is it AC or DC

[millwright]

i have several motors but not sure what they are. ac or dc could someone help jogg my memory. some have 2 lead conections and the other has 4 i think this one is ac but not shure.

thanks for any help.

[techman]

Can you open them? Or can you look at the armature inside somehow?

DC motors will have solid magnets inside. AC motors will have an aluminum armature inside.

4 wires could also be a DC stepper motor.

The best way to tell is by reading the label on the motor or looking for magnets.

Also most AC motors have coils on the outside and the aluminum armature spins in the middle.

Most DC motors have magnets on the outside and a spinning set of coils in the middle.

Not always, but most of the time, this will tell you what you have.

[Solar98632]

I have a stepper Motor and it is throwing A/C But mind you it is one of the small stepper motor. I had the volt Meter on DC it didn't register, I placed the volt meter to A/C and spun the thing and yea, it was throwing AC, it has 4 leads and has an upper coil and a lower Coil..Eh well, that is how it appears. I also have some where, a sewing machine motor that is both a/c and d/c when I find it I put a picture up. Not sure where it went.

This is why having a meter is crucial in doing things like this.

[Solar98632]

This motor I have would be damaged if I open it it is sealed and small.. However I can snap a photo of it record a vid showing it is doing A/C.. Think it might be close to 5 V A/C with low rpm. I'll find it and record it as soon as I have completed this sentence. Eh My cam will be reduced to SD (standard Definition) as HD might not fit here.

[Solar98632]

ok here is that motor. As I said it is tiny. but none the less this is an a/c motor..it is some kind of step motor from an older device. I do not remember where it came from. Would this work as a miniature Bedini Motor? It seems to be A/C it has 4 leads. Was thinking of trying it as a Bedini motor. or have you seen this kind of motor before.

[Solar98632]

Here is the video of that motor that is tiny and an a/c maybe I am wrong? Those coils are on the out side
http://www.youtube.com/watch?v=15IMNY_B ... e=youtu.be

[techman]

Ok, your video shows me why you are getting AC. It is a DC motor, but you are spinning it back and forth. One way gives a pulse in one direction. When you reverse the direction, you are reversing the voltage. Try to spin it up in a hand drill in a single direction and you will see DC voltage.

These are hard to work with because you cannot really open them to access the coils.

To make a Bedini motor, you need access to the coils. Each one needs to be separated from the others. Then each coil gets its own circuit. One is a trigger while the others are power coils.

You need to use a motor large enough that you can actually get to the wires and work with them.

[Solar98632]

OUCH, ok I will spin it up with another motor...this one has a permeate magnet on the Rotor?

[techman]

If it generates electricity, then it has permanent magnets in it, yes. Normally on a DC motor tho the magnets are on the casing, on the outside and the coils spin on the rotor, in the middle.

[Solar98632]

Oh this motor has a spinning perm mag that is rotating when I rotate the shaft. the coils surround the magnet..oh and loading that vid as well
I think you will be very puzzled at what you are about to witness.
http://youtu.be/W1mfaluCI_g