Re: Pulse Width Modulation Speed Control

PWM is a common method used for a lot of different types of electrical devices (tools, machines), Bob.

The home shop type SCR speed controls that many HSMs use, such a KB Electronics use a much higher component count for speed control and regulation, than say, a generic variable speed device like a triac router variable speed device.

The typical basic AC universal motor variable speed circuit may use about 6 actual components.. triac, diac, capacitor (or 2), resistor (or 2) and a speed pot/switch. This circuit may allow the user to change the operating speed, but has no control over the speed regulation at a selected speed.
A KB DC variable speed control with speed regulation may have closer to 80 components not including the internal circuitry of the ICs.

Speed control for single phase AC induction motors involves more functions than chopping the AC supply power.
Oriental Motors of Japan has variable speed modules with speed regulation for their small (up to about 1/8 HP) PSC permanent split capacitor AC motors.

There are other speed control and regulation modules for single phase AC motors, but they aren't common, so the use of DC motors is often an easier/cheaper choice.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Bob La Londe" <nospam@xxxxxxxxx> wrote in message news:gje15s$aa5$1@xxxxxxxxxxxxxxxxxxxxxx
Seems to me this sort of technology would be very affective for any type of motor. Anybody know a good source for one for 110 AC motors? A rheostat type works if its go brushes, but so many motors these days are brushless. Also, because pulse width is always deliverying full voltage (less reaction time of the circuit) it is not as hard on your motor.

I know that Minn Kota introduced it on DC electric trolling motors years ago. How about for AC and/or generic for DC motors?






.

Relevant Pages

  • Re: Cordless screwdriver innards?
    ... >Speed control via a tiny linear pot moulded with the trigger. ... >motors are OK but the electronics are magnificently designed and constructed ... adapted it as a window opener/closer, where it worked well for some ...
    (sci.electronics.repair)
  • Re: Cordless screwdriver innards?
    ... >Speed control via a tiny linear pot moulded with the trigger. ... >motors are OK but the electronics are magnificently designed and constructed ... adapted it as a window opener/closer, where it worked well for some ...
    (sci.electronics.design)
  • Re: Pulse Width Modulation Speed Control
    ... "There are other speed control and regulation modules for single phase AC ... motors, but they aren't common, so the use of DC motors is often an ... God didn't mean for induction motors to have speed control or else he'd a made Tesla a Baptist. ... The typical basic AC universal motor variable speed circuit may use about 6 ...
    (rec.crafts.metalworking)
  • Re: treadmill motor
    ... >Several years ago I bought 2 treadmill motors from Surplus center after ... >motor (I must have used it when the lathe control gave trouble). ... >thinking of getting a Minarik-type speed control for it but I'm ...
    (rec.crafts.metalworking)
Loading