6.3V is the standard voltage of a farm tractor battery --these vacuum tube heaters were designed to use them.
12.6V is two farm tractor batteries (one car battery), which is why our computer industry uses 12V for motherboards (12 volts - 0.6V reverse protection diode).
Early computer power supplies used voltage regulators that were designed for car radios, originally.
12.6V is two farm tractor batteries (one car battery), which is why our computer industry uses 12V for motherboards (12 volts - 0.6V reverse protection diode).
Early computer power supplies used voltage regulators that were designed for car radios, originally.