Understanding coil whine

[HeXploiT]

Has anyone researched coil whine to understand exactly what causes it?
I had previously concluded that coil whine was directly related to voltage.
I Have an Abit IN9-32x Max which I ran two cpu's on.

One was an e6300 and the other an 8400. I have discovered that the motherboard makes no noise if I leave the cpu voltage on "auto-detect" but the second I attempt to manually adjust the voltage the coil(s) begin that annoying buzzing/electrical sound.
What makes this strange is that the e6300 auto-detect voltage is higher than that of the e8400 yet if I attempt to manually set the 8400 to the same voltage as the 6300 the noise kicks in.
I've heard people suggest that perhaps it's only certain frequencies that cause this but I've tried multiple frequencies beyond these chips ratings and they ALL cause the whine.
I'm at a loss and all the discussion I've seen on this topic all end with no answers.

Has anyone else had experience with this issue?

 

[nineball9]

Coil whine is mechanical resonance of the coil with the frequency of the signal passing through it. Physically, a coil is just loops of wire, sometimes with a core other than air. If the frequency of the signal is in resonance with the physical wires of the coil, the coil may vibrate. Oft times, the vibration is beyond human hearing (yokes in TV's can do this), other times it's in the range of human hearing.

There are many electrical parts/circuits which can cause whining noises, so don't just assume you are hearing coils. "Annoying buzzing/electrical sound" are unlikely to eminate from a coil - you have something else making noise. Whining is caused by a part (or parts) physically vibrating.

Unto itself, voltage is not going to cause a whining sound. Voltage is electrical potential (actually, EMF); current through a device is dependent on the voltage across it. With a CPU, changing the voltage probably changes the operating frequency of various components within the processor (I really don't know what is changed), however something is probably in resonance with the signal. If you can narrow down the source of the noise, you may be able to reduce or eliminate it. Try using the paper tube from a roll of paper towels to "listen" to various parts of your system to locate the source.

Good luck!

 

[HeXploiT]

Originally posted by: nineball9
Coil whine is mechanical resonance of the coil with the frequency of the signal passing through it. Physically, a coil is just loops of wire, sometimes with a core other than air. If the frequency of the signal is in resonance with the physical wires of the coil, the coil may vibrate. Oft times, the vibration is beyond human hearing (yokes in TV's can do this), other times it's in the range of human hearing.

There are many electrical parts/circuits which can cause whining noises, so don't just assume you are hearing coils. "Annoying buzzing/electrical sound" are unlikely to eminate from a coil - you have something else making noise. Whining is caused by a part (or parts) physically vibrating.

Unto itself, voltage is not going to cause a whining sound. Voltage is electrical potential (actually, EMF); current through a device is dependent on the voltage across it. With a CPU, changing the voltage probably changes the operating frequency of various components within the processor (I really don't know what is changed), however something is probably in resonance with the signal. If you can narrow down the source of the noise, you may be able to reduce or eliminate it. Try using the paper tube from a roll of paper towels to "listen" to various parts of your system to locate the source.

Good luck!

Wow that paper tube idea is ingenious!
Think I will try that tomorrow.

It's very difficult to isolate that noise.

 

[mpilchfamily]

Even if you isolate the noise you won't be able to fix it. Though it is good to narrow it down to a single component so it can be replaced. But don't exspect to solder a new coil or other part to remody the problem. But many things can cause an auto reboot. Sure the PSU is very suspect in this reguard but we are not limited to just that item as being the source.

There are plenty of infured and 900Mhz wireless head sets out there that have much better sound quality and range then any BT set will have.

 

[nineball9]

One way to fix coil whining is to use a hot glue gun and glue the loops together. Paraffin works better, is less likely to damage any parts and is easier to remove than hot glue. Mfgr's use paraffin but most hobbyists don't have it in their toolbox. I've used hi-voltage putty - a bit of a waste to be sure - but I had it in my toolbox.

Obviously, if your CPU itself is buzzing or whining, your options are rather limited.