i am confused about is how do i add a noise source in a breadboard using basic electrnic components ... i will really appreciate da help

 

[audioguru]

Amplify the noise produced by a zener diode or a reverse-biased emitter-base diode that is avalanching.

 

[RadioRon]

One example of what Audioguru is referring to:

**broken link removed**

 

[Mikebits]

Noisecom also makes devices. One package soulutions.
**broken link removed**

 

[medsol]

can't we produce noise via an inductor or unshielded component?

 

[mpradhan1]

hi .... do i jus connect da zener diode in reverse biased series mode .... n provide a voltage more than da breakdown voltage .... if dats da case i am tryin it in multisim electronic workbench but i am not seeing any noise in da output .... may be i have da circuit wrong .... any help ?

 

[Mikebits]

hi .... do i jus connect da zener diode in reverse biased series mode .... n provide a voltage more than da breakdown voltage .... if dats da case i am tryin it in multisim electronic workbench but i am not seeing any noise in da output .... may be i have da circuit wrong .... any help ?

Try using full complete sentences. No one will take your seriously if you use text speak like n... da... or dats...

 

[ericgibbs]

hi .... do i jus connect da zener diode in reverse biased series mode .... n provide a voltage more than da breakdown voltage .... if dats da case i am tryin it in multisim electronic workbench but i am not seeing any noise in da output .... may be i have da circuit wrong .... any help ?

hi,
Post a drawing on how you have connected the zener to the circuit.

 

[mpradhan1]

sorry about earlier for using short texts , anyways i am not entirely sure about how to connect the circuit either, i am pretty sure whatever i have done is stupid, I just tried to follow what one of my seniors wanted me to do, i have attached a picture file and i hope you people can help me out, thanks a lot so far

 

[ericgibbs]

sorry about earlier for using short texts , anyways i am not entirely sure about how to connect the circuit either, i am pretty sure whatever i have done is stupid, I just tried to follow what one of my seniors wanted me to do, i have attached a picture file and i hope you people can help me out, thanks a lot so far

hi,
Have a look at the way Maxim do it.

**broken link removed**
**broken link removed**

 

[mpradhan1]

I am confused about how to check the signal for noise in it in multisim, i mean since i am using a dc power supply the only thing that i notice in the oscilloscope is a straight line without any noise interference in it, what am i missing out? your help will be greatly appreciated

 

[ericgibbs]

I am confused about how to check the signal for noise in it in multisim, i mean since i am using a dc power supply the only thing that i notice in the oscilloscope is a straight line without any noise interference in it, what am i missing out? your help will be greatly appreciated

hi,
I dont use multisim, but its possible that it only shows the 'ideal' output from the zener/amp rather than the true signal with noise.

I would suggest the only way to see the 'noise' would be to build the actual noise circuit and use a wide band scope to see the noise.

 

[mpradhan1]

thanks a lot for the help