An there's the rub. You THOUGHT, but not quite long enough. It's ok you are the very first one to ever say that. If you keep walking you will fall off the edge.
I really thought this forum after all these years had finally turned the corner. It's stereo equipment. We (mechanics) put them in the dash of vehicles and install generators as big as a pickup truck to power 400 stereos as CES. I work the shows that supply the power for the equipment. DC? That is just one side of most heavy equipment..
Mechanics PLAY with stereo equipment. I can honestly say, most first year apprentices have enough skill to be a very good stereo repair person. He/she only has 3 more years to Journeyman (to be a mechanic), one more for Aviation or Marine and then 2 more for his masters.
DC is HARD it stumps more people than you think... Most AC guys haven't got a clue with marine electric. AC/DC.
Most mechanics I know were building amps as kids and cars as teens.
BTW it does the Cha Cha 50 OR 60 times per second. You stand still when you dance? That must look weird. :-) The Conga line MOVES forward and then back, just like AC, always towards the source.
AC on the outside, DC on the inside. That was a tough one to learn..