Some Computers and Mini-PCs have a fan mounted on their CPU/SoC, to cool it.
I know that motors produce high voltage back on their inut voltage wires, when they rotate,
(specifically each time the coil is being disconnected, during the turning of the motor),
so this makes me wonder:
A computer is a sensitive device.
Unlike a light bulb for example, it prefers a clean DC voltage.
So when a Computer/Mini-PC has a built-in fan, is there some protection circuit, to prevent the noise/high-voltage returning from the motor back to the computer's mother board?
Some Computers and Mini-PCs have a fan mounted on their CPU/SoC, to cool it.
I know that motors produce high voltage back on their inut voltage wires, when they rotate,
(specifically each time the coil is being disconnected, during the turning of the motor),
so this makes me wonder:
A computer is a sensitive device.
Unlike a light bulb for example, it prefers a clean DC voltage.
So when a Computer/Mini-PC has a built-in fan, is there some protection circuit, to prevent the noise/high-voltage returning from the motor back to the computer's mother board?
If yes, how is that circuit built, in general?
Thank you
I guess you have never examined a running computer circuit with an oscilloscope! Extremely noisy! That is why computer circuits are almost always synchronized with some type of clocking signal to make sure the signal for that device is only tested when the clock says to do it.
Most computer fans are DC operated with all the multi-phase circuitry built into the device. They generate no external noises. You are thinking of "brushed" motors.
Some Computers and Mini-PCs have a fan mounted on their CPU/SoC, to cool it.
I know that motors produce high voltage back on their inut voltage wires, when they rotate,
(specifically each time the coil is being disconnected, during the turning of the motor),
so this makes me wonder:
A computer is a sensitive device.
Unlike a light bulb for example, it prefers a clean DC voltage.
No, digital circuitry isn't very fussy, doesn't need to be very clean, just +/- 0.25V or so, the noise isn't a problem, but big spikes are.
So when a Computer/Mini-PC has a built-in fan, is there some protection circuit, to prevent the noise/high-voltage returning from the motor back to the computer's mother board?
Yes, of course.
If yes, how is that circuit built, in general?
Thank you
Ask a fan manufacturer? Reverse engineer one? Freewheel diodes are the obvious approach, very likely this is all on a single chip driver with built-in protection anyway.
MarkT:
No, digital circuitry isn't very fussy, doesn't need to be very clean, just +/- 0.25V or so, the noise isn't a problem, but big spikes are.
Hmm, nice to know.
So analog circuits are more sensitive to it.
MarkT:
Ask a fan manufacturer? Reverse engineer one? Freewheel diodes are the obvious approach, very likely this is all on a single chip driver with built-in protection anyway.
Well not sure a fan manufacturer will be approachable easily,
but the Reverse engineer one option is quite feasible.
So If I buy a CPU fan, or a PC Case fan, and disassemble it, there should be some minimal circuit inside?
(I was expecting the circuit to be on the motherboard instead of in the fan..)