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Help identifying small electric motor.

Help identifying small electric motor.

Help identifying small electric motor.

Hi all,

I've been trying for some time now to figure out how and what these motors are.

As it stands I believe they are some kind of 4 pole permanent magnet DC motor with an encoder but I could be horribly wrong.


There are some photos in this google drive folder.

I have a box full of these so it would be great to know what to do with them.

Thanks in advance.

RE: Help identifying small electric motor.

I don't see a permanent magnet.
Does any part of it attract a feeler gage when it's off?

I see six coils on six poles, fed by three wires.
Which suggests that it's a three-phase motor.
... with an encoder attached to the non drive end.

Which comprises, with a separate control circuit board, a brushless DC motor.

You need to find a box of circuit boards with matching connectors or cables.

Mike Halloran
Pembroke Pines, FL, USA

RE: Help identifying small electric motor.

Thanks for that.

The magnets are on the shaft. The grey cylinders.
Image 113543 is the shaft with the magnets and bearings etc.

RE: Help identifying small electric motor.

Yeah, almost certainly a brushless DC motor. It's effectively a synchronous motor, and relies on the external driver to provide the three-phase AC supply to it.

RE: Help identifying small electric motor.

SMI on the label generally means Smart Motor Interface, a standard developed by Moog for controlling servo motors. More people than Moog make SMI compatible motors, but that's a clue that what you have is a PMDC servo motor that can be controlled via an SMI compatible driver / amplifier. Some SMI motors have the amplifier built in, like Animatics, but those look too skinny for that. It's likely a custom OEM motor for a narrowly specific purpose, the pulley on the end suggests a fogged belt, but if it's now totally divorced from its driver you will be hard pressed to find a way to make it work.

"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

RE: Help identifying small electric motor.

Too costly for you to use? Venture onto RE and windmill sites. There is a ready market for this type of motor.

RE: Help identifying small electric motor.

Thanks everyone.

OperaHouse - This could end us being my only option short of recycling them. What would I use to draw attention to them in that circle? Should I call it an SMI PMDC Servo or just a PMDC motor?

I've had a multi-meter across the wires that come off the winding and when I spin the motor I get spikes in the voltage when starting and stopping but nothing during rotation. I was spinning it with a drill so I wouldn't think speed was an issue.

RE: Help identifying small electric motor.

Did you measure AC voltage or DC voltage?

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