Thread: Cheap EVS Alternative.

I seen these advertised in the UK.

Would these be a cheap alternative for a verifiable speed controller on a single phase motor?

If any good any one is Aust making these?

http://www.mcbri.com/revlo/revlo_ele...ontroller.html

Originally Posted by wm460

I seen these advertised in the UK.

Would these be a cheap alternative for a verifiable speed controller on a single phase motor?

If any good any one is Aust making these?

http://www.mcbri.com/revlo/revlo_ele...ontroller.html

Short answer ... No.

Long answer, those type of controllers are for universal motors, like electric drills and routers, they work by chopping the sine wave. The best of that type I know of is the one sold by Jaycar http://www.jaycar.com.au/productView.asp?ID=KC5478

If you want to vary the speed of a single phase induction motor, you need to look for variable frequency like this one...http://www.siliconchip.com.au/Issue/...roller%2C+Pt.1

Bottom line, is that now-a-days you are better off with a three phase motor and a VFD, cheaper and better, what more could you ask for.

Ray

Originally Posted by wm460

I seen these advertised in the UK.

Would these be a cheap alternative for a verifiable speed controller on a single phase motor?

If any good any one is Aust making these?

http://www.mcbri.com/revlo/revlo_ele...ontroller.html

Only suitable for the types of motors commonly used in mains powered hand held drills, angle grinders, routers etc, in other words motors with carbon brushes, which tend to be high speed motors, say 5K RPM and above. For induction motors like the ones used on most pumps, bench drills, power hacksaws, lathes and milling machines etc, it will be of no use. These motors are usually either 2800 or 1400 RPM motors for home applications, being 2 pole and 4 pole motors respectively, but 6 and 8 pole motors may be found in equipment which runs at lower RPM.
There are kits available from firms like Jaycar to build your own speed controller for universal motors.
EDIT. Ahhh too slooow again, and Rays answer is more complete than mine too

Thanks for your replies, I guess I was looking at a cheap option for a little lathe I use for wet sanding and applying CA on pens, I like to put the CA on at a lot slower speed than I sand. Its a pain in the butt changing the belt.
That silicon chip article look interesting but far to complicated for this eletricky challenged bloke.

Look on eBay for invertek optidrive, there is a guy on the USA selling the 240v version cheap. Afaik these are the only commercially available single phase vfds. I have been told though that the huanyangs will run a single phase motor happily but i have never tried it.