High pitched hum from electronics

[randay]

Im very sensitive to the sound, high pitched tones like the mosquito ring, or the sound a TV makes. I've even had problems with it from a barbeque, apparently the propane flowing out of the tank made a high pitched tone, its really peircing and it agitates my hearing. What causes this sound in electronics? I'm guessing capacitors? If a computer is making this sound, does it mean that some of the electronics is malfuntioning?

 

[ATLien247]

AC filter?

 

[So]

Capacitors? <giggle>

It's any high frequency signal -- usually it's from CRTs that use a flyback transformer.

 

[randay]

Originally posted by: So
Capacitors? <giggle>

It's any high frequency signal -- usually it's from CRTs that use a flyback transformer.

But its coming from a computer right now, either the PSU or motherboard, and when I manually short the PSU on I dont hear it, but when I plug it all up and turn the computer on I do.

 

[daveshel]

oscillators

 

[Rubycon]

Many electronic circuits employ oscillators at frequencies in the range of 4kHz to 90KHz and beyond. The 15.734kHz whine (15.625KHz if you live in the UK )you hear from the TV is caused by discrete parts in the signal path moving slightly and acting as a very high frequency transducer. Components with thin metalized coatings make an efficient transducer with rapid attack and decay response and will easily excite with a relatively low amount of bias. Some folks' ears are more sensitive to this than others.

Noises don't necessarily indicate a malfunction however there is usually a product to product deviation where two identical models can produce it or not.

 

[Shame]

Flux capacitors.

 

[Canai]

I dunno but the laptop next to me has been emitting a horrid whine for several days now.. good thing it's not mine

 

[randay]

Originally posted by: MS Dawn
Many electronic circuits employ oscillators at frequencies in the range of 4kHz to 90KHz and beyond. The 15.734kHz whine (15.625KHz if you live in the UK )you hear from the TV is caused by discrete parts in the signal path moving slightly and acting as a very high frequency transducer. Components with thin metalized coatings make an efficient transducer with rapid attack and decay response and will easily excite with a relatively low amount of bias. Some folks' ears are more sensitive to this than others.

Noises don't necessarily indicate a malfunction however there is usually a product to product deviation where two identical models can produce it or not.

Thanks, is there any way to reduce the noise? I am pretty sure it did not do this when new.

 

[ryan256]

Originally posted by: MS Dawn
Many electronic circuits employ oscillators at frequencies in the range of 4kHz to 90KHz and beyond. The 15.734kHz whine (15.625KHz if you live in the UK )you hear from the TV is caused by discrete parts in the signal path moving slightly and acting as a very high frequency transducer. Components with thin metalized coatings make an efficient transducer with rapid attack and decay response and will easily excite with a relatively low amount of bias. Some folks' ears are more sensitive to this than others.

Noises don't necessarily indicate a malfunction however there is usually a product to product deviation where two identical models can produce it or not.

I thought it was something like this.... my Antec PSU is doing the same. Emits a very high pitched whine that gives me a headache after a while. I was considering getting an RMA on the thing and swapping it out. Thing that might help or would the next unit be likely to whine as well?

 

[Oblivionaire]

Pour a whole bottle of gorilla glue all over the components.

 

[Rubycon]

Originally posted by: randay

Thanks, is there any way to reduce the noise? I am pretty sure it did not do this when new.

In the old days when a B&W Monkey Wards "Airline" brand TV (Made by Sharp BTW) whistled, a crack on the side with a high heel stopped the whistling for a while and it slowly crept back. I don't recommend you beat up your power supply but going at it shouldn't do it in.

Originally posted by: Oblivionaire
Pour a whole bottle of gorilla glue all over the components.

Potting compound may reduce but will not eliminate the sound. I have potted power supplies running various things like video amps and baluns and inductor sing can be heard if the supply is held near the ear. Granted it would probably be noticeably louder if open.

GG is a urethane based adhesive. It expands like crazy. I have an old Gateway dual Pentium Pro Server that was taken out of service. It whistles like crazy and I should pour some of this stuff all over it to see what happens. Scary what those 1MB L2 200MHz CPU's cost in the day and the gold in the pins is worth more than they are now. :Q

 

[Oblivionaire]

Originally posted by: MS Dawn
Potting compound may reduce but will not eliminate the sound. I have potted power supplies running various things like video amps and baluns and inductor sing can be heard if the supply is held near the ear. Granted it would probably be noticeably louder if open.

GG is a urethane based adhesive. It expands like crazy. I have an old Gateway dual Pentium Pro Server that was taken out of service. It whistles like crazy and I should pour some of this stuff all over it to see what happens. Scary what those 1MB L2 200MHz CPU's cost in the day and the gold in the pins is worth more than they are now. :Q

Ooo awesome let us know what happens if you decide to do it. I wish I had some whiny device to pour it on and see if it works or not.

 

[ryan256]

Hmm.... something interesting I just found out. My PSU that whines is made with fuhjyyu capacitors. The same ones that have been notorious for busting at 45c and spilling fluid all over the place. I'm wondering if thats a contributing factor.

 

[Night Blade]

I have a Sparkle 400W power supply that does this if I plug in a SATA drive, bloody irratating. My 15 year old Sony 26" CRT does this aswell, is there anything I can do to fix this?

 

[randay]

Originally posted by: Night Blade
I have a Sparkle 400W power supply that does this if I plug in a SATA drive, bloody irratating. My 15 year old Sony 26" CRT does this aswell, is there anything I can do to fix this?

oh, the psu im talking about is a sparkle too! a 300w. hrmm.

 

[Rubycon]

Originally posted by: ryan256
Hmm.... something interesting I just found out. My PSU that whines is made with fuhjyyu capacitors. The same ones that have been notorious for busting at 45c and spilling fluid all over the place. I'm wondering if thats a contributing factor.

Oh what a big disgrace!
Them Fuhjyyu's be 'jaculatin'
All over da place!

 

[JulesMaximus]

Originally posted by: Canai
I dunno but the laptop next to me has been emitting a horrid whine for several days now.. good thing it's not mine

Bang it on the table until it stops.

 

[LanceM]

Powered by bees.

 

[ryan256]

Originally posted by: MS Dawn

Originally posted by: ryan256
Hmm.... something interesting I just found out. My PSU that whines is made with fuhjyyu capacitors. The same ones that have been notorious for busting at 45c and spilling fluid all over the place. I'm wondering if thats a contributing factor.

Oh what a big disgrace!
Them Fuhjyyu's be 'jaculatin'
All over da place!

Hehe... tell me about it. So far we've had to get Dell to replace nearly 200 motherboads because of it

 

[Gibson486]

feedback....it when a circuit has to much gain due to amplifying another circuits noise.

 

[Gibson486]

feedback....it when a circuit has to much gain due to amplifying another circuits noise.

 

[Cattlegod]

Sound 2kHz+ is almost all airborne. If you plug all the holes in your unit, that should solve the issue. Though, the TV may overheat as a result. You could also put some mastic or some material to dampen around the area where the board mounts to the TV.

 

[richardycc]

I had to return a samsung plasma tv becuz of the high pitch noise.

 

[randay]

Ran down to compusa and picked up a new PSU, problem solved. It still emits a hum but its about 95% more bearable then before, don't know if it is less intense or a different frequency, but as long as it isnt scratching my brains out Im happy.