safe to run power supply without fan?

J

jabboo

Guest
would it be alright if I took the fan out of a 200w power supply ?
its an old computer power supply the AT kind
im going to cut all the external connectors off it and only leave a +12v
wire and a ground wire
so I can use it to supply power to a circuit which uses about 1.6amps
without it overheating ?

also another question
would there be much voltage drop if I run the 12v over a 3m length of cable
? carrying the 1.6amps

--
Anthony Jabbour
 
go buy a 12v downlight transformer and wire in a big bridge rectifier with
heatsink, it'll give you 4 amps, thermal overload protection and peace of
mind.

"jabboo" <jabboo@(nospam)optusnet.com.au> wrote in message
news:3f3e0e52$0$15130$afc38c87@news.optusnet.com.au...
would it be alright if I took the fan out of a 200w power supply ?
its an old computer power supply the AT kind
im going to cut all the external connectors off it and only leave a +12v
wire and a ground wire
so I can use it to supply power to a circuit which uses about 1.6amps
without it overheating ?

also another question
would there be much voltage drop if I run the 12v over a 3m length of
cable
? carrying the 1.6amps

--
Anthony Jabbour
Click to expand...
 
"jabboo" <jabboo@(nospam)optusnet.com.au> wrote in message
news:3f3e0e52$0$15130$afc38c87@news.optusnet.com.au...
would it be alright if I took the fan out of a 200w power supply ?
its an old computer power supply the AT kind
im going to cut all the external connectors off it and only leave a +12v
wire and a ground wire
so I can use it to supply power to a circuit which uses about 1.6amps
without it overheating ?
Click to expand...
Many of these supplies won't even start up without a substantial load on the
5V. Might run without the fan, might not. buy a 12V plugpack & be done
with it.

also another question
would there be much voltage drop if I run the 12v over a 3m length of
cable
? carrying the 1.6amps
Click to expand...
This depends entirely on the resistance of the wire (determined mainly by
material and cross sectional area). Bugger all over some jumper cable,
probably a few volts over some wire wrap wire.
 
I also had this problem a couple of months ago. I wanted to build a good
quality car sound system into a bedhead and needed a 12v supply with some
half decent current so I used an old AT power supply which provides around
8-12amps I think. I wasn't too sure about not having a fan at all but was
concerned about the noise it would produce in the dead of night so I used a
resistor on the fan supply to slow it down to the point where I couldn't
hear it but it would still provide cooling. Works like a charm. Now my bed
rocks :)
Chris


"jabboo" <jabboo@(nospam)optusnet.com.au> wrote in message
news:3f3e0e52$0$15130$afc38c87@news.optusnet.com.au...
would it be alright if I took the fan out of a 200w power supply ?
its an old computer power supply the AT kind
im going to cut all the external connectors off it and only leave a +12v
wire and a ground wire
so I can use it to supply power to a circuit which uses about 1.6amps
without it overheating ?

also another question
would there be much voltage drop if I run the 12v over a 3m length of
cable
? carrying the 1.6amps

--
Anthony Jabbour
Click to expand...
 
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