Any suggestions for regulating 16volts down to 13.8volts?

As per the title.

Needing about 100amps.

I was considering a switchmode controller, maybe a 494 or 3525, eight mosfets, most likely Z44's, and a transformer, maybe even a 1:1 ratio. Plus the associated components of course.

But I'm wondering if there's an easier way? More efficient maybe?

Thanks!
 

FoMoCo

Member
2012-12-04 10:04 pm
Fine... This is the last I'll help you.

Assuming you're feeding an amplifier, you don't need to regulate it.

In that case... Just change the existing primary turns on the amp's transformer's primary to 16/13.8 times the existing number (most likely adding a turn on each side of the centertap will do it). Bam! 16V amp. Just make sure the input side control circuitry can handle 16V.
 
You need a regulator able to go down to 0.022 ohms and dissipate 220W (if linear)

A linear regulator with several low Rds FET's would work. (not efficient)

Transient response (stability) is going to be the interesting part.

PWM regulators might be an idea for this level of current...chose the inductor carefully...more efficient

Sound like an excellent challenge...wish I had more time.

:)
 
It'll have a battery across it, so ripple/stability shouldn't be a problem.

Its basically needed to replace the alternator in a car that has a higher voltage alternator fitted, and a "16volt" battery bank (that'll be charged at about 18.4volts)

100amps +-20amps is the idea, along with the stock 12volt battery.

Needs to be able to run all the stock electrical, plus maybe 400watts worth of amplifier.

Switchmode was the idea because its also easy to turn it off when the keys are off, as most switchmode controllers have an on/off pin ;)

Had a look for a buck converter using a 3524 and an inductor, that could be beefed up, but can't find anything that really looks suitable, and not sure where to start..