EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: GadgetBoy on March 27, 2019, 11:59:46 pm
-
Just pulled this surprisingly nice reversible AC motor out of a really shitty neck massager - it literally left bruises, which isn't surprising, given the gear ratio it was using. LOTS of torque.
I want to do SOMETHING with it, any suggestions?
P.s. I know the capacitor is what helps it be reversible, but my motor control memory is hazy on why, if anyone wants to refresh me...http://cloud.tapatalk.com/s/5c9c0e466c005/VID_20190327_164856_174.mp4 (http://cloud.tapatalk.com/s/5c9c0e466c005/VID_20190327_164856_174.mp4)(https://uploads.tapatalk-cdn.com/20190327/1e1de0e1e3a7c9563504f601e4bad928.jpg)
Sent from my ONEPLUS A3000 using Tapatalk
-
It's hard to see how it's wired there but if it's reversible then it's probably a PSC motor in which case the capacitor creates the phase shift necessary to set up a rotating magnetic field using the two windings. The direction the motor rotates depends on which winding has the capacitor in series, but without it the motor won't run at all.
-
Or if you like -- one winding can be powered and the shaft won't spin at all (by itself), but it can be started equally easily in either direction with a gentle push.
Mind, split-phase motors aren't made for "impedance protected" operation. You don't want to leave it plugged in and stalled for any length of time, just long enough to demonstrate this, if you're curious. :)
Tim
-
It's hard to see how it's wired there but if it's reversible then it's probably a PSC motor in which case the capacitor creates the phase shift necessary to set up a rotating magnetic field using the two windings. The direction the motor rotates depends on which winding has the capacitor in series, but without it the motor won't run at all.
Forehead smack moment. I even mentioned phase shifting in my video when I took the massager apart (the cap on the motor is suspiciously similar to the ones you find in those power saving scams).
Sent from my ONEPLUS A3000 using Tapatalk
-
Or if you like -- one winding can be powered and the shaft won't spin at all (by itself), but it can be started equally easily in either direction with a gentle push.
Mind, split-phase motors aren't made for "impedance protected" operation. You don't want to leave it plugged in and stalled for any length of time, just long enough to demonstrate this, if you're curious. :)
Tim
I like this idea, I'll have to bodge something together to demonstrate that.
Sent from my ONEPLUS A3000 using Tapatalk
-
Just pulled this surprisingly nice reversible AC motor out of a really shitty neck massager - it literally left bruises, which isn't surprising, given the gear ratio it was using. LOTS of torque.
Aww man, shoulda sent me the massager — that kind of pressure is what I need for a massage to do me any good! :P
-
You could build a small ball mill / drum sander with that motor, if you would like to build something with some kind all day useability. I built one myself some months ago, but decided to redo it since the plastic container I used wasn't anywhere near to being strong enough to withstand the force of my balls.
-
build a tumbler/ball mill for cleaning parts and grinding stuff
I think the sander idea is mechanically complicated since you need to make a good level tray, find a drum that fits the sand paper, dust control (its going to get dust into the motor).
A ball mill requires a decent motor but its going to be sealed and you just need to drive some rollers with a belt and you don't need to build a plate to carry the work piece. And you can get a decent deal for sanders, but a ball mill of decent quality is more expensive for what it is.
You can also make a mod for the ball mill to make a machine that gives you the 'stonewash' finish on gadgets that looks nice and is fashionable.
https://www.youtube.com/watch?v=GYfHmpkXBxg (https://www.youtube.com/watch?v=GYfHmpkXBxg)
https://www.youtube.com/watch?v=L6sgGXXYdEU (https://www.youtube.com/watch?v=L6sgGXXYdEU)