Strippng enamelled copper wire just before termination to transformer pin?

[treez]

Hello,
We are winding flyback transformers with 0.4mm enamelled copper wire.
When one has finished winding a layer on the former, and wish to terminate the enamelled copper wire to a pin, how do you strip the wire of the insulative coating so that you can solder it to the pin?

We are "stroking" the wire repeatedly with a solder iron tip until the insulative coating strips away, but this is fiddly, ...is there a better way?

 

[ravindragudi]

My lab technician uses a sharp knife (lab use) and does it well ..

 

[FvM]

It depends. Preferably use solderable magnet wire. Otherwise special tools like wire scrapping tweezers, e.g. Bernstein 4250838506113.

 

[treez]

Thanks, I thought of using a knife or the tongs, but as you know, when one is just about to terminate the completed winding, there is only a little stub of the enamelled copper wire to get to, so using a knife or tongs in such an area is difficult, the solderable enamelled copper wire sounds good, but this seems too rare and unavailable.

As you know, the normal way to strip ECW is a solder pot, but the small stub of ECW means that we cant get a solder pot to it.

 

[BradtheRad]

I like to use a small sharpening stone. It has a fine grain which makes it more effective than sandpaper or a razor blade.

Some recommend burning away the insulation with a match. I think this is messy, and weakens the copper.

 

[chuckey]

Just about every transformer around seems to have their wires terminated with zero free length to the moulded in pins. I think the secret is to provide the maximum area of stripped copper with the minimum amount of effort. I would wrap the wire around the pins three times, then cut of excess. Run a craft knife or wet and dry paper around the outside of your turns, in the same direction , so you are tending to tighten the turns. Put a little flux on the turns. get a soldering iron with a flat spade tip, hold it at an angle of 45 degrees to the horizontal and apply some solder to its upper surface. Apply your pin to the iron , as soon as a burst of smoke comes off the pin, feed in a little solder and remove iron.
Its a long time since I did this, but its not too hard to do and yes, it's fiddly.
Frank