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Thread ID: 57702 2005-05-10 06:48:00 How to get these evil things apart george12 (7) PC World Chat
Post ID Timestamp Content User
353838 2005-05-11 02:25:00 If it's an epoxy I have come across a product called "Desolv" (I think) which will zap it.

In recent articles about modifications to computer power supplies, the suggestion was to use methyl chloride paint stripper, soaking overnight.

Both would almost certainly destroy the enamel on the windings.
Graham L (2)
353839 2005-05-11 05:18:00 I want to reuse some winding wire, so... Hmmm.

I guess I could remove the wire (not without some difficulty) then try baking.

I'm using two paralleled (more for heat dissipation reasons) IRFZ46 mosfets each rated for 50 amps each per side. At the low end of the voltage rating each will be passing about 28 amps. But it's not usually like that for long. Most commonly it would be just while cranking in a car.

When at 12V they pass 17 amps each.

The 5v rail of this transformer is rated at 40 amps IIRC, so one or two times that should do the trick.

Thanks for the help. I'll now remove the windings and try some things. Actually, I'll do it on an identical (core-wise) but not important transformer first!

George
george12 (7)
353840 2005-05-13 03:31:00 Don't design for 7-20V input . Your car alternator should not give any more than 14 . 4V . It would cook all the accessories if it did . You shouldn't run your car battery lower than about 11V (if you don't want to destroy it) . A deep cycle battery shouldn't be taken lower than 10V or so --- most commercial inverters cut out at 10 . 5V .

If your car battery drops to 7V when starting, it will sag even more if you are trying to pull an extra 400W or so . The engine won't start .
Graham L (2)
353841 2005-05-14 00:00:00 Wouldn't you better to go for a native Mini ITX/EPIA setup that runs natively at 12 volts?

Or buy an inverter/proper power supply?

I just can't see this ending well :-(
ninja (1671)
353842 2005-05-14 02:01:00 I'm all for experience, and boy oh boy would I love the time to build a motherboard from spare parts - but reinventing the wheel in my experience has caused nothing but pain, trouble, and has been nothing but a waste of time.

Having said that, good luck :).
Growly (6)
353843 2005-05-14 03:18:00 I've made a test transformer out of spare stuff (an old core that wasn't glued with that evil stuff) and it's going pretty nicely. I'm happy with how it's going, so I can't see your worry ninja.

I make things like this more because I want to than I need to run a PC in my car. I fact, I don't want to run a PC in my car, and I certainly don't have any that draw 400W. I just want to make it :).

Thanks for the suggestion Graham, I might narrow that range a bit.
george12 (7)
353844 2005-05-14 03:25:00 The trouble is that power FETs and transistors are much faster fuses than fuses. They ought to be: they cost more. ;) Graham L (2)
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