Motor Speed Controller I have a scroll saw that someone was throwing out

[G+_David Peach]

[Motor Speed Controller] I have a scroll saw that someone was throwing out. It seems like the speed controller board has given up the ghost. The saw motor has 4 wires coming out of it (no model number). I applied 12V directly to the motor and it turns, so I don't think the problem is the motor. Which is why I suspect the speed controller.

 

But, I'm confused as to what type of motor I have and what kind of speed controller I need. The motor has 4 wires: 2 yellow, 1 another color and 1 another color. I don't remember the other two colors, but the fact that 2 of them are the same, makes me wonder if the speed controllers I see at eBay are what I'm looking for.

 

I don't have the motor with me (nor the current speed controller) but can snap a picture this evening if it will help.

 

Here is one of the speed controllers I'm looking at. But I don't know if my motor is 12V/24V (and if it matters): https://www.ebay.com/itm/12V-24V-Max-20A-PWM-DC-Motor-Stepless-Variable-Speed-Control-Controller-Switch/111936836128?epid=1462708855&hash=item1a0ff49220:g:REkAAOSwcUBYU0wW

 

Another that I am looking at is rated 9-60V. https://www.ebay.com/itm/9-60V-Max-20A-PWM-DC-Motor-Stepless-Variable-Speed-Controller-Switch/302014786519?epid=920377762&hash=item46517bebd7:g:3nkAAOSw0fhXiKJa:sc:USPSFirstClass!37877!US!-1

 

These both seem really cheap, but seem to be what I'm looking for. As far as the motor goes, it looks something like this: https://www.ebay.com/itm/DeWALT-DW788-DELTA-40-690-RECIPROCATING-SCROLL-SAW-MOTOR-ASSY-286306-00-/321947331282

 

Except that one only has 3 wires (which may be the same as mine with 2 identical wires). Neither the motor I linked to, nor mine, has a start capacitor on it like a larger motor.

 

Appreciate any help with direction.

https://www.ebay.com/itm/12V-24V-Max-20A-PWM-DC-Motor-Stepless-Variable-Speed-Control-Controller-Switch/111936836128?epid=1462708855&hash=item1a0ff49220:g:REkAAOSwcUBYU0wW

[G+_David Peach]

Here's the current motor driver. It is triac based. The two main capacitors on the right looked like they had leaked so I replaced them. Still not working. There are several sketchy looking solder joints that I may just try reflowing everything.

[G+_David Peach]

And the motor and plug.

[G+_Ben Reese]

AC comes to mind when I think of a scroll saw. But then, I wouldn't expect that much circuity to control the speed on an AC motor. Even if it was doing zero-cross detection, I don't think that many electronics is necessary.

[G+_Paul Hutchinson]

TRIACs (triode for alternating current) are only for switching AC at the zero cross point so it must be an AC motor.

[G+_John Sullivan]

You said you "applied 12 v directly to the motor and it turns".

12v AC or DC?

What two wires did you connect to?

If you used a 12 DC power source, just purchase the controller you show in the image, hook two wires to the motor (the same ones you tried earlier) and two wires to your 12 v supply (as you tried earlier) and you are done.

 

If you used a 12 v AC source, then look for an AC speed controller.

[G+_David Peach]

cosmic Ray DC power supply. Mine is variable from 0 to 15V and speeded up as expected with increasing voltage. Input on the red and blue wires.

 

I've ordered an AC speed controller that can be converted to DC with the bridge rectifier that I also ordered. Will see how that goes. But the speed controller linked above seems like a better option if I can hook it up the way you suggest. My current order should be here by Wednesday.