DC Voltage regulator

xhunter911

Hello all,

I am looking to build a small varible voltage regulator that I can control from the inside my vehichle, that will allow me to control the voltage of my 320 Amp Leece Neville stand alone alternator... Currently I use this alternator to power my amplifiers that will handle up to 20VDC. I also have paralleld (2) 8 volt batteries to make the equipment run on 16VDC instead of 13.8... Does anyone have simple schematics on this???

Any help or any suggestions will be appreciated...

berkeman

First, you have series'ed th two 8V batteries to make 16V, not parallel'ed.

Your requirements are for Vo = 20Vdc max to some Vmin, at 320 Amps?

Danger

Xhunter, do you have any eardrums left?

xhunter911

I think berkeman knew what I ment...

I just want to some input on building a voltage regulator...
If you guys cant help me thats ok...

I currently build 10 meter amplifiers and Big DC unregulated power supplies from 50Amp up to 400Amp, so I would think that this regulator would also be quite simple to build for a beginer like myself....

thanks

NoTime

Same topic in this

http://www.physicsforums.com/showthread.php?t=138477

might help.

Danger

I can't help you; I don't know anything about electronics, but that was a serious question (badly worded, perhaps). There have been a lot of official warnings up here about kids going deaf in those rolling boom-boxes. Just how many decibels are you pushing there, anyhow?

xhunter911

Im not running class D amplifiers, I am running class C amplifiers with close to 10KW (pep)...

berkeman

10m amplifiers...you a HAM? Good stuff! A voltage regulator in the power range you are talking about is just like a follower amp, with the input being the desired output voltage (plus a diode drop). You can parallel up several power BJTs to supply all that current, and each emitter has a small series resistor to help balance out the output currents and prevent current bunching in one runaway BJT. Does that make sense?

Danger

Oh, okay... that makes more sense. I thought that you were driving a sonic weapon around.

xhunter911

I am a Ham, and I also sometimes fool around on 11Meters too... I understand what you are saying, but without a visual I get lost....
I am truly sorry for my stupid questions, but I have to learn more somehow, and why not from the masters... Here are a few of my projects that I have completed...

berkeman

Your questions are not stupid, and your project pictures are very nice. Here's the wikipedia article on voltage regulators for background info:

http://en.wikipedia.org/wiki/Voltage_regulator

The bipolar follower arrangement that I mentioned is shown in the Linear Regulator part of that article, about half-way down the page. They show it with just one NPN BJT (bipolar junction transistor), but you can parallel up multiple BJTs to increase the output current capability, as long as you put a series emitter resistor in with each of the BJTs. The Re should be sized to give you about 0.1V voltage drop at full current.

xhunter911

I think I get it... I will be testing it out this weekend.... Thanks berkeman!!!

I will keep you posted...

xhunter911

Berkeman here are the photos

berkeman

That's not a 320A power supply. Could you please clarify what it is/was, and what you are trying to do with it? Even if you're only dropping 3-4V in the regulator, that's about a kW of power that your 320A power supply would have to dissipate. That means fans and lots of metal heat sinking....

Ouabache

If I am understanding your specs correctly, it seems you are just wanting a Vdc supply to operate at a voltage higher than your battery, used for an amplifier 10KW (PEP) for your 10m Xmtr. [I assume the output power on your amplifier was a typo. You probably recall, the maximum allowed power (if you are licensed in U.S.) on 10m amateur band is 1.5KW (PEP). How about using your car battery (12V) and stepping up the voltage to your requirement using DC-DC converter? Then you won't need to rectify the AC voltage and handle 320A from the alternator.