alternator as a motor

[cikljamas]

Hi guys!
I would like to try to move my bicycle with the alternator adjusted to be a motor!
I got normal alternators, and i got repaired alternators with permanent magnets instead of electromagnet on the shaft of the alternator.
So, which alternator is better for conversion in to a motor: ordinary alternator or that one which is repaired with permanent magnets?

And the most important: What kind of controller i have to use to convert alternator into a motor? Could i use some simple electronic diagram or it has to be complicated as professional controllers mostly/always are?

I would like to see some the most basic/simple schematics if someone could link to me which would be able to make a motor out of my alternator. I have tried to find on the web schematics of that type, but i could not find any, is there any particular reason for such absence of these kind of informations on the web or i do not know the magic word that i had put in google search engine?

[citfta]

Difficult project

Hi cikljamas,

It would be very difficult to convert an alternator into a motor. An alternator is an Alternating Current generator that has internal diodes that change the AC into DC. To drive it as a motor you would need to convert your DC from your battery to pulsing DC and the pulses would have to feed into the alternator in time with the position of the armature. You would have to have some kind of position sensor and some fairly complicated electronics to accomplish all this. Why don't you just use one of the little scooter motors that are readily available on Ebay or Craig's list? It would be much simpler and probably a lot cheaper too. If you buy the whole scooter you would even have the control system too.

Carroll

[cikljamas]

Hi Carroll !
I have heard on one croatian kind of energetic forum about so called "sensorless" (for bldc motors) controller that is working with alternators too(and one of the admins on that forum confirmed that), now i wait another answers to my further questions posted to him and others...
The shop where this controller is available is not currently opened because people are on vacation, so i have got one month to build something with my own hands, i just have to know how schematic looks like, for example look at this italian guys project (but there is no concrete information about his electronics, pwm):
Bicicletta Elettrica Video Manuale gratis Kit Electric Bike FREE User Manual - YouTube
This is my ultimate goal:
How to Build a Fast Electric Bike - 50+MPH - YouTube
But first i would like to use my alternator with perman. magnets, and there has to be some easier way to move it, because i saw a lot of performances like this:
Altermotor - YouTube
In this particular video it seems that this guy does not use any special controller, i did not noticed any on his bench...
Or this one:
BLDC motor car alternator - YouTube
I think these guys dont even use alternators with permanent magnets, but ordinary unrepaired alternators, am i right?
If so, my alternator with permanent magnets would be even more effective, because i would not have to spend energy on electromagnet powering.

[vidbid]

Hi cikljamas,

It would be very difficult to convert an alternator into a motor. An alternator is an Alternating Current generator that has internal diodes that change the AC into DC. To drive it as a motor you would need to convert your DC from your battery to pulsing DC and the pulses would have to feed into the alternator in time with the position of the armature. You would have to have some kind of position sensor and some fairly complicated electronics to accomplish all this. Why don't you just use one of the little scooter motors that are readily available on Ebay or Craig's list? It would be much simpler and probably a lot cheaper too. If you buy the whole scooter you would even have the control system too.

Carroll

I don't know about that. I remember as a kid my father showing me a malfunctioning alternator running as a electric motor in his car. The engine was turned off, and yet the alternator was turning and running as a motor, turning the belts. He had to disconnect the battery to make it stop. This was during the decade of the seventies.

[bold_one]

the diodes in an automotive alternator can and have been bypassed, and then all you'll have is the three phase windings like in an ordinary induction motor. just like running a 3 phase motor off of single phase by use of run and start caps, you create your rotating magnetic field. a small field current of milliamps should be used on the armature for torque, a simple 9 volt battery should suffice.

[Peter Kiproff]

Hi Vidbid
Back then we still had generators & if the regulator relay got stuck the generator would spin like a motor.

Cikljamas
Try searching for converting alternator into a stepper motor, I believe you can use 3 transistors to energize each phase in sequence. apply aprox 1A to the field to start.

Peter