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Re: e-Buggy: Alternator Conversion

Posted: Sat Apr 17, 2010 12:13 am
by zenon
Hi John500

Hehe :D that's the outcome when someone like me write posts late at night :lol:
Ya that is my 2nd tadpole build with a rear suspension, downhill disk brakes and still on the go.

Great tips on hunting giant alternators. For now I can only imagine the amount of power I can push it to with lithium batteries at 48v to 72 volts or maybe at 100V. The stator wires in some alternator that I've seen from the past were thick gauges equal to serious power output abuse since it will be controlled by AC 3 phase and not DC as it was designed to do. Structure wise, this units I'm almost sure can reach as high as 10kilo watts or higher burst power.
Maybe need to open the armature and rewind it with thicker wire gauge for serious torque.

I also like the fact that the rotor magnetic flux can be controlled by voltage , it will act like a variable electronic transmission plus the stator can be easily setup with wye and delta by a flick of a switch for turbo mode which is very awesome. :twisted:

If you are in the Vancouver area next year VEVA REV show you might just see a Nacho Libre style tadpole powered with lithium packs and some monster alternator motor on display. :mrgreen:

Cheer's

Zenon

Re: e-Buggy: Alternator Conversion

Posted: Sat Apr 17, 2010 11:30 am
by John500
We used automotive alternators for years to put out 117V to run small power tools. They will produce 1Kw but they will get hot in continuous use. With additional cooling, who knows what they will live with?
I'm in Vancouver for a few days next week and will look around the e-bike shops for some parts.

Re: e-Buggy: Alternator Conversion

Posted: Sun Apr 18, 2010 7:28 am
by magnusvr
Hi widodo,

Here's that guy from Sweden again, from the Hobbyking Forums. :)

I haven't come very far since last time. :)

We opened one alternator but it was broken (might be that we "broken" it during diassembly)... Last week I got a new 70 Amp one from a -89 Golf Gti. I think it's Bosch.
I understand everything about powering it up, I have read alot online. Everything except the 3 wires from the spools. What do I do with them? Do i just cut them off and connect to the brushlessESC? Is it that simple? Or do I re-arrange them somehow? I know you mentioned Delta/star-pattern, I just can't understand how to do that in reality. There are only 3 wires, how can I rearrange that? Do I include the diodes? I feel :oops: .

Image

In the picture you see the three wires, and also some diodes. What do I do now? :)
My wire cutter and soldering iron is ready to work!

I have a 30Amp brushless ESC for testing, will order a 150A from Hobbyking when I get the altmotor working. This will be 12V powered.
For the magnet I also have a brushed RC-car ESC of good quality, suitable for 11 turn motors. I guess this will be 7,2 volt powered. Or lower if you recommend it.

Thanks for any help!

/Magnus

Re: e-Buggy: Alternator Conversion

Posted: Sun Apr 18, 2010 10:48 am
by zenon
John500 wrote:We used automotive alternators for years to put out 117V to run small power tools. They will produce 1Kw but they will get hot in continuous use. With additional cooling, who knows what they will live with?
I'm in Vancouver for a few days next week and will look around the e-bike shops for some parts.


Hi John500

That is interesting info, it get hot because not only its beside a running engine but maybe because the there is an internal impedance mismatch between the source and load. In motor conversion we are only dealing with the stator impedance plus its pulsed so i believe it can go way higher in power before it melts. We shall see :D

P.S. PM me when your in Vancouver area, maybe we can hook up and show you my tadpole setup.

Cheer's

Zenon

Re: e-Buggy: Alternator Conversion

Posted: Sun Apr 18, 2010 3:11 pm
by dajsinjo
magnusvr wrote:I understand everything about powering it up, I have read alot online. Everything except the 3 wires from the spools. What do I do with them? Do i just cut them off and connect to the brushlessESC? Is it that simple? Or do I re-arrange them somehow? I know you mentioned Delta/star-pattern, I just can't understand how to do that in reality. There are only 3 wires, how can I rearrange that? Do I include the diodes? I feel :oops: .


Yes, just cut the wires and connect to brushless(and sensorless) esc.
Other 3 ends are solderd together somewhere in the spool, which is a star, don't touch that, you don't need to rearrange it !
You don't need diodes any more,
unless you want to arrange some strange regenerative braking where motor becomes alternator again

Re: e-Buggy: Alternator Conversion

Posted: Mon Apr 19, 2010 7:51 pm
by dajsinjo
Conversion finished!
Controller should be flying in soon

Re: e-Buggy: Alternator Conversion

Posted: Tue Apr 20, 2010 12:34 am
by zenon
dajsinjo wrote:Conversion finished!
Controller should be flying in soon


Sweet :D Whats the weight?
What kind of controller are you using?
At what voltage?

