Re: Sewing machine motor - reversing direction

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "davep by way of Terry Fritz <twftesla-at-qwest-dot-net>" <davep-at-quik-dot-com>

Tesla list wrote:
> 
> Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
> 
> Hi:
> 
> Has someone found uses for common sewing machine motors in
> Tesla coiling?
> 
> But specifically, I would like to know how to reverse the
> rotation direction of one that I have here. I plan to use it
> to drive a static machine, but observed that it is rotating
> in the wrong direction for my plans. I didn't open yet one
> that I have here to see what is inside. The motor is powered
> by two wires, at 110 V AC, one of them passing through a speed
> control device that appears to be just a pressure-sensitive carbon
> resistor.
 
> I imagine that it's just a question of reversing the connections
> of the brushes, but would like to know if only this works.

	Probably.
	The usual sewing machine motor is (technically) a series,
	commutator motor, sometimes called a 'universal' motor,
	as it will run on AC or DC.  To reverse such a motor,
	one needs to reverse the field OR the armature (rotor)
	polarity.  Reversing the brush connections, as proposed,
	should do this...

	best
	dwp