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Post by Dave on Feb 19, 2004 21:11:43 GMT 8
Neil
Any suggestions on where to find a regulated variable power supply (0-24v, 10A) for cheap? (incl. 2nd hand).
Is it possible for someone 'like me' to build one?
cheers..
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Post by neil on Feb 19, 2004 22:03:53 GMT 8
they don't make em that beefy dave.
variable 0-24V at 1 amp is possible
I'm assuming your after something mains-powered
for 10A at 3.3 or 5 or 12V you can't go past a $1 old at or atx computer power supply. rewind it and it will give you any one voltage at 10A (quite involved)
whats it for?
you'll probably find if it's a motor control or etc then varying the power supply isn't the way to go, but use a fixed supply and a PWM switching scheme or something
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Post by Dave on Feb 20, 2004 10:51:53 GMT 8
Ta Neil
is the rewinding just a change in the windings ratio?
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Post by neil on Feb 23, 2004 0:15:43 GMT 8
no, it's involved  gotta remove sections of the circuit for other voltages, modify other bits, rewind transformer, etc it's in a magazine, have a look if you like hmm platinum plugs $50 each well at a nissan dealer anyway  $400 doesn't cover the good oil either - extra. any other reliable places you recommend? |
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Post by Dave on Mar 1, 2004 22:25:10 GMT 8
hey Neil I've just built myself a (very small) vacuum former. If ya want any of your small circuits packaged in a plastic case or something let me know (max. size 150mmx100mm). I'm also chasing a circuit diagram for a drag racing 'Christmas tree' using LEDs, y'know the lights that go RED, ORANGE, ORANGE, ORANGE, GREEN with 0.4secs between each orange and the green light. The start signal would have to trigger the 1st orange I s'pose. I dont think I'll worry about staging lights just yet.  |
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Post by Dave on Mar 1, 2004 22:29:07 GMT 8
oh btw
I spent ther past week driving around in a KRS13 180SX that I picked up for my dad. Only had the CA18DET in it but incl a full HKS exhaust. Went rather nicely.. dunno if the HICAS works or not though
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Post by neil on Mar 2, 2004 22:27:13 GMT 8
did you use a vacuum cleaner? hehe
could build a circuit, hmm maybe use a 4017 and a 555.
riding on the weekend?
i'll draw you a circuit if so
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Post by Dave on Mar 2, 2004 22:36:34 GMT 8
ewll, actually the vacuum does come from my vac cleaner....
hopefully riding this w/end ;D
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Post by Dave on Aug 9, 2004 20:16:39 GMT 8
hahahaha
yet another tech quiz for you Neil
figured out the input power to SMPS, but I couldnt find any voltages on the DC outputs - d'ya reckon it might need a signal to turn on??
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Post by neil on Aug 10, 2004 15:01:13 GMT 8
yeah
can narrow it down by looking at where the tracks from the output connector go. careful cos the caps can stay charged after you turn it off and open it.
the main output and ground will have multiple connections on the output connector.
atx computer power supplies use an external open collector pulldown to turn them on (PSON). there is also a power good (PGOOD) wire, which signals if the psu output is ready for action. you might have similar signals, and then some.
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Post by Dave on Oct 26, 2004 21:46:32 GMT 8
hey thesis boy! for a simple common CE transistor circuit (DC), to find collector current should I do a loop analysis(KVL) through the base/collector for base current then use the gain to determine collector current? just in case you didnt have enough work to do ;D |
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neilatthesisvilleat2am
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Post by neilatthesisvilleat2am on Oct 27, 2004 2:05:55 GMT 8
yeah determine the base current then ic=beta ib.
to get base current you'll be doing ohm's law on the base resistor prolly, cos you can use KVL to figure out the voltage across that resistor. KVL on the gnd - source - resistor - base - emmitter -gnd loop, that is.
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neilatuniat3amthenextday
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Post by neilatuniat3amthenextday on Oct 28, 2004 2:39:15 GMT 8
why did the chicken cross the road?
to get to the 24 hour servo!
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