Footpedal for a sewing machine

Very nice work Don. Although I would recommend replacing the Phillips-head screws with flat-head socket cap screws (either hex or Torx): the socket screws look better and are less likely to snag "milady's sock".

I'm curious though: isn't a Minarik controller overkill for a sewing machine? Wouldn't a simple triac or SCR universal motor speed control work just as well for this application? Something like this:

Regards, Michael

some of the older machines got footpedals though

Cowly the Game player

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Good idea re screws. I'll look for some black flathead socket-head screws. The screws used here are stainless, but they're probably far enough away from the sensor that steel screws won't affect things much.

The Minarik from EBay was only a couple of bux more than the HF control. It works markedly better because it senses motor current and compensates for load. The HF control claims to do this, but it doesn't do it nearly as well. The Minarik is also an SCR controller, but it has a couple of opamps and a current sense resistor as well.

The Minarik is also amenable to control with a varying voltage rather than a varying resistance as a pot.

Depends on the circuitry in the controller. This footpedal produces 0 to 2.5 volts DC, not a varying resistance.

The Hall sensor I used is a Honeywell SS496 ratiometric hall sensor. I don't know if these are still in production or not; I happened to have a few in my goodiebox. Similar current-production devices are available from Allegro and several other vendors.

I'd keep them stainless, not so much because of the sensor, but rather because of perspiration from the operator's foot (I'm sure "milady" doesn't sweat, but everyone perspires). Black oxide won't stand up to that and will discolor socks.

Regards, Michael

For what it's worth, Don got that controller from me - I have more, similar controllers (Minarik MM23012D Controller )at $30 each.

to find them, go to my web page,

click on stuff for sale (or "for sale" on the left hand frame), then choose just about any page (for example, meters, gauges, and controls), then click on the "controllers" link on the top of the page. These controllers are a heck of a lot nicer than the harbor freight controlls.

bill N

Phillips-head