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Need regulated 12v output to handle 70A

Need regulated 12v output to handle 70A

Need regulated 12v output to handle 70A

(OP)
I need a circuit that will take in 14 v and put out a regulated 12v with a max load of 70A for 4 minutes. Any ideas of what circuit I can make?

RE: Need regulated 12v output to handle 70A

A voltage regulator? There are many designs for low drop-out regulators out there. Which ones have you tried? 70A is a fair bit of current but not ridiculously high. Given the option a switch-mode type would have the lowest losses but dropping a couple of volts is certainly possible using a linear type if you don't mind a big heatsink and a fan (or a really big heatsink and no fan).
  

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If we learn from our mistakes I'm getting a great education!
 

RE: Need regulated 12v output to handle 70A

Difference between input and output is prety small, only 2V and have to supose that input voltage drop at full load will be very small.
Depending what mean "regulated" 12V - what % is allowed for application, one simple way and cheap is to put 2 or 3 series power diodes to obtain 11.9 - 12.4V output voltage. Large heatsink may be needed. If is not acceptable you'll need a converter, maybe with transformer 1:1 or even slightly higer to overcame this small input-output voltage difference and by PWM control to obtain a very stable 12V output.

RE: Need regulated 12v output to handle 70A

I wondering why/if you actually need a regulated 12V.

Most of the current consumers I can conjecture that have a nominal voltage of 12, are actually intended for use in automobiles, where the system voltage at which devices are expected to operate ranges between 8-ish and 14.5-ish volts.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: Need regulated 12v output to handle 70A

Dumb structural here - but wouldn't a big car battery work??  Or maybe a couple in parallel??

RE: Need regulated 12v output to handle 70A

Car battery voltage may be over 14 Volts at no load, and below 12 volts when partially discharged and under heavy load. 13>8 Volts has been a widely used full charge voltage for automotive batteries and I have seen higher settings.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Need regulated 12v output to handle 70A

At 70A , make sure wiring losses don't spoil your 2V !

RE: Need regulated 12v output to handle 70A

Many power supplies of this sort of current class would provide 'remote sensing' terminals to accommodate voltage drop in the cabling to the load.

What's the application?
 

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