mosfet heatsink installation

I'm looking to cool the mosfets on my 8rga+, i have an old intel chipset heatsink i cut up and lapped down... i was all ready to put the heatsinks on, but i noticed that there are 3 coils of wire or something next to the 6 mosfets.

what i need to know is, do those coils carry voltage?i dont have a multimeter to test them. the heatsinks will touch the coils. i can cut the heatsinks to fit... but i'll lose 1 row (12 fins outta 48)..

thx in advance

you know what....

Ill be honest i have absolutly no idea... however i do happen to have a multitester. So i will give it a shot on an old motherboard of mine to see if those coils do carry current.... It actually an interesting question... However i would assume that they do not actually carry current because it would seem weird that they would put open un-insulated coils on any piece of electronic equipment.... Talk soon... my aim name is fulloferik hit me up

OptPrime

I believe they do actually.

Those coils most likely do carry current and do have some voltage with respect to chassis (ground). They are part of the power filtering on the motherboard.

You might be able to use a piece of thin, tough plastic or some other insulator and not have to cut the heatsink, but I'd definitely insulate the heatsink from the coil(s).

These items found on almost every motherboard are power filters.

That's a really basic name for them, they are techincally known as:

Chokes, Inducters or simply Coils.

They serve a purpose to remove splurious signal from the power, and as they are generally close to memory and CPU sockets then it would be a valid assumption that they are required to provide a clean supply to those parts.

They are not bare wires, they are generally covered with a very thin layer of enamel, thought this layer is very easily chipped or scraped off.

I suspect that each of these coils would carry the main power rails, so they could be -5v, +5v or +12v BE CAREFULL NOT TO SHORT THESE OUT.

Also for your own info the mosfets have a small tab on the top of them, this is connected ellectricaly to the middle (center) pin.

Be careful not to short the tab to any other part of the mobo.

If you are concerned about heat dissipation frm the Fets, then try using a non-conductive spacer or heat spreader on the REVERSE side of the mobo, so it contacts the underside of the PCB and then contacts the inner side of the Base unit side panel. This will help spread some of the heat away from the mobo into the case.

I do something similar on all my Graphics cards, have you ever felt how hot they get on the opposite side.. heat travels in ALL directions not just to the heatsink. I use insulated stickers to cover the exposed solder joints then apply a heatsink.. this then dissipates heat from both sides of the card and not just from the usual side.

One othe rpoint about cooling is air pressure, I did extensive research towards this back in 2000, and the aim of any overclocker should be to balance the air pressure.. too high or too low will result in a drop of efficiency.

Good call Ashfield, I forgot to mention that the coil wire is normally covered with a thin layer of clear enamel. The trade name for this wire is magnet wire and is what they use for winding transformers, etc.

Those coils DO carry voltage and if I remeber right from electronics classes(years ago so don't qoute me please) they act much like a transformer and either up amperage and lower voltage or up voltage and lower amperage. They can do either if Im thinking they are what I think they are.

slightly incorrect, although the base design of any choke, inductor is very similar to a Transformer, for a transformer you need a ferrite centre or bobbin.

Most of th eones I find on mobo's seem to have ceramic centers, thus making them inductors or chokes.

These do not alter the voltage or current, but clean it!

They remove RFi interference and RED Noise which is digital line noise.

To complete a Suppression circuit you need Inductors and Capacitors.

The coils can also be used to Balance the operation of Transistors or FETs, much like in any dual switching arrangement.

This is called Biasing.

I have an old slot 1 mobo I just looked at here and the only two on the whole board are used for Biasing, on another board they are used for both Biasing and Filtering of the supply.

Hope this helps, but the basic thing is try not to damage the enamel and short them out to anything.. KABOOM!