When I was studying electricity and AC/DC I thought of suggesting this.
DC electricity is common unidirectional current which we have today in TPT. Made by BTRY.
AC electricity is the main suggestion here. It is the same as SPRK but changes direction every 2 frames. It still travels forward through wires and goes more in one direction than the other, if you know what I mean.
AC = ASPK
DC = SPRK
BTRY generates SPRK and ACGN generates ASPK.
Hope you like this suggestion and please share your opinion.