Speaker as noise detctor.

[H-Man]

I'm trying to find a way to detect electrical noise that dosn't require me to look at the meter.
Would a speaker and a capacitor be able to detect electrical noise, or is it too high of frequency for me to hear?
I'd imagine that I need a few more components to do it right.

[budm]

Re: Speaker as noise detctor.

What kind of the electrical noise? The one that radiates through the air? or in the circuits.

[H-Man]

Re: Speaker as noise detctor.

What kind of the electrical noise? The one that radiates through the air? or in the circuits.

Circuits. ex when you have a bad capacitor in a circuit. I got the idea because I fixed a TV that had bad coil whine and a bad cap.
Coil whine went away when I replaced the bad cap.

[Kiriakos GR]

Re: Speaker as noise detctor.

Circuits. ex when you have a bad capacitor in a circuit. I got the idea because I fixed a TV that had bad coil whine and a bad cap.
Coil whine went away when I replaced the bad cap.

This is a common side effect equal to strong hum which the preamplifier produces due unregulated DC.

Your idea or concept is smart, but practically it does not stand.

[H-Man]

Re: Speaker as noise detctor.

This is a common side effect equal to strong hum which the preamplifier produces due unregulated DC.

Your idea or concept is smart, but practically it does not stand.

The noise and bad cap were in the power supply, not an amplifier.

[tom66]

Re: Speaker as noise detctor.

If you can't hear it due to it being too high frequency, no matter how much you amplify it, it will not matter.

You need an oscilloscope to analyse higher frequencies. Highly recommended bit of kit.

[H-Man]

Re: Speaker as noise detctor.

This is a common side effect equal to strong hum which the preamplifier produces due unregulated DC.

Your idea or concept is smart, but practically it does not stand.

If you can't hear it due to it being too high frequency, no matter how much you amplify it, it will not matter.

You need an oscilloscope to analyse higher frequencies. Highly recommended bit of kit.

I can hear the noise from the coil.
I guess I can just use an AM radio.

[Mad_Professor]

Re: Speaker as noise detctor.

I can hear the noise from the coil.
I guess I can just use an AM radio.

The average human hearing is 20 to 20000 Hz, I seriously doubt you can hear above or below that range.

You could technically do it with a speaker but you still would not be able to hear it due to the limitations of human hearing.

As for the coil, it depends, if it's a loose windings, of course you would be able to hear that.

AM radio is great for finding counterfeit power warts/bricks, problematic devices with poor shielding and arcing or interference coming from the house wiring and it's devices.

[momaka]

Re: Speaker as noise detctor.

I can hear the noise from the coil.

That's probably because the bad cap was causing the power supply output to oscillate. Pretty much all SMPS controllers run at a frequency higher than what humans can hear (usually 50 KHz and above) so you cannot hear them. However, in some cases a bad cap or a low load on the power supply can cause the output to oscillate with a frequency in the audible range for humans, explaining why you heard noise from the coils.

[budm]

Re: Speaker as noise detctor.

The sub harmonic frequency is what you may be hearing.

[turbozutek]

Re: Speaker as noise detctor.

You might be able to train a dog to detect the high frequencies... Lotta' work and expense though when a scope could do it.

Chris...

[Kiriakos GR]

Re: Speaker as noise detctor.

Due the fact that my hearing as human is limited up to 11-12KHz, my vote goes to the suggestion of tom66.