PARALLELING FIXED REGULATORS (SAFELY)

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Craig Kendrick Sellen
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PARALLELING FIXED REGULATORS (SAFELY)

Post by Craig Kendrick Sellen » Mon Sep 24, 2007 7:55 am

I NEED TO HAVE 6VDC AT 10 AMPS. I WAS THING OF MAYBE SEVERAL SMALLER IC REGULATORS IN PARALLELING THEM? OR IS THERE A 10 AMP. REG. OUT THERE? :???:

dyarker
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Post by dyarker » Mon Sep 24, 2007 8:16 am

A 15A transistor, or FET, controlled by one regulator?

Is source AC mains? A Meanwell switcher from Jameco might be best.
Dale Y

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jollyrgr
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Post by jollyrgr » Mon Sep 24, 2007 5:48 pm

I agree with dyarker. Use a pass transistor such as a pair of 2N3055 paralleled as a common base configuration. Unregulated voltage enters the COLLECTOR. The three terminal regulator gets its input voltage off the unregulated supply. Ground is ground or a "virtual" ground from a voltage divider. Output of the voltage regulator drives the BASE of the transistors. Output of the supply is taken at the EMITTER of the transistors.

Google "2N3055 Regulated Supply" (no quotes) to see some example schematics. There are multiple designs as this is extremely common.

I tried paralleling these three teriminal devices in the past with poor luck. The pass transistor method works best.

If you REALLY need a schematic posted, let us know.
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GoingFastTurningLeft
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Post by GoingFastTurningLeft » Wed Sep 26, 2007 2:37 pm

I remember a few months back I read in N&V that you should never hook up voltage regulators in parallel. They really don't like it, and they're always trying to balance each other out.

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haklesup
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Post by haklesup » Wed Sep 26, 2007 3:54 pm

At least some regulators are parallel capable, See these articals

http://www.edn.com/contents/images/6475014.pdf

http://electronicdesign.com/Articles/In ... cleID=9270

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MrAl
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Post by MrAl » Thu Sep 27, 2007 6:58 pm

Hi hackle,

I may have missed something, but i could not find the part number
of the regulator chip they were using in that second link. Any ideas?
LEDs vs Bulbs, LEDs are winning.

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Post by Robert Reed » Thu Sep 27, 2007 8:39 pm

Craig
Exactly what are the requirements of your supply in terms of REGULATION?

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haklesup
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Post by haklesup » Mon Oct 01, 2007 8:02 pm

MrAl, Most of page 1 was generic but page 2 throws around a few part numbers and figure 5 has one in the graphic

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MrAl
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Post by MrAl » Tue Oct 02, 2007 12:36 am

Hi again Hackle,

Ok thanks, i found some pics that seem to help a little.
I was a little disappointed however, in that many of the 'solutions'
were very 'partie' in that they used lots of resistors and perhaps a
few op amps. I was hoping for less parts.
The controller ic they showed was interesting though in that it can
drive low side *and* high side N-MOSFETS it seems.
LEDs vs Bulbs, LEDs are winning.

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