Rheostat Switches in Thailand

[Chao Lao Beach]

Hi folks,

I want to make a small electric motor that plugs into the mains run slower and be adjustable.

Can yu easily get Rheostat switches in Thailand ?

Is there any advantage in a switch for variable speed that has indented set points, a bit like a fan ?

SHould I get one on my next trip to farlang land, I can never remember seeing such a thing in thailand,

Thanks

[Crossy]

What sort of motor do you want to control (induction, synchronous, universal)? This is important because some motor types don't take kindly to being controlled.

How big is this motor (Watts / horsepower)? What is is driving?

"Rheostat" (variable resistance) controllers went out in the 1950s (or even earlier) for all but the smallest motors as they are very wasteful of power. Thyristor or Triac controllers are probably what you are thinking of, but they can be picky, hence the previous questions.

This is a rheostat:

[Chao Lao Beach]

I will get more info and get back to you.

"Thyristor or Triac" I presume these ar easy to get in Thailand and i don't need to take a pot luck guess abroad ?

[Crossy]

If it's a small 'universal' motor (has brushes) a nice meaty lamp dimmer (they invariably have a triac controller) will control it just fine. Get them at any DIY place.

If not too big a sewing machine controller would also likely do the trick. That's more likely a Ban Moh (Thip Wari Alley) job, but should be readily available.

[Chao Lao Beach]

click on the thumb nail above

It is a direct drive motor, that has alittle fanbelt that conects to a little grinder.

Here s a pic of the details of it.

Edited October 24, 2015 by Chao Lao Beach

[Crossy]

That looks like an induction motor so you're not going to control it with a triac controller or a 'rheostat', you'll need a VVVF ( Variable Voltage Variable Frequency) drive, not going to be cheap.

EDIT. Actually, as it's only 180W you may score with a fan speed controller. They do tend to make the motors buzz somewhat and are really intended to control motors with relatively constant loads. Can't hurt to try if you can find one rated at 250W (1Amp) or so.