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Alien
Apprentice
Canada
149 Posts |
 Posted - Aug 17 2003 : 3:59:34 PM
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An AC motor, probably from a washer came with my new house among other things, i wan't to try to make a go-kart out of it. It seems pretty powerfull and i already tried fixing the lawnmower engine that was also left behing but i didn't come to anything, plus it wasnt horizontal so it would've been a pain in the ass to convert it . So i need a controller, something simple, and i also need ideas on how to power the ac motor. Possibly from a car battery with a inverter? With the electric motor i thaught it might be easier, all i need is the controller, no clutch or anything like that... So is it hard to make a controller??
Andrew
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Andrew
13/m/Canada
EDIT!
I found out that it only goes 1725RPM, not enough is it?... It's really powerfull though, i tried slowing it down with various utilities, including my hands, ouch, none worked... It's really powerfull but not very speedy. Do i need another one or does this one still have a chance
Edited by - Alien on Aug 17 2003 4:33:24 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 18 2003 : 3:36:34 PM
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Well, it's a good idea to use AC, as it's definitly the way to go. All the top electric cars use AC (EV1, TeVan, Tango, etc. etc.). The problem is that this is going to be more of a software exercise then anything else. After all, connecting a bunch of MOSFETs to a microcontroller is easy. Programming the sucker is going to be hard.
It's really simple to build a crappy and inefficient inverter to run that motor. The problem is that you're going to burn most of your input power up in the motor windings at heat.
So, the best choice is to find an AC motor controller prebuilt, or brush up on your C/BASIC and build your own with some type of computer as the brains.
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 18 2003 : 4:54:56 PM
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Aaron, i don't want anything complicated or fancy... Do you think http://www.electronics.50g.com/cacspeed.htmthat controller will work? it seems simple enough...
Edited by - Alien on Aug 18 2003 5:31:38 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 19 2003 : 09:59:58 AM
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The site currently seems to be down. However, remember:
- Your inverter will need to bring up your battery voltage (12, 24, 48,etc) up to 120V/220V for the motor
- If this is a synchronous motor, you need to vary the frequency to vary speed.
- It has to be high current, and have a "soft start" feature, etc.
Not so simple...
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Alien
Apprentice
Canada
149 Posts |
Posted - Aug 19 2003 : 10:10:27 AM
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Actually the link worked it was just me who put that at the end of it... heh http://www.electronics.50g.com/cacspeed.htm
... What do you think
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Andrew
13/m/Canada
Edited by - Alien on Aug 19 2003 10:12:29 AM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 19 2003 : 9:31:00 PM
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Seems to be back up now (before, I couldn't even ping the server).
That circuit is a standard light dimmer type circuit. While it will work for some AC motors (brushed AC motors), it will probably not work for your motor since it is most likely an induction motor. Even if it did, you would still have to provide 120VAC to the circuit. And it would burn most of your power up as heat in the motor windings...For that matter, the waveform from this circuit is also pretty terrible for inductive loads. 
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Kale
Nobel Prize Winner
Canada
795 Posts |
Posted - Aug 19 2003 : 9:48:21 PM
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1700 RPM is pretty good. It's really torque that you're interested in anyway, not speed. If you can't hold it with your hands then I'd imagine this motor is putting out a pretty good amount of torque. With the proper gearing it would probably be fine for a cart or something. Maybe it was a garage door opener? They can be up to 1/2 horsepower or so depending on model.
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cirvin
Nobel Prize Winner
USA
1542 Posts |
Posted - Aug 22 2003 : 8:41:07 PM
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you probably got an extra furnace motor. is it sorta long and grey? anyway, you could get a variac, or ajust the 12v to the invertyer
next stop: nobel prize winner! |
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Another Go-Kart post
