Transforming 12 vdc to 24 vdc

[veggie]

Is anyone aware of a voltage converter/transformer which can take 12 volts and bump it up to 24 volts (at 1/2 the amperage).

I have a Leece 12V, 140 amp alternator and once I graduate from a 12 volt to a 24 system, it would be nice continue to use this quality unit.

Current output: 14 vdc @ 140 amps (max) = 1960 watts

Desired future output: 28 vdc @ 70 amps = 1960 watts (less conversion losses of say 10%) = 1764 watts

Is there a single devise which can do this?

veggie

[injin man]

No, there's really no silver bullet. Bob has a White Paper
in that section on converting the 110-555 jho types to put
out 24V.

HTH

IM

[Ronmar]

I would also suggest shifting the alternator to 24V.  The only real difference between a 12V and a 24V alternator is the regulator.  When it comes right down to it, the main difference between a basic 12V and 24V regulator is probably the zener diode used along with the voltage divider network to determine the output voltage regulation.

They make 12 to 24 switching power supplies, but you will take a further efficiency hit for that.

[BioHazard]

I agree....not only would that be inefficient, but, it would cost a lot of money if you can find one. Probably more than the alternator.

[veggie]

I would also suggest shifting the alternator to 24V.  The only real difference between a 12V and a 24V alternator is the regulator.  When it comes right down to it, the main difference between a basic 12V and 24V regulator is probably the zener diode used along with the voltage divider network to determine the output voltage regulation.

They make 12 to 24 switching power supplies, but you will take a further efficiency hit for that.

Thanks Ronmar,

I was not aware that these units could be converted to 24 vdc by changing a few internal components.
I will contact the local Leece dealer and get the parts.

veggie

[XYZER]

I was not aware that these units could be converted to 24 vdc by changing a few internal components.
I will contact the local Leece dealer and get the parts.
veggie

veggie
Let us know what you find out.....I am walking the same path....

[injin man]

I would also suggest shifting the alternator to 24V.  The only real difference between a 12V and a 24V alternator is the regulator.  When it comes right down to it, the main difference between a basic 12V and 24V regulator is probably the zener diode used along with the voltage divider network to determine the output voltage regulation.

They make 12 to 24 switching power supplies, but you will take a further efficiency hit for that.

Thanks Ronmar,

I was not aware that these units could be converted to 24 vdc by changing a few internal components.
I will contact the local Leece dealer and get the parts.

I don't think they offer a kit for this. You should read Bob's White Paper first.

veggie

[DanG]

Pardon the logic - but how about passing on your known good unit at a small discount to some unsuspect... err, hobbyist and shopping hard for the next unit? It's the many-headed monster of 12V-24V-48V systems upgrades benefiting only the retailers if we can't subsidize others with our mistakes... err, system changes.

[squarebob]

Maybe I can help subsidize from my "System Change",
I have a Leece 8SA3065PC 24v 75a Large Frame alternator available for someone in need. There is one on fleabay for 185.00. A member here can have mine for $100 plus shipping. It is tested but unused. It requires an external regulator. I tested the unit with a Balmar reg and it works just fine.  
Veggie gets first dibs since this is his post!!!
PM me if interested.


Bob

[veggie]

Hey Squarebob,

Thanks for the offer. Unfortunately I think the freight to Canada would kill the deal.
Otherwise I would jump at it.
Price is right 

thanks again,
veggie

[injin man]

I've been Bolean this weekend and came across this tidbit
on Alternators. Lots of useful stuff here, if you're old salt
skip the 101. There is a reference to controlling the input
to the field to control the output, I assume this is for fine tuning
the output.

http://altenciruits.wordpress.com/2011/03/26/altenatorsdynamos-and-generators/

[LincTex]

Let us know what you find out.....I am walking the same path....

Me too! I have one (12 volt) given to me recently! 
I need to know how to make it run for a 24 volt system!

[Ronmar]

Well if you read thru Bobs White paper on alternator efficiency, the quick and dirty way would appear to connect the alternator output across your 24V string, but connect it's regulator sample input across 12V of the 24V bank.  The regulator will adjust the output which is fed across the 24V bank, to reach it's desired 12V level as measured in the middle of the bank.  IE: It will drive the output to 24V to get 12V in the middle where it is sampling.  You do need to provide a 12V source to power the alternator field though...