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Forum Index : PCB Manufacturing : Need cad file for 48v regulator

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BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 960
Posted: 10:51pm 02 Aug 2020
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I was hoping somone would want to design
a external 48 volt voltage regulator for a alternator

I am would pay them for it

I would need a cad file so I can get pcbs
made

Anyone interested please private message
me with price

I am not even sure I could afford it but would appreciate any info on prices and how to make it happen

Thanks for your time
be warned i am good parrot but Dumber than a box of rocks
 
bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2476
Posted: 12:11pm 03 Aug 2020
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Hi Ben,

What exactly are your specs?

Ie.

Physical size you are looking at
Current draw/load
Input power specs ie. 240Vac , 60VDc, 24v dc?

I gather the alternator supplies the source power..

Do you have a schematic of a working one?

It might be out of my skill set if high current as you would need some serious pcb copper..

Any way over to you.

Regards,

Mick
Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<
 
BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 960
Posted: 01:53pm 03 Aug 2020
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It needs to work like a normal car truck van alternator

It controls the field coils with up to 4 amps to regulate the output of the alternator

With the voltage being 48 volts instead of 12 may only need one amp for full out put

Thank you for your time!
be warned i am good parrot but Dumber than a box of rocks
 
bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2476
Posted: 05:37am 06 Aug 2020
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Hi Ben,

If you have some circuit schematic I think I should be able to knock up a design for a PCB for you (Happy to it for free or for a couple of beers).

I think, at this stage I will abstain from designing the circuit itself as I know little about how alternators work.

Kind Regards

Mick
Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 4320
Posted: 07:15am 06 Aug 2020
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That is the problem Mick.

Ben still seems to think a 12v alternator with the right kind of regulator fitted to it can supply 48v output.  
He does not seem to realize, even though its already been explained to him, that a voltage regulator can only REDUCE the output voltage, not increase it.

He keeps asking repeatedly for someone to design something to do the impossible, it just goes on and on.
Edited 2020-08-06 17:26 by Warpspeed
Cheers,  Tony.
 
bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2476
Posted: 11:27am 06 Aug 2020
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Hi Tony, Ben,

If that is the case, that it is a 12v car alternator and you need 48v and  it is only 1amp

You could use a 150 w inverter and then generate your 48vdc from that..    a bit clunky but possible?

Ben, is this for use in a car or similar? Or on some other application?

Regards,

Mick
Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<
 
Chopperp

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Joined: 03/01/2018
Location: Australia
Posts: 891
Posted: 10:59pm 06 Aug 2020
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Hi,

I don't want to ruffle anyone's feathers but a 12V alternator WILL produce more than the 13.8V or whatever the manufacturers decide is good for our batteries.

I have a 12V alternator with a home built external regulator connected to an engine producing 42V for a 36V system.

The field still has to run from a 12V supply to limit the current which the regulator controls.

(I did mention this system in another post many moons ago when this subject previously came up.)

My in initial setup had a fairly high pulley ratio & I got the rated current out of it. I've since relocated the alternator & had to lower the pulley ratio with a subsequent reduction in the 42V O/P current.

The only thing I am sort of worried about is the voltage ratings of the main diodes if the voltage is taken too high. There maybe other factors I haven't considered or really worried about.

With my initial setup, the load was only intermittently high, so it was never tested for continuous operation.

Now what did I do with the circuit?

Brian
ChopperP
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 4320
Posted: 12:34am 07 Aug 2020
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  Chopperp said  Hi,

I don't want to ruffle anyone's feathers but a 12V alternator WILL produce more than the 13.8V or whatever the manufacturers decide is good for our batteries.
Brian

Yes, but to charge a 48 volt battery, it needs to be turned at about roughly four times the normal rpm, and that is going to be a real problem in a road vehicle.
Cheers,  Tony.
 
Chopperp

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Joined: 03/01/2018
Location: Australia
Posts: 891
Posted: 02:32am 07 Aug 2020
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I agree re RPM. He may be able to use a bigger drive pulley and/or run the engine faster.

There certainly has to be a better solution all the same.

RE Ben's 1 amp. I think he was referring to the field current which was not a correct assumption on his part.

