I assume AC is even easier, but in DC, splitting a 24V supply into 12V and -12V is trivial. Voltage is just your distance from ground, and while we generally t

I assume AC is even easier, but in DC, splitting a 24V supply into 12V and -12V is trivial. Voltage is just your distance from ground, and while we generally think ground has 0 volts, really it can have any number of volts, just whatever circuit you're running is higher. Voltage is relative to the ground potential. To put it another way, voltage is pressure in flowing water. If you pick a river as "earth" 12V is whatever 12V is in speed faster than the flow of the river, and -12V is going the same amount slower than the river. The river is your ground potential