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high current adjustable power supply? Answered

i want to run my ps2 in car,

Any circuit to drop 12v to 8.5V at 6amps
the lm317 circuit is not powerful enough

9 Replies

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mpilchfamilyBest Answer (author)2013-01-23
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iceng (author)2014-03-11

As Steve said .... BTW when running your car puts out 13.5 volts !

The Power Loss math is analog voltage drop times current.

Power = 13.5v - 8.5v x current = 5v x 6amp = 30 WATTS of HEAT !!!

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steveastrouk (author)2013-01-23

You're in Switcher territory, dropping 25 W is a lot to waste.

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ARJOON (author)steveastrouk2013-01-29

i came up with this on a datasheet
is it worth a try???
changing the transistor to achieve bigger current ?

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steveastrouk (author)ARJOON2013-01-29

It'll BURN with 25W of dissipation - the computer only takes 50.

Steve

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Thuringen (author)steveastrouk2014-03-11

No it wont. pass transistor/Regulator circuits at <10 amps float around 80% efficiency if the input voltage is selected properly. sure, switch-mode will be more efficient, but for cost, linear is hard to beat.

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steveastrouk (author)Thuringen2014-03-11

That's why reading the question is SO important

Any circuit to drop 12v to 8.5V at 6amps.

Which he illustrated with a linear circuit, and Lo ! it dissipates 21W, because THAT'S THE SPEC. He CAN'T select the input voltage. Yes, as a PE for the last 30 years, I am very aware of the benefits of linear regulators in the right places.

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iceng (author)steveastrouk2013-01-23

+1

We know, you know, a switcher is not a green wood sapling :-)

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