re: #183 Guanxi88
Also, remember that you must never close the arc-gap completely, or you’ll fry your transformer.
On that last note, remember that a lot of the older transformers - all of them long gone now, I’m sure - were filled with a synthetic oil coolant, which WILL smoke and burn if you close the gap completely, and that it’s impossible to conceal the resulting fire from your parents in the front of the house.