Motherboard part identity(what the heck is it?)

Monkey34

Monkey34

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What the heck are these called( donut shaped with heavy copper wire wound on exterior)? I have one on a motherboard that was minorly damaged (then repaired), that I would RATHER replace than leave on the board.
 
Thought those were something like ferrite chokes or something..
 
awdark said:
Thought those were something like ferrite chokes or something..
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Pretty much the same thing. They're inductors. If it's broken, you might be out of luck. As far as I know, they aren't generally stamped with a value. They are measurable though, but only if they're not broken.
 
yeah, call and ask the manufactuers tech line and ask how many henrys those are. I would be interested to hear the answer.
 
I wouldn't be surprised if the people at the call center would have some trouble with a question like that.

There are formulas for calculating inductance based on core material, dimensions, and # of loops of wire. I don't know what they are, but I bet google could find you them.

How was it damaged and repaired? Was the wire just nicked, or what? As long as the core is fine you could rewind the inductor with the same number of turns and it would be have the same value as before.

edit: I can't really tell from the pictures, but are the other inductors the same? ie, same number of loops of wire and same dimensions of the core? If so, if you can get someone you can borrow an LCR meter or O scope from then you could find the value of the inductor and easily buy a replacement.
 
was gonna mention what matt said, take off one of those other inductors and get a measurement of the value of it. will need an oscope though. i've measured the values with a voltage meter before in a lab, but i remember it not being a very fun process.
 
Actually, the ones in the picture are just for illustration. The real motherboard has only one or its kind. The damage is only to the winding on one side....the core is intact. I actually found someone who make these, and he said he'll either send me some winding free of charge, or do it for $5. I found this site: Elecraft
and his order form is here: Toroids

I am going to de-solder it from the board, and send it to him to rewind.
 
Why don't you just rewind the toroid yourself?

Just get some magnet wire of the appropriate thickness (same size or slightly bigger) and make sure the number of turns is exactly the same.
 
Why don't you just rewind the toroid yourself?
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For the same reason I did'nt bother converting an AT power supply to an ATX after working on the schematic. Lack of component supply primarily.
 
Monkey34 said:
For the same reason I did'nt bother converting an AT power supply to an ATX after working on the schematic. Lack of component supply primarily.
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Doing an AT->ATX conversion is hard and not even worth the effort; you need to add a 3.3V rail, remote turn-on circuitry, a 5VSB power supply...

Rewinding a toroid involves pulling the existing wire off the toroid while counting the # of turns, getting some magnet wire, wrapping the correct # of turns on the toroid, trimming the wire and stripping the insulation off the ends of the wire, and you're done!

We hand-wind toroids all the time here at work...
 
Doing an AT->ATX conversion is hard and not even worth the effort; you need to add a 3.3V rail, remote turn-on circuitry, a 5VSB power supply...
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I know.
Rewinding a toroid involves pulling the existing wire off the toroid while counting the # of turns, getting some magnet wire, wrapping the correct # of turns on the toroid, trimming the wire and stripping the insulation off the ends of the wire, and you're done!
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I know.
Like I said, its lack of component supply. I'm lucky if I can find a resistor around here. I gotta start dumpster diving for circuit boards, so I can salvage the parts.
 
How was it damaged? Anything but a complete sever in the wire should not realy harm it's opperation that much.
 
How was it damaged? Anything but a complete sever in the wire should not realy harm it's opperation that much.
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Uh........a complete sever. :D
 
Monkey34 said:
I know.

I know.
Like I said, its lack of component supply. I'm lucky if I can find a resistor around here. I gotta start dumpster diving for circuit boards, so I can salvage the parts.
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order off the net...

for me, it used to be so hard to find electrical components and i used to rely and get ripped off by radio shack but after a while, i realized, you can get stuff on the internet

jameco, etc
 
wayne said:
order off the net...

for me, it used to be so hard to find electrical components and i used to rely and get ripped off by radio shack but after a while, i realized, you can get stuff on the internet

jameco, etc
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Things like those toroids aren't easily ordered... it's best to use the existing core if it's still intact and wind new wire on it.

You'll need to find out what material the core is made out of (MPP, sendust/kool-mu, iron powder... chances are it's sendust), the permeability and the exact dimensions of the core. All of these determine the inductance, and in a multiphase power supply the inductances have to be very closely matched.

If the wire is completely severed, can't you just sand a bit of insulation off the wire and solder the wire back together?
 
If the wire is completely severed, can't you just sand a bit of insulation off the wire and solder the wire back together?
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There's no insulation.......its bare, and yes I HAD soldered the thing together, and it posted, but I would feel better replacing it. Especially since I will be gaming on it, and probably o/c'ing it.
 
You will be fine just soldering it. A good solder joint has plenty of structural as well as electrical integrity. You may feel better if you replace it, but it'll be fine with just a solder repair.
 
gee said:
Things like those toroids aren't easily ordered... it's best to use the existing core if it's still intact and wind new wire on it.

You'll need to find out what material the core is made out of (MPP, sendust/kool-mu, iron powder... chances are it's sendust), the permeability and the exact dimensions of the core. All of these determine the inductance, and in a multiphase power supply the inductances have to be very closely matched.

If the wire is completely severed, can't you just sand a bit of insulation off the wire and solder the wire back together?
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i didnt mean toroids specifically... he mentioned resistors so i meant electrical components in general
 
jameco, etc
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Thanks for the site......I'll keep it for the future.
You will be fine just soldering it. A good solder joint has plenty of structural as well as electrical integrity. You may feel better if you replace it, but it'll be fine with just a solder repair.
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Your probably right, but I figure for $5, a fresh re-wind is worth it. Besides, the case is in the middle of a mod, and isnt ready yet, so I've got the time.
 
I personally think rewinding it could screw it worse than what he has already done. Don't the size of wire and diameter of windings both effect the henry value and resistance also? If it is realy effected by soldering it most likely won't be much. If it works with the solder, then it works. Most people would have tossed the board by this point anyway.
 
The diameter of the wire will affect the resistance, but not the inductance. Inductance is determined by the core material, dimensions, and the number of turns of the wire.

And the resistance of these things is hardly critical, the length of wire necesary to produce whatever number of turns the inductor originally will have a very low resistance regardless of whether he uses 24 guage or 12 guage wire, although fitting 12 guage wire around a typical motherboard inductor would be quite an impressive feat.
 
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