Discussion Board

Syndicate content
Live information from Fieldlines.com: The Otherpower discussion board
Updated: 59 min 20 sec ago

Re: 48V alternator (ICE driven)

Sat, 12/31/2016 - 01:46
It is this one again

http://www.anotherpower.com/board/index.php/topic,781.0.html

It ran for many months for 24/7 while the drought was on driving water pumps day and night... after many months... the drought stopped. It was left in the paddock beside ...

Re: 48V alternator (ICE driven)

Sat, 12/31/2016 - 01:11
Three Kw at 48v is around 60 amps.
If you are going to rewind it for 60 Amps, you will need your Superman suit, or if you are Popeye, lots of spinach.
Its not like a car alternator where there are three windings.
A 60 Amp rms single winding is pretty s...

Re: 48V alternator (ICE driven)

Sat, 12/31/2016 - 00:41
I am right now pondering my next move. I have a 48v unit to do, and so have built the car alt version as above.....

But...... I just got hold of a dead 3kw 240v AVR style 240v generator.... dead alternator, but good motor ( burnt windings )

I think I m...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 23:45
Excellent alternator writeup oZ.

There are many ways to skin a cat. 
If you are the average Joe with an old alternator, and a small serviceable gasoline engine, the way you did it is definitely the most logical and best way to go about it.

But someone...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 21:59
George....
Take it from me. I have written articles on conversion of alternators on this and other sites... I think on  this site it was "playing with alternators" where the theory and practice with lots of pics is covered in depth... down to regulato...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 19:37
Yes sure I have.
O/k choose any one specific point that I have made, that you consider to be totally and absolutely dead wrong, and let's discuss that in depth.

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 19:33
Quote from: Warpspeed on December 30, 2016, 12:53:25 PMWhat do you do for a iiving George ?

I am a retired power electronics design engineer.

I don't know what you did specifically but I can guarantee it was not worki...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 14:31
Quote from: plasmahunt3r on Today at 10:57:14 AMForget about the Field coil.  If I were doing this, I would get a 48v Permanent Magnet Alternator.  They don't need a field coil and they are designed to run at low RPM...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 13:53
Quote from: george65 on Today at 08:22:40 AM
Pretty sure High RPM is NOT a factor. The power applied to the rotor controls the output more than speed. Once the alt is up to it's design speed range, it's the rotor curr...

Re: Solid State Relays, Uses, and Trigger Circuits

Fri, 12/30/2016 - 12:22
In my application I used zero-crossing SSRs, and was aiming to drop out a small number of half cycles to reduce power delivery to a (dumb) appliance such as a kettle.  I didn't synchronise the AVR/Arduino to mains but it still worked well enough as I w...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 11:57
Forget about the Field coil.  If I were doing this, I would get a 48v Permanent Magnet Alternator.  They don't need a field coil and they are designed to run at low RPM.  Low RPM means less fuel to operate.  Plus no brushes to wear out.  Overall saving...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 11:24
There are adjustable buck converters that will work up to 60V to supply the lower field voltage.  It is also very easy to fool these buck converters, using only one extra wire to the board, that can adjust the field using a TL/LM431 like every line ope...

Re: Solid State Relays, Uses, and Trigger Circuits

Fri, 12/30/2016 - 11:17
Depends on what you call PWM. A triac or SCr will trigger and stay on.  In the case of random firing SCR the standard PWM of 480 Hz really can not be used.  When ever two frequencies are mixed you will get sum and difference of the two frequencies.  Tr...

Re: Solid State Relays, Uses, and Trigger Circuits

Fri, 12/30/2016 - 09:42
George, the Arduino should run the SSR just fine. It sounds like you are switching AC with them and plan to PWM it so you should know that many SSR's are what they call "zero crossing" which means that when you turn them off or on they wait until the n...

Re: Solid State Relays, Uses, and Trigger Circuits

Fri, 12/30/2016 - 09:30
Hope this is not too off topic but can anyone tell me if the arduino boards can direct Drive one of the square white SSR's that come in 10 - 40?A Range?
the DC Side is 3-32V but not sure what amps are needed to switch the the high side of 24-380V

Want...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 09:22

Pretty sure High RPM is NOT a factor. The power applied to the rotor controls the output more than speed. Once the alt is up to it's design speed range, it's the rotor current that controls the output not spinning the bejesus out the thing.

I also be...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 02:39
This application is being driven by an internal combustion engine, so that its not a problem.
It would not be too difficult to automatically switch off field excitation at zero rpm,  through design of the regulator.
PWM drive of the field winding is a...

Re: 48V alternator (ICE driven)

Fri, 12/30/2016 - 01:59
But what happens when the wind stops?  You are still dumping current into the field.  I don't remember them being that good at self excitation.  Anyway, the field coil is just a big inductor and you could easily PWM it even with just a simple TL431 cir...

Re: 48V alternator (ICE driven)

Thu, 12/29/2016 - 22:11
Yup, that is certainly one way to do it.

Pretty sure field current will be in the three to four amp range for most alternators, but it does vary with size and brand.
At 36 volts that is around 100 to 150 watts dissipation.
Both the heat sink and trans...