On December 18, 2010 at 11:33, charris said...
So many competent electricians here - can anyone explain if the above is valid and why? Is it because of the losses? Do you still have losses if there is no lamp load on the transformer?
Have you ever heard of anything that is 100% efficient?
Since nothing is 100% efficient, then the transformer will still have losses, even if no current is consumed.
People think that the 120V 60Hz power in their homes is not being used while they have nothing connected... but that is not true! There is capacitance between the wires, so energy is consumed to charge and discharge that capacitance every cycle. Even the power company's transmission lines and the power distribution in our homes and businesses is lossy.
