Unable to account for frequency related to Magnet being pulsed by Inductor

[duff]

Amplifies?

Weren't there many folks here that determined a magnet had no real effect upon a coil?

Regardless, Nice work @duff.

@BEP,

The end effect is amplification though I don't really understand the mechanics. When the magnet is placed on the top of the spool it sings at one of the tones heard in the spool center cylinder and is louder. I don't know how the other tone becomes louder because it does not seem to be coming from the singing magnet.


@wattsup

Yes - your video demonstrates nicely the interaction of two signal in a wire with the magnetic field.

EM also demonstrated in a video the current interactions with the earth's magnetic field.

I believe same principle is at work in my inductor.


@all

Thanks for your input and comments


-Duff

[BEP]

Uh-huh.

A little note for those unfamiliar with the many types of hearing loss....

One, the one I am very familiar with, is weaker hearing at specific ranges. The range lost determines what the effect is but mine make me loose directional sense for sounds in the 800 to 2k range. (An ideal excuse when a female is screaming at me).
When I have a smoke alarm crying about a weak battery I just replace all the batteries because it would take me weeks to locate the one complainer.
I'm not surprised locating this sound was a problem. I would still like to know why it sounds around 960 when the coil is pulsed around 100k.

Do any one of you geniuses know how that could happen?

@duff

I've been trying to relate my noise maker to what you have found but doubt there is much relationship. Microphonics is not going to be an issue here because all winding turns have a 2 x conductor diameter spacing to the next turn and only one layer. Inductance isn't an issue since the resonance is determined by the core, not the windings.

BEP

[duff]

I would still like to know why it sounds around 960 when the coil is pulsed around 100k.

I'm also interested in the 960 signal.

Later this week I will take the inductor out of town away from the 60Hz as planned and see if it goes away.

My issue is I'm going to have to take my scope and an inverter. In the event there in no sound I'll need to verify it is still oscillating at the set frequency or perhaps verify the frequency the tone is heard.

Anyway I'm wondering if there is an issue with running a scope off a cheap inverter...


-Duff

[BEP]

I'm also interested in the 960 signal.

Later this week I will take the inductor out of town away from the 60Hz as planned and see if it goes away.

My issue is I'm going to have to take my scope and an inverter. In the event there in no sound I'll need to verify it is still oscillating at the set frequency or perhaps verify the frequency the tone is heard.

Anyway I'm wondering if there is an issue with running a scope off a cheap inverter...


-Duff

If you have a small isolation transformer you should put it between the scope and inverter. It'll soften the power wave shape a bit.
Either way the noise from the inverter can be just as bad as any mains noise in the house. If your inverter puts out square wave and has an effect it should be noticeable.

Do what you think is best but it would be easier to just kill all unused house circuits. Local E/M noise fields should have very limited affecting range, for the magnetic side, unless a load or circuit needs repair already.

[duff]

If you have a small isolation transformer you should put it between the scope and inverter. It'll soften the power wave shape a bit.
Either way the noise from the inverter can be just as bad as any mains noise in the house. If your inverter puts out square wave and has an effect it should be noticeable.

Do what you think is best but it would be easier to just kill all unused house circuits. Local E/M noise fields should have very limited affecting range, for the magnetic side, unless a load or circuit needs repair already.

Ok - I took your suggestion and turned off all the power to the house.

The beat vanished!

I double checked and did not turn off the circuit or disturb anything between test

So it seems that it is the 16th harmonic of the 60Hz grid.

As it turns out TinselKoala NAILED IT on the 5th post of this thread.


-Duff