Zenon

Re: e-Buggy: Alternator Conversion

Posted: Tue Apr 20, 2010 7:27 am
by dajsinjo
zenon wrote:
dajsinjo wrote:Conversion finished!
Controller should be flying in soon


Sweet :D Whats the weight?
What kind of controller are you using?
At what voltage?

Zenon


I don't know abou the weight, maybe 3 kg
for the rotor(armature) I use rheostat 0-10 Ohm + 4.5 Ohm armature resistance
For stator I orderd this controller:
http://cgi.ebay.com/200A-Brushless-Moto ... 23063c1259
Maybe not the best but the cheapest

To try it out I powered armature with 12V,
connected 3 phase with each other(short circuit)
and rotate it with my hand,
than change resistance with rheostat and observe how the torque changes

It is pleasure to see things work as they should!

Re: e-Buggy: Alternator Conversion

Posted: Tue Apr 20, 2010 7:39 am
by dajsinjo
My brother crashed his Honda Prelude,
so I got my hands on his alternator :twisted: and took it apart

I am a bit confused about 4 wires comming out from stator, the bridge lookes like it has 8 diodes.

Is it possible that it is 4-phase alternator?

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 21, 2010 5:42 am
by Fligh High
Dajsinjo , that's an interesting alternator that you have there , those connections coming out of the stator are absolute PERFECT and make it very easy to connect cables to !! The bottom tap/connection looks like it is not the same distance as the others maybe that is a center connection of the windings ? (star-configuration) Please measure the resistance between each connection and let us know ...
Maybe if you scratch the plastic/glue/isolation stuff away from the electric channel between the connections/regulator you can see how it is connected .

If you have any alternators running post some vids please ! always fun to see them.

Wow looks like a lot of people from all over the world are converting alternators this year :D ALTER-MOTOR CONVERTERS UNITE !! 8)

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 21, 2010 6:23 am
by dajsinjo
Fligh High wrote:Dajsinjo , that's an interesting alternator that you have there , those connections coming out of the stator are absolute PERFECT and make it very easy to connect cables to !! The bottom tap/connection looks like it is not the same distance as the others maybe that is a center connection of the windings ? (star-configuration) Please measure the resistance between each connection and let us know ...

that is exactly what friend of mine suggested!

I have allready masured the resistance and it is the same in ALL combinations!

It doesnt say but it lookes like Bosh alternator, and yes, it is very easy to connect cabels.

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 21, 2010 6:47 am
by dajsinjo
Fligh High wrote:The bottom tap/connection looks like it is not the same distance as the others maybe that is a center connection of the windings ? (star-configuration) Please measure the resistance between each connection and let us know ...
Maybe if you scratch the plastic/glue/isolation stuff away from the electric channel between the connections/regulator you can see how it is connected .


YES YES YES !!!! you are RIGHT!!!
the one at 10 o'clock is a star connection !
I took the rubber off and saw 6 wires connected to it, others have 2 wires.
resistance is half between star and phase than between phases.

I am still waiting for the controller , than you will see them spinning!

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 21, 2010 6:47 am
by Fligh High
Weird ! I don't know much about alternator designs other than the usual , why would they do something like that ? But it probably does not matter for an alternator how many field-windings it has since it will always be DC after the diodes...

If indeed 4 windings , it would make a nice 4 pole big stepper-motor ! If my memory is good that is what they use for diy CNC machines and so.

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 21, 2010 6:50 am
by Fligh High
Ai Dajsinjo...you were quicker than me with posting....but good to see it is useable more for you with the normal 3 windings ! no problems there...
Could it be , because all the diodes were still connected , you could not measure differences between the winding-connections with an ohm-meter ? I think that's why maybe.
If possible when you have your controller could you try running it with the Star-formation ?

If some of the more experienced members in e-motor design happen to read this I've got a question :

How much do you actually give up in torque/power or what are the other differences if you would drive a motor in a STAR center-connected to ground instead of delta/wye ??
Could it be beneficial in the higher revs maybe or is it simply always worse ?

Because it is so easy to connect in that way....and if you make your own cave-men controller circuit for driving the fets no worries about shoot-through and such , very simple design....

Re: e-Buggy: Alternator Conversion

Posted: Thu Apr 22, 2010 5:41 pm
by grindz145
John500 wrote:We used automotive alternators for years to put out 117V to run small power tools. They will produce 1Kw but they will get hot in continuous use. With additional cooling, who knows what they will live with?
I'm in Vancouver for a few days next week and will look around the e-bike shops for some parts.


