dansawyeror wrote:
Be careful, that is not exactly true. Voltage cannot be created
without energy, it is a force. However once it is 'in place' it requires
no energy to sustain.

A voltage cannot be sustained without energy. The
joule of energy used to create a voltage on a capacitor
is stored in the capacitor until something changes.
--
73, Cecil http://www.qsl.net/w5dxp