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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



4 years ago

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 !!!

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

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


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


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.

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.


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