48v alternator

[stinga]

G'day all,

So following from https://diysolarforum.com/threads/c...ery-from-an-alternator-24v-in-my-case.110793/

I was chatting to a mate about this issue and he said, I have a 48v alternator I could have.
It brand new and he knows nothing about it. If I can't get it working he would weigh it in for scrap.

Trawling the net I find these things on aliexpress but there are no details.
I don't know what voltage it needs to produce power.

Anyone got any advice?

 

[seneysolar]

That will need a voltage regulator. B+ goes to battery and the 2 smaller terminals are the brushes. One gets field current from regulator and the other typically goes to ground.

 

[stinga]

@seneysolar Thanks..

There is also a B-, my photo chopped it off.

What I am unsure about now is the voltage that needs to provided to make it work.
I am learning but my knowledge about these things is low currently.

I just had a quick look at the Arco Zeus specs and can see it needs to be powered by 12v. I have 48v house voltage and 24v chassis voltage... hmmm...
(shame its not multi voltage, then I could just power it with the 48v house voltage)

Maybe the zeus does dark magic and it just works if you connect it all up?
wakespeed seems to be mutil voltage...

(When I say 46v I also mean 56v lifepo4 voltage)

How do they work?
Ignoring the regulator system voltage to make it work...

1. The regulator knows the battery voltage
2. The regulator is programmed with the necessary setting to charge a 48v lifepo4 battery

Thus it just alters the field(?) voltage until it gets the correct output voltage? So it `just` works as advertised?

 

[stinga]

More....
I removed the carbon brush pack and it is a regulator.
I am getting ~5 ohms across the slip rings, so this leads me to believe it requires 12v to excite the alt.

I then removed the silicone potting from the reg and got...

There is a potted capacitor the other side, maybe connected to the W post...

I can remove the electronics and get unfettered access to the carbon brush connectors.

Given all the above I think I can use an external regulator to control this thing.

 

[stinga]

I have done more investigation


I have label the tags in the regulator, not easy to see in red :-(

1 Connects to the top brush
2 Connects to the unmarked post and the bottom brush
3 Connects to a capacitor (on the other side) and then connect to B-
4 Connects to the W Post and is not connected to anything else, so does nothing
5 Connects to B+ and the capacitor

I believe I can rip all that out and do the following:
Disconnect the B- and B+ posts, but do I need to leave the capacitor in place between b- and b+?
The unmarked post and the W post I can reuse to connect to the brushes by removing the exiting connection and making the posts connect to the brushes

This should mean I can use an external regulator connected appropriately.
Looking at the wakespeed manual, basically I need 4 connections which the above would give me.

One question I have is how do I know which is +ve on the brushes...
I looks like 2 is connected to the cathode of the rectifier diode (GS5M) which is -ve and that is connected to the bottom brush, therefore bottom is -ve and +ve is top, so the current reg. is controlling the alt via +ve (?)

 

[ConnerLabs]

I have done more investigation
View attachment 348345
One question I have is how do I know which is +ve on the brushes...
I looks like 2 is connected to the cathode of the rectifier diode (GS5M) which is -ve and that is connected to the bottom brush, therefore bottom is -ve and +ve is top, so the current reg. is controlling the alt via +ve (?)

Unless I'm completely mistaken, it shouldn't matter, you can connect the field power supply to the brushes with either polarity and it works the same.

 

[stinga]

Unless I'm completely mistaken, it shouldn't matter, you can connect the field power supply to the brushes with either polarity and it works the same.

You know what, I believe you are correct... the alternator is AC and the diodes rectify it to DC... so it will not matter...
I am being thick!

Thanks @ConnerLabs

 

[Rushguy]

Since you have an inverter, have you thought about adding a belt driven AC generator? You can get them for under 500 dollars and they can continuously produce between 3 and 10 kw. Your inverter would clean up the cycles and voltage. For the cost of a wake speed regulator, you could buy an entire continuous duty generator dedicated to just charging your battery bank.

 

[stinga]

Don't they to spin at a specific speed to get the Hz correct?

 

[Rushguy]

Don't they to spin at a specific speed to get the Hz correct?

Yes the cycles could be wrong, and I wouldn’t use that ac to run super sensitive equipment, 99 percent of things would be ok with the wrong cycles. Most inverters don’t care, I would look at your inverter and see if it specifies the cycles.

 

[stinga]

Victron multiplus II

 

[seneysolar]

Yes the cycles could be wrong, and I wouldn’t use that ac to run super sensitive equipment, 99 percent of things would be ok with the wrong cycles. Most inverters don’t care, I would look at your inverter and see if it specifies the cycles.

Huh? Most inverters DO care about hertz. Its the primary reason people have trouble getting a generator to work with their inverter. +/-5 hz can be a deal breaker for 98% of the inverters out there.

Voltage window is much more forgiving. +/- 20v is usually fine with LF inverters.

 

[Daddy Tanuki]

yep i can say for a fact that many of the slightly older 10-20 year old LF US offerings did not like frequency being off. zantrex comes to mind. i had one and it would not run off of a japanese inverter generator unless i set the cycles to 60. then to make it worse the japan standard 100 volts was just enough to make it drop out about every other minute... i gave up on it and went with a magnum which did not care about the the voltage as long as it was 60 htz.

 

[ConnerLabs]

The comparison would be a belt-driven AC generator running something like a Chargeverter.

 

[HarryN]

Don't they to spin at a specific speed to get the Hz correct?

Depends.

If it is a generator designed for a specific frequency use, then it has to be a match to the rpm of the vehicle.

If it is an aircraft generator, then those often have a transmission to run them at a constant frequency / rpm.

If it is an alternator like a car or truck uses, then they might even be a 12 phase variable frequency generator that runs through diodes to made the 12, 24 or 48 volt DC.

The output is controlled using the field current. On a modern car, the engine ECU does this. On higher end ones, they have a separate field current controller.

Wikipedia has an article on them.

Alternator - Wikipedia

en.wikipedia.org

 

[doing it different]

An alternator has way higher frequency then 60 hz it's not even close. From. My understanding aircraft is even higher