Brian
ChopperP
 
CaptainBoing

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Joined: 07/09/2016
Location: United Kingdom
Posts: 1686
Posted: 09:47am 21 Jun 2021
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Hello Ben. Only just read this old post - if it is still a problem for you... might be a wild out-field shot, but had you looked at something like this:
DC-DC converter 10-60Vin 12-90Vout ?

Claims to be 30A/1500W but I can't vouch for it in any way and bearing in mind it will be made from purest chinesium, but might get you nearer to what you are after. VOut likely to be noisy as hell due to the switching of that huge inductance, especially as current draw goes up so bear that in mind.

The question pops in my head, is the output regulated? - i.e. does VOut change as VIn changes? If so, that might be a problem on a truck due to fluctuations in the charging state of the vehicle battery i.e from nominal 12V to somewhere around 14V.

Worth a punt for $40 (can be found cheaper if you hunt around) - at worst if it is no good you can make a really nice hgh-voltage bench supply from it.

all I got.

h
.
Edited 2021-06-21 20:57 by CaptainBoing
 
Godoh
Regular Member

Joined: 26/09/2020
Location: Australia
Posts: 95
Posted: 09:02am 22 Jun 2021
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Most car alternators have the ability to generate up to around 120 volts if spun fast enough. There was a company once that made an add on box that had a voltage doubler in it, that allowed universal power tools to be run from the car alternator.
They also had a switch that put full 12 volts onto the fields and allowed light welding to be done from the alternator. (the product was called AutoArc from memory)
So getting 48 volts to charge a battery is possible but one would have to be careful with how much current you put out. The alternator could get pretty hot.
I use an alternator to charge batteries on my solar system on the very rare occasions that the sun doesn't shine enough. My setup is crude. It just has a rheostat to adjust the field current. I start the petrol motor, wind the field up and check the current with a clamp meter. I used to set it to 50 amps ( it is an 80 amp alternator) and leave it, whilst checking the batteries regularly.
Yep crude but worked well.
I have not tried it since going over to 24 volts, as I haven't had the need.
Regulating an alternator output can be counter productive as the regulator will keep winding the current down when the battery surface voltage rises. You end up using lots of fuel and making lots of noise without doing much charging.
I am a bit of a keep it as simple as possible type, so manual setting and regular checking works for me.
Pete
 
BenandAmber
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Joined: 16/02/2019
Location: United States
Posts: 960
Posted: 07:36am 23 Jun 2021
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I was thinking of a gas or propane back up battery bank charger

I still would like to make one
I have 3 or 4 car alternators saved back and a few small gas engines

I also have a small pile of pulleys of different sizes

I am like the wind from one thing to the other be close to revisiting this project

It could be just a bulk charger that has a constant charge amperage

And be made to kick off  at a settable voltage

If the it would be better to use 12 volts for the magnetics that would not be bad

The same 12"to 15"  volts could charge the starting battery
Edited 2021-06-23 17:42 by BenandAmber
be warned i am good parrot but Dumber than a box of rocks
 
Godoh
Regular Member

Joined: 26/09/2020
Location: Australia
Posts: 95
Posted: 02:58am 25 Jun 2021
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The magnetics can be powered from the 48 volt supply. Usually car alternators rotors pull around 3.5 amps at full output.
So you need a variable resistor that can drop around 40 volts at 3.5 amps.
I use a 50 watt rheostat on my charger, you may need something a bit bigger. You could use a 100 watt rheostat around 30 ohms would do, then you could put a car headlight bulb in series with it to limit the current a bit more.
The best way for you is to get a 24 volt truck alternator, that way it will be capable of more current at your required 48 volts, and the fields will not need such a large drop in voltage to set the current
Pete
Edited 2021-06-25 15:05 by Godoh
 
andrewacain
Newbie

Joined: 17/08/2021
Location: Canada
Posts: 2
Posted: 12:01pm 24 Aug 2021
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You could power four 12V batteries in series with four 12V alternators, but each one must be insulated from the ground and from the others. Do you have the schematic circuit design? It would be helpful for us to understand with a schematic. If you don't have a schematic you should design one or you should ask some electronics manufacturing  team for helping you design one. Make the connections according to the schematic layout.
Thank You.
 
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