AC, DC, and UNIVERSAL

[LaneFace918]

I met a guy a while back who had wired an AC chop-saw motor on an electric minibike. Was asking him how it was possible for the AC motor to run with the DC power. He gave a bunch of "you take this, n reroute it to her, n instead of..." blah blah blah. I don't remember exactly what he said, probably bc I had no idea what he was talking about. Been searching for a diagram online since, and although I have yet to find said wiring diagram, I have learned a great deal about motors in general. So...
Was the guy just talking out his ass knowing that I'm gullible and/or didn't know any different (?) Or, was the chop-saw a "universal motor" n, maybe he did or didn't know himself, it could be ran either way (?)
If anyone can help me with this so I am able to walk away from it for good, I'd much appreciate it

 

[amberwolf]

Most motors in cheap AC powered devices are brushed motors, which usually have only two wires for input, and they are "'universal" in that they work on either AC or DC. Their response is a bit different depending on the input, but they still work, as-is, no rewiring.

If they're made for AC power, they're also wound for higher voltage than usually used on ebikes and such, so to get the same RPM and power out of it you'd need an equivalent high voltage DC source.

Brushed motors use different controllers than the typical ebike motor (usually BLDC, brushless, 3-phase), or you can use them with a knife switch or other high-current "power switch" to just turn them on and off manually, either full power or no power--but that's harder on the whole system, and harder to control the EV they're on, than using a brushed controller and some form of throttle to modulate the motor speed.

There are other AC motors that are not built in a way that can operate from DC, and any rebuilding to make them do so isn't worth the re-engineering effort unless you simply have no other choice or just feel like learning.

What specific motor do you have, and exactly how do you want to use it, on what system, under what riding conditions/terrain? Those are needed to give you more specific useful help.

 

[amberwolf]

What specific motor do you have, and exactly how do you want to use it, on what system, under what riding conditions/terrain? Those are needed to give you more specific useful help.