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Thermal White Noise  Johnson–Nyquist noiseby Mechatron
Tags: alternating current, batteries, battery, frequency, johnson–nyquist, noise, nyquist, signaltonoise, thermal, thermal noise, white, white noise 
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#55
Feb614, 08:36 PM

P: 1,074

A simplified block diagram of an analagous system would allow us to talk about it coherently. As it is, it is all arm waving and misunderstanding. You words can be interpreted in many ways, and we (well, they, actually) are slowly honing in on the narrow set of assumtions you are unconsciously making. The field is very broad, and you are viewing it with a set of hidden assumptions. An architectural diagram would help immensely.



#56
Feb614, 08:40 PM

P: 38




#57
Feb614, 08:48 PM

P: 38




#58
Feb614, 09:23 PM

P: 585

You have a 20KHz clock, and it is measuring 20400Hz with a frequency counter? Have you tried replacing the suspect "hot" battery with a bench power supply? 


#59
Feb614, 09:28 PM

P: 38




#60
Feb614, 10:01 PM

Mentor
P: 40,717




#62
Feb614, 10:05 PM

P: 38

New theory:
The flicker noise is carried on the 20 kHz signal, so the signal is a carrier signal. In addition to try to calculate the cut off frequency of the flicker noise. From a different thinkoutsidethebox perspective; If you can calculate the noise voltage using Johnson's equation for every instance (a unit of time): If the noise voltage is 0 at 0 ms, 1 V at 250 ms, 0 V at 500 ms, 1 V at 750 ms and 0 V at 1000 ms, don't you agree that the frequency is 1 Hz? So since the thermal radiation generate random noise and generate a noise voltage, and the noise voltage vary, then we can say that the thermal radiation actually does have a frequency on the carrier signal. 


#63
Feb614, 10:22 PM

P: 585

Or maybe yes if for this one particular second this random noise voltage just happened to trace out a sine wave. How likely would you expect this to be? 


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