This is an awesome baseline. I'm guessing most of the heat is attributed to current. So if they can be ran at say 200-300V ( :twisted: ) They could conceivably push a lot of power. I'm very much itching to use this as my first IGBT based controller project...

Water cool that little bad boy and have an 8Kw motor with monster torque... for 25 bucks investment (and a ton of time) : that's my dream anyway

Re: e-Buggy: Alternator Conversion

Posted: Thu Apr 22, 2010 8:37 pm
by salty9
INeptOne at RCGroups has an interesting analysis of a Denso alternator at:

http://www.rcgroups.com/forums/showthread.php?t=1123956

Re: e-Buggy: Alternator Conversion

Posted: Thu Apr 22, 2010 9:08 pm
by grindz145
salty9 wrote:INeptOne at RCGroups has an interesting analysis of a Denso alternator at:

http://www.rcgroups.com/forums/showthread.php?t=1123956


3.2 Kw from a $30 'motor' Awesome. very nice link.

Re: e-Buggy: Alternator Conversion

Posted: Sun Apr 25, 2010 5:23 pm
by dajsinjo

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 12:41 am
by widodo
I'm back :D

@Magnus: Welcome, hope you could work your alternator as directed by daj

@dajsinjo: congratulation, seems the 200A controller works flawlessly, perhaps we should list down all the controller that has been proved to be working. Do you have any problem in starting it up ?, what is the lowest rotor supply for a reliable start up ?

@fligh-high: In my ND35, there are 4 wires coming out, but a simple test with ohm meter shows that one of them is the point where all other three connected hence, its was a 3-phase Star wired.

Anyway, while waiting 9 hours jet lag to wears off, Vytis (my 4 YO son, the owner of the buggy) and I start to disassemble our 80A Bosch alternator to install the hall sensor.
Image

I'm planning to wired it as Delta for bigger power, and connected the hall sensor to the RC-standard JST ZH sensor cable, and connecting it to the HK sensored controller.

I will try to have it documented if anybody interested

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 8:52 am
by Harold in CR
The more info the better, widodo. I am headed to Florida on May 10, and, hope to have lots of stuff to play with, there, AND when I get back. 8)

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 12:30 pm
by dajsinjo
widodo wrote:
@dajsinjo: congratulation, seems the 200A controller works flawlessly, perhaps we should list down all the controller that has been proved to be working. Do you have any problem in starting it up ?, what is the lowest rotor supply for a reliable start up ?




I am still waiting for 200A controller

this one was 80A version of the same ( Mystery pentium 80 ) brought by my friend Zoltan

There was a lot of trouble with 12V, it was bearly working, and it worked bether with less power at armature.

on video stator is powered with 24V and there was no problem starting it up !
rotor with 12V, 4.5 Ohm armature resistance + 10 Ohm rheostat, that is 12 to 3.7 V

Alternator is 14V 45A

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 12:32 pm
by dajsinjo
widodo wrote:I'm planning to wired it as Delta for bigger power


I think delta gives higher rpm and less torque, power is the same

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 1:27 pm
by John500
dajsinjo wrote:
widodo wrote:I'm planning to wired it as Delta for bigger power


I think delta gives higher rpm and less torque, power is the same


IIRC Star (WYE) 1.6 X torque of Delta?

Edit; I found many references by searching "delta, star, torque"

Here is one;
"To get a suitable gear ratio, I think you would have to either do a two stage (complicated and less efficient), get an even smaller sprocket (getting hard to find), lower voltage (less efficient, sucks more amps) or or rewire from delta to wye (star) which drops the motor rpm by about 0.57 of original and increase torque by theoretically 1.73, which means you can use some more suitable sprockets (this requires opening up the motor).

Regards,
Martin

EV4LIFE

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 1:30 pm
by Miles
Maximum continuous torque will be the same, though - connecting it Delta means it can run faster for a given voltage and create more continuous power. Maximum continuous torque output doesn't change significantly with the number of turns in the winding, either (assuming equal fill).

We really need to be careful about this, it creates no end of confusion for newbies........

Ref: http://www.rcgroups.com/forums/showthread.php?t=1096719

Re: e-Buggy: Alternator Conversion

Posted: Wed Apr 28, 2010 1:49 pm
by John500
You are 100% correct. I am a newbee and as I live on a steep hill, I was interested in the max torque of a Star to get me home on my first build. I was hoping to not have to change to 20" wheels from 26" if I could figure out how to get the torque and gearing correct for my application.
If there is no torque advantage of Star over Delta, why to industrial applications favour Star for hi torque loads?
Thanks;