300 amp power supply

I've done 5V/400A. I suggest you buy one off-the-shelf... it's not a task for beginners. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Litz wire inductors, gets expensive for one offs.

Cheers

Many years ago I learned the hard way... melted bobbins... 9th harmonic presents significant power dissipation... switched to Litz.

(I used copper tape for the output winding.) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142     Skype: skypeanalog  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
I love to cook with wine.     Sometimes I even put it in the food.

Beside buying one.what is the better technique?

Jim. How much would you ask for your 400A plans?

I'm not sure I even have them... it was 1977, a project for ADR Ultrasound... and I'm sure there are better ways now... there were no switcher-specific chips then. ...Jim Thompson

-- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 | I love to cook with wine. Sometimes I even put it in the food.

Only $5,860. Ouch.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Buy the inductors from Coilcraft. Use a polyphase buck, as long as the

18 volts doesn't droop too much.

Still, this won't be easy.

That's just for supplying the 18v 300A to the input. If the load is fairly constant, and there's a common ground between input and output, it might be possible to use a 0.01 ohm series resistor from 18V to 15V at 300A. Regulation would be lousy and you would need to do something with the 900 watts of heat, but it sure would be a cheap way to lose

3V DC.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Im not sure coilcraft has inductors to handle that much current. Ive used their coils for sepic projects. But never more then 10 amps. Now 300amp is a whole different story.

Hi i need a very stable and accurate 15v.. Not sure just a resistor will do

On Fri, 18 Sep 2015 19:30:22 -0700, Jeff Liebermann Gave us:

Notice that his is not a line driven PS, but a DC to DC converter.

A polyphase switcher shares the current among multiple paths, usually

2 to 4. That has huge advantages.

You could also parallel smaller inductors. Eight inductors in a

4-phase switcher is only 38 amps each, which is in the Coilcraft sort of range.

I think LTC has some polyphase switcher controllers.

Still, it's going to be a challenge.

What do you need the 15 volts for?

On Fri, 18 Sep 2015 19:45:01 -0700 (PDT), captoro Gave us:

Use car batteries..

Even a mall change DC to DC converter like that which you describe will not get you what you are after. It might end up at 15V but when loaded up at your mentioned current level, it would exhibit several types of noise compared to actual DC sources. You are going to have a hard time getting to your goal if pure DC is in order . "Stable and accurate" is actually a pretty vague 'moniker' where power supplies are concerned, even DC-to-DC converters.

Hell, banks of 13 rechargeables in parallel with a small (small value, not small size) tail end dropping resistor would be cleaner.

1.2 x 13 = 15.6 Have several banks of those. 3.7 x 4 = 14.8 and they are usually a little hot after a fresh charge, so a "battery" built from banks of those would be stable until they reach their avalanche point. And very close to 15 volts.

My client didnt tell me. Its a battery place. Actually he needs 14.5v not 15v. So maybe its for charging batteries. Just left a message on my voicemail

Take a look at Miller DC inverter welder power units. They are right in you range of voltage and current.

They use IGBTs.

Miller uses 120v or more on the input..not same approach. Sepic converter wouls be great if doable because i can have programmable chip verifying the output voltage and can make adjustments while powered to have a steady output voltage

Yes, you are right. I read it wrong also.

That's why John said to use a polyphase buck. The only issue is current sharing. I've used CoilCraft inductors to ~30A. THe SER2918H series are quite good and not insanely expensive.