Wiring a New Electronic Controller for a Vintage Sewing Machine.
So, why would someone want an electronic controller? Because they don't produce heat as they regulate the electrical flow to the motor. If you have a habit of never completely removing your foot from a mechanical resistor type controller (carbon pile or wire wound type), these controllers can get VERY toasty. Why? In simple terms, they take the electricity that they are not sending to the motor and turn it into heat. So if you leave the controller just barely engaged, it may not send enough power to the motor to actually move it, but it will convert the remaining 99% of the electrical flow into heat. Likewise, if a mechanical resistor type controller malfunctions or isn't adjusted properly, it can get excessively warm, even hot. An electronic controller approaches the regulation of electrical flow differently and eliminates this problem. The down side to the electronic controllers is that they are plastic, and feel flimsy compared to some of the other controllers.
If you do not have the proper tools, knowledge or experience to complete this project in a safe manner, for goodness sake, DON'T DO IT. Never work on any electrical item while it is plugged in to a power source. I am not responsible for any problems that you may encounter as a result of attempting this project. PROCEED AT YOUR OWN RISK.
Do not use any magnetized or magnetic tools in conjuction with the PC board or any of the screws on the PC board. (Many screw drivers have magnetic tips)
For this project, I started with these items- a new electronic controller and a new Singer, double lead cord set.
|There are different styles of electronic controllers. This article will show how to rewire two of them.
The first style is shown to the left and is the easiest to work with. The top screws onto the base, no extra cord strain relief is needed, and it utilizes the more standard ring or fork type wire terminals found on most existing and new cord sets.
|As you can see in the photo, I do add a short length of heat shrink tubing over the cord where it enters / exists the controller body. This is optional, but does give the cord a little extra support and strength.
This style controller is about the same size as the Singer button controller, but much lighter.
|Tools: Wire cutters, wire strippers, wire crimping tool.
To the left - the connector that comes on the new cord set. and one cut wire.
OK, the first thing to do is to remove the terminals from the end of the wires on your cord set. You'll need a "special" type for the electronic controllers (female spade terminal). The controller comes with These "special" terminal ends, but I prefer some that I find at my local hardware store. Either ones will work fine.
|Pop the top off of the controller. Determine how much wire you will need inside the controller. Put the strain relief around the wire at the desired spot and push it into the hole. Implement the required cuss words to get it to fit. Then, connect the wires onto the board inside the controller.|
|Here it is all done, except for popping the top back on. I use the silver colored square-ish piece as a sort of clip to add some extra strength to the security of the strain relief. It just makes it all that much more stable.|
|See how nice that looks? It's all put back together and ready to use.
I have cord sets and controllers in stock at the Sew-Classic Parts & Supply online store, Shop.Sew-Classic.com
Geek type notes:
- The 120 VAC in the USA is a nominal figure and it IS the RMS (root mean square) or effective value.
- Watts = Amps x Volts.