easy access to changing voltage regulator components

[shmuelbrody]

i need to change the voltage of a 12v car alternator to 36 volts
i need to know what make and model of alternator is the easiest to change and to get into
it should also be fairly low cost as i need it for a component in a generator that i want to manufacture
the model should be easy to get into
to chanege the diode
and to reinstall
it shluld also be a standard model so that i can reorder as needed
i have spent 1 solid month on this project and am totally exhausted in my search
i would greatly appreciate any help
thanks shmuel
israel

[MagicRat]

I may be wrong here, but I think the maximum output from a 12 vol alternator is about 15 or 16 volts, when the voltage regulator is disconnected. I think any further boost in voltage would require more modification than is worthwhile.

I googled 36 volt alternator and got several sites selling new 36 volt DC-output alternators.

If you must use 12 volt alternator, try a 12 volt to 36 volt boost converter

[shmuelbrody]

thanks for the reply
i appreciate your comment but
you are not on key

i need to know what model and make of
alternator is easily opened and available to
get to the regulator comonents
not a sealed regulator

i dont need to know hhow to increase the voltage
what you do is open the alternator
get to the reg ulator and take out the diode thet specifys
whaich voltage the alternater will make and replace it
with a diode that will increase the voltage

an alternator with out a regulator will go up to 100 volt if you increase the speed of the rotation ,,,,,,, nothing more

if y ou go that high you have to change the components so that they can handle the highe voltage
but to go to 36v nothing is necessary but to change the one diode
unsolder it and soder in a new one

thanks again

[shmuelbrody]

i am sorry that i did not include
the informationa about buying 36v alternators

yes on line it is possible them
from china

minimum order is 100 pieces at $50 each
and$400 in shipping

Thats 5400 dollars for one altenator
they wont do less

it is absolutely impossible to get one

as for a volatage increaser
that would be about $200
for each unit and would put me out of
a target price for sale of my product

all i need is to change a 25 cent diode to make this work

thanks
shmuel

[shorod]

If it's truly a diode that needs to be changed, it would have to be a zener diode. There certainly would be a zener diode within a standard regulator assembly, but not as part of the diode bridge.

If you know there's a regulator assembly that makes this so simple, can you cross reference which alternator uses that regulator assembly to identify which you need to purchase?

I suspect most modern alternators will use a regulator assembly that is potted to withstand high shock and vibration requirements along with thermal. To find one that has discrete components easy to replace, you're probably looking at something from a few decades ago. And even then, if the regulator has ever been replaced, there's a chance it's been replaced with something using more modern technology.

How much current do you need this device to provide? How much filtering does the 36V need to have, and how well regulated does it need to be? Have you considered buying an old Ford alternator that used the external voltage regulator, then building your own regulator? If you're not worried about short circuit protection you can build a high current regulator using a simple 3-terminal regulator (such as the LM317), a pass transistor, and a few additional passive components.

-Rod

[shmuelbrody]

thanks rod

here is the schematic of the regulator to build and that is adjustable
it has several options

easy to do but i dont have a lot of experience with building
and when i do it usually dont work

i guess i dont know to debug

an old ford generator
are they available new
i live in israel and cant go to a junk yard
also i may want to build a lot of these
is there a model that i can
order and have shipped here

what kind of idea do you have for a build
most of the ones that ive seen in the last
several months look like this

would like to continue this conver
it seems to be going somewhere
thanks
shmuel

[shmuelbrody]

it would seem to me that any alternator that has a detach able internal regulator
the regulator could be taken out and this schematic could be connected to the
wires that went to the regulator
is that so rod?
shmuel

[shmuelbrody]

How much current do you need this device to provide?

about 60 amps

[COLOR="rgb(255, 140, 0)"] How much filtering does the 36V need to have[/color],

it needs to be dc
if need be i can put a 5 farad cap on it to smooth the bumps to straight dc


[COLOR="rgb(255, 140, 0)"]
and how well regulated does it need to be? [/color]

36 volts straight on or 38
not higher and not much lower




Have you considered buying an old Ford alternator that used the external voltage regulator, then building your own regulator? If you're not worried about short circuit protection you can build a high current regulator using a simple 3-terminal regulator (such as the LM317), a pass transistor, and a few additional passive components.

id have to see a schematic

thanks rod
shmuel

[shorod]

Yep, those schematics all show changing out a zener diode on the base of the pass transistor to regulate the voltage. Those schematics are pretty much doing the same thing as an LM317 with pass transistor.

