Dimmer switch/pot versus a ceiling fan dimmer

[Gabsonjackellis]

I've heard (im no electrical buff) that powering a motor from a dimmer designed for light bulbs is dodgy.

I'm running a sewing machine motor thru a light bulb dimmer - is this going to be ok in the long run or would i be better shelling out for a more expensive motor-dimmer

I heard something about i damaging the motor too?

what do you guys reckon

thanks in advance!
Jack

[Joe Gwinn]

I've heard (I'm no electrical buff) that powering a motor from a dimmer designed for light bulbs is dodgy.

I'm running a sewing machine motor thru a light bulb dimmer - is this going to be ok in the long run or would I be better shelling out for a more expensive motor-dimmer

I heard something about damaging the motor too?

It's OK to control a universal-wound (AC or DC) motor using an ordinary thyristor lamp dimmer. It works a lot better if you use a diode bridge rectifier between dimmer and motor, especially at low speeds.

Sewing machine motors are universal-wound, but many motors are not, and will not work well with a lamp dimmer. The main test is if the motor has carbon brushes. If yes, dimmer OK. If no brushes, dimmer not OK.

[Gabsonjackellis]

here's a close up of the motor.

http://jacksinstrumentservices.com/s...ne%20motor.jpg

safe or not safe?
what do you reckon brushes or not?

Thanks in advance
jack

[David King]

Jack, that brass block sticking out with the wire attached is one of the brushes, (there should be an identical one opposite it on the other side.) That's a universal motor. Get or build a bridge rectifier that's big enough to handle the wattage of the motor which is probably around 50W if I had to guess. At 240V mains you'd get one that's rated 400V and .25 or .5A

[Joe Gwinn]

here's a close up of the motor.

http://jacksinstrumentservices.com/s...ne%20motor.jpg

safe or not safe?

Can't say, as the photo is too hard to interpret. A few more views would help.