converting a 12volt ALTERNATOR to 24volt----BS2project

$WMc%

Hello All

I'm looking at converting a 12volt alternator over to 24volts. I can do this with some old school circuits,I was wondering if there was any modern ways to do this, And do it easily?

The ALTERNATOR RPM will be at least 3600rpm continuous

the LOAD will average 400 watts with sort term peaks of 1500watts (no more than 300mSecs)

Will use two 12volt 880 CCA/hr batteries in series.

the Load is two 600watt 24volt DC motors

I have a 100amp Delco that I plan to modify to 24volts.

Any new ideas would be greatly app.


_______________$WMc%_____________

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The Truth is out there············································ BoogerWoods, FL. USA

Post Edited ($WMc%) : 7/19/2009 11:23:08 PM GMT

Prettybird

two alternators in series along with the batterys? Industrial electronics that concern power is not cheap for sure. Mabe a big invertor to 110vac and knock down to 24vde power supply. You would only need one battery. I got a 1200watt inverter for the van but it worls best around 600 watts and has a fast cutoff citcuit. Research RV invertors.

$WMc%

Thanks for the Reply

I really don't have room for two ALT.s and inverters would run the cost up.

I have thought of modifying this circuit that I have for 12volt alternators. I just thought someone would have a more modern Idea.



_Thanks Anyway______$WMc%_______

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The Truth is out there············································ BoogerWoods, FL. USA

Philldapill

You could always use a high-power Boost Converter circuit. There are chips out there that will take care of all the logic, but you would need some beefy external MOSFETS and a good size inductor to handle that sort of power.

icepuck

Do have any salvage yards for heavy equipment in your area? If so look for a cat DP50 with the 5.0L 6cyl Mitsubishi diesel, they used two 12 volt batts for a 24 volt system, which means it used a 24 volt alternator and just use that as is. It's small and you won't have to make any modifications.
-dan

kwinn

$WMc%, you should be able to get 24V out of the alternator by increasing the current in the field coil. I had as much as 33V out of one a few years back with no problems. The only concern may be the voltage rating of the built in rectifier diodes. We wanted AC out so did not use them, and I have no idea what the voltage rating on them is nowadays.

If it is a problem you could always remove them and use external diodes.

PS - I believe trucks (tractor trailer) may use 24V alternators.

$WMc%

Thanks Again for the Replys

I called a couple of junk yards and a used 24 ALT. is expensive.

I over looked the possible voltage limits on the 12volt ALT. Rect.Diodes, Thanks for pointing this out.

A 24volt ALT. maybe the way to go even if it is expensive, I need a lot of power for this project.

24volt ALT. seem to be pretty tough and most I've looked up have a 100% duty cycle.


_____Thanks Again________$WMc%________

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The Truth is out there············································ BoogerWoods, FL. USA

Post Edited ($WMc%) : 7/19/2009 11:24:57 PM GMT

Prettybird

Check out old machinery electrical parts. Shipping may kill you but old electronics are now considered junk. A microprocessor is just a brain. The hi power electronics eat power. I have been in the machine tool industry most my life. So even if the stamp can control you need higher power interface for the control. Mabe it can regulate the car motor speed with a servo on the carberator and monitor current but what else can it do? Can't do much with 25MA. Even with my inverter in tha van ratted at 1200 watts will run down a battery in 30 min. or less. Have to use 4 awg short wire from the battery. Do the math. 10 amps at 120vac is about 100 amps on 12V. Or 50 amps on 24V in your case. I thought I could run a small microwave ratted at 750 watts but they don't tell you the start up watts. The inverter kicked out every time. Google solar power battery for the house stuff. You may learn more about power requirements. Just trying to get you in the right direction.

Prettybird

Forgot to mention. RV batterys are designed for running lower loads longer. Car batterys may not last as long.

$WMc%

Prettybird

Thanks for the Idea. I remember seeing some 24volt ALT.s, They were military surplus, and they were cheap.Now if I can remember where I saw them!

The two 880cca/ahr Battery's I have are DEEP CYCLE. their not just regular car battery's

I thought of the inverter as well but My experiences with them follow Yours.

Thanks for the Reply, I'm getting closer and closer to My goal.


___Thanks Again_____$WMc%_____

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The Truth is out there············································ BoogerWoods, FL. USA

Post Edited ($WMc%) : 7/19/2009 11:27:45 PM GMT

Prettybird

No problem. Good idea. Alot of military like industrial is based on 24VDC for transmission and noise reasons. Lots of surplus. All your PLC stuff is 24vdc or 110vac I/O. Most comercial people think 12V or 110vac. You can get things at almost give away prices if you can design around them.

Post Edited (Prettybird) : 7/20/2009 12:25:30 AM GMT