Mike you are nearly correct. My Dad had one. It was called an electric pencil. Inside there was an electro-magnet which acted on a spring. This has a clamp for the electrode at one end and the other was connected to the coil of the electro-magnet and thence to a 12 Volt transformer. The other side of the 12 volt transformer was connected to the work piece.

When the point of the electrode touched the work the circuit was completed and the electrode point was withdrawn with a little spark. The circuit was then broken so the point fell onto the work piece and so on.

The device was like a large pen acting not back into the machine like the Burgess unit but at a right angle to the pen handle. It vibrated yeas but not with any force.

The old man uses to use a scrap of 1/16” gas welding rod ground to a point as the electrode.

I think it had a single coil wound parallel to the spring and the whole thing was about ¾” to 1” at its maximum diameter and some where about 9” long. That is all I can remember about it. I think it sort of vanished about 1950.

Why not make your self one.

Regards

Dick

This tool was described in ME around the early 90's ( could have been earlier or later) I think you could do a search

Paul

I seem to remember an artical in ME maybe some time in the 1990s, must have a look.

I'v used the method of attaching one wire from a transformer to the artical to be marked, and the other wire to do the marking. Ian S C

I have a commercially made one. The manufacturer was 'Markem' or maybe that was a trade name.

I could lend it you to copy if you like?

Brian