As for finding new alternators with external regulators could be a trick where you live. I don't have a particular part number in mind. I just remember helping Dad with some Ford cars that were older than me and had an external finned box mounted on the fender liner. Dad said it was the external voltage regulator. You might check what was in a 1968 Mustang or 1970 Torino, then see if either of those are available where you live.

If you are storing the charge from the 36V alternator in 3 series car batteries, then the batteries will probably provide enough filtering that you would not need the capacitor.

-Rod

[shmuelbrody]

thanks again rod
i dont need to buy here in israel
i can buy in the states and ship to israel uspo
if you could give me a modell no that you know i could get inside access to
that would be nice
perhaps i could contact manufacturers
like mopar to get specific info
you did not answer my question about
taking a modern alternator and pulling out the regulator
if it will unplug and adding an external regulator
do you have a scxhematic for the regulator that y ou mentioned
thanks again
shmuel

[shorod]

I don't know of a specific model that has the external regulator, but I did mention a couple of vehicles to check. Also, when I was working with those alternators and regulators I was still in grade school and never took the regulator apart or tried to figure out what the various wires went to in the alternator, so I cannot say for sure if you would be able to just drop in an external regulator. I do think you want to stay away from a modern alternator since some have a lot more computer control functionality to limit voltage and current output based on vehicle load, etc. I don't know how that added functionality impacts the field coil and stator winding connections.

If you pull up the datasheet for an LM317 voltage regulator there are example diagrams in the datasheets for high current regulators using a pass transistor. The LM317 is only designed for up to 40V input and 37V regulated output, so it would be near the top of the range you are interested in. I don't typically deal with voltages that high, so there may be other regulators similar to the 317 that would work better for you application. Although the regulator schematics you included above don't look very complicated. The third one you listed even seems to be for exactly what you are trying to do. Did they mention a model of alternator/regulator that this diagram came from?

-Rod

[MagicRat]

Virtually all North American Fords used external regulators in their alternators, from the introduction of the alternator (1964 model year) to the mid-1980's or so.

I suggest get an alternator from a late 1970's Lincoln. They had high capacity, wrapped in a durable, large-frame style, and a simple double V-belt pulley (not the less-adaptable Micro-V style). The luxury nature of the cars meant lots of electrical accessories and lots of draw, hence the substantial output.

Originally Posted by shmuelbrody

i am sorry that i did not include
the informationa about buying 36v alternators

yes on line it is possible them
from china

minimum order is 100 pieces at $50 each
and$400 in shipping

Thats 5400 dollars for one altenator
they wont do less
l

Whoa! I didn't suggest you should buy a truckload of Chinese alternators. I suggested to do some research. Try going to the second link that pops up.
Look here:
http://www.americanpowerinc.com/36%2...Alternator.htm
These folks also make 36 volt alternators on a custom -build basis: http://store.alternatorparts.com/alternators.aspx

You should take these links and their products seriously. Your idea to use an automotive alternator has some deficiencies. Auto alternators are not designed to cope with long periods of high draw. They will overheat and fail, or your generator will be limited in usable output. Trust me on this, charging up 3 typical storage batteries at once will cook your alternator. It makes more sense to get a device designed for 36 volt applications and heavy loads. This means industrial or heavy truck alternator.

You may find their products are affordable. You are already considering shipping a new or rebuilt alternator from the US, because used ones are not available to you. This option has some expense. So you may find a proper alternator for this proper application is within your budget.

Finally, you can wire three alternators using three batteries and isolators. It may not suit your application, but for the sake of the conversation, I'm throwing it in there.

For 36 volts (three batteries) the alternators would need to be wired like this:
1.) Alternator #1 would have the ground connected to the frame of the generator. The 12 volt output from it would go to the positive terminal of the first battery and this would be the battery to run the rest of the vehicle off of for 12 volts.
2.) Alternator #2 would have it's isolated ground connected to the positive terminal of the first battery or the negative terminal of the second battery. Then the 12 volt output from it would be connected to the positive terminal of the second battery. From the positive terminal of this battery to chassis ground would be 24 volts.
3.) Alternator #3 would have it's isolated ground connected to the positive terminal of the second battery or the negative terminal of the third battery. Then the 12 volt output from it would be connected to the positive terminal of the third battery. From the positive terminal of this battery to frame ground would be 36 volts.