What's the electric device that allows one to vary the speed of a motor?

[Seb Palmer]

Hi

What's the name of the electric device that allows one, amongst other things, to vary the speed of a motor? I've seen them in YouTube videos where 'makers' use them to operate gear at speeds the machines themselves won't allow.

Thanks in advance,
Cheers,

Seb

 

[marcros]

I think you are thinking of a vfd- variable frequency device.

But there is a lot more to it than that, they won't work for just any motors.

 

[clogs]

they basically use a 3 phase motor which can have speed variation from a 240volt sockets....
it's done by fancy electronics.....
wood n metal lathes use them a lot.....
the full kit is never cheap and also depends on how much horse power you need....
I have a 3HP motor on a big wood lathe......
Hope this is what you mean....

 

[Seb Palmer]

Aha, as A. Partridge once said. Yes, VFDs, that's what I was thinking of. Thanks guys.