I recently moved to Australia from the United States and brought a few stepdown transformers to make use of some appliances I didn't want to repurchase down under.
I have a 2000W transformer that I use for my rice cooker and vacuum and was wondering today if the electricity usage function is
kWh = (Hours used) * (Wattage of transformer)
kWh = (Hours used) * (Sum of wattages of appliances drawing power)
Or possibly neither? At prices up to $0.33 a kWh it's an important thing to figure out!
As well, most of my devices say they operate at 120V but my transformer outputs at 110V, will this cause problems?