This weekend I rigged up a jacob’s ladder from an old microwave oven transformer. Due to the low voltage (~2kV) it won’t self start. You can see me starting it with a paperclip on the end of a paint stirring stick. Although the voltage is a bit low, these transformers can put out huge current, so the arc is great once it starts.

Playing around with it earlier, I got arcs as long as 10″ from it. Now the search is on for another MOT or perhaps an old neon sign transformer.