Plug whine

[Jasp]

Found this in both my HDX transformer that tends to "click" when the hard drive is accessed, bit weird really and my cousins ATI 4890 that tends to whine under high load.

[peterb]

I thought that some people used a rectifier, then a resistor to get a voltage drop, before going into a standard regulator.

Then again i've never looked at a mobile phone charger, but its certainly a cheaper circuit for very low power devices!

Not a good idea on domestic equipment - simplest method is a resistor and a zener diode, but that is inefficient (power dissipated in the resistor - and if it is dropping 230 volts, even at 10mA that is 2 watts. However it is dangerous as there is no mains isolation - neutral goes straight through - and if the input is reversed, it will still work, but now line goes straight through Ouch!

How did you manage to type all that without mentioning magnetostriction Peter?

It was difficult! (but I rose to the challenge ))

Found this in both my HDX transformer that tends to "click" when the hard drive is accessed, bit weird really and my cousins ATI 4890 that tends to whine under high load.

That is likely to be a noisy cooling fan kicking in under high load.

[Haiku32]

All this is going straight over my head, so long as my plug won't blow up then you boys enjoy your discussion about electrical nonsense .

[Jasp]

Peterb, you mean the transformer or the GFX card? the GFX is defo not the fan as it makes the whine when gaming and the fan is still on 25-30% its like a fast high pitched buzzing that changes depending on how stressed it is, eg a empty game area it fades and comes back in a populated area, its done it since it was brand new in the PC, me cousin didn't even notice but i have a ear for these things lol.

As for the transformer its actually off the laptop on the floor and only seems to do it under high HD activity, mostly writing.

Neither has blown up yet so im content to let them be lol.

[peterb]

y component, or it could be interference - Jasp, interesting! The card could have a noisy component or it could be interference generated by the card under load being radiated to the audio system - hard to tell without being there.

The laptop transformer could be something flexing with the current pulses as the the drive heads move, but again, without being there is is hard to make a definite diagnosis.

As you say, if it is working, leave it be!