Search found 11 matches

by krumpi
May 12 2010 3:35pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

You are 1year younger then I am! :o I thought about the principle of field weakening used in that patent - compare BEMF and referent value, and if difference is small, field will be weakened, but if difference isn't so small, field will be increased to gain required torque.
by krumpi
May 11 2010 3:42pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Last night (on work :D ) I've found interesting patent related to automatic field weakening, using discrete electronic parts (it's from 1980.!). Think that widodo is using something similar, but with processor.
by krumpi
May 09 2010 2:03pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

At 48V, field connected to separate 12V bat, my setup draws 3.05A. Axle braked with pliers over leather glove (to protect surface) draws not more than 8A, I can't stop it no matter how hard I press. Well, it's on bare axle, 17mm, I know that torque is directly proportional to radius. I have to find ...
by krumpi
May 08 2010 1:15pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

I did some "research", too. Seams that advancing does the same thing as field weakening, but all of them suggest that field weakening or advancing should be done to reach speed above nameplate value, if maximal torque isn't needed. The principle of advancing is - it increases "opposite" BEMF so fiel...
by krumpi
May 06 2010 4:34am
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

I've used simple, experimental method to determine hall position- first manually switched phase sequence to determine "electric degrees" though it was already calculated. Then I've marked static positions of rotor in corresponding stator sequence, and positioned hall sensors according to Microchips ...
by krumpi
May 04 2010 6:24am
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Slight advancing halls is a way to make motor to achieve higher speeds, but current rises, and running in reverse is problematic, because phase shifting comes too late. Advancing is used on rc models, running in one direction, but I think it's not for us on ev. I've used dremel-like tool to make spa...
by krumpi
Apr 15 2010 2:04am
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Yes, dimensions is the right word. :oops: Black hole in my mind is bigger and bigger :roll: :D Interesting, when I write in English, I think in English too, but when it comes to that thing that I can't find the right word, I have a picture in mind, without corresponding word, not in English, but not...
by krumpi
Apr 14 2010 1:24pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Yes, it isn't smaller than alternator used in my current car, and it's rated 75A, and the one I've converted is 42A. Gabarites (LxWxH) is not right word? Or not too often used? Sorry, in every post I have to check my spelling, and my vocabulary is short, although I read English texts a few hours eve...
by krumpi
Apr 14 2010 3:05am
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Good morning! :D
It's a small alternator, it was running on a two-stroker. Small in power, not in gabarites.
Here are my pictures :
by krumpi
Apr 13 2010 2:05pm
Forum: E-Bike Technical
Topic: Unknown controller from e-crazyman
Replies: 0
Views: 243

Unknown controller from e-crazyman

It has 12 fets, but ICs are not from any of controllers seen on forum. I've ordered it 2008., and it was sitting unused till last summer, when I used it for my alternator conversion and experimenting with it. I know it is too weak to drive alternator powered bike or scooter, so it must be moded. But...
by krumpi
Apr 13 2010 1:35pm
Forum: Motor Technology
Topic: e-Buggy: Alternator Conversion
Replies: 145
Views: 48776

Re: e-Buggy: Alternator Conversion

Hello! This is my first post, and I am not trying to steel your thread. I've converted small alternator last summer, but it's still on the table, I have no time to build a vehicle for it. If I saw correct, your (Mr Widodo) hall-sensors are in the "claws" of the stator. My sensors are between claws a...