An apparatus for metering electrical energy over a predetermined range of voltages within a single meter. The meter includes a divider network for dividing the voltage to generate a divided voltage. The divided voltage is substantially linear with minimal phase shift over the wide dynamic range. A processing unit processes the divided voltage and a current component to determine metered electrical power. A power supply receives the voltage component and generates a supply voltage from the voltage component over the predetermined range to power the processing unit. The power supply may include a transformer having first, second and third windings, so that the voltage component is provided to the first winding and the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current through the first winding. The switch member is operable in response to a control signal, which disables the switch member, that is generated by a controller in response to the output of the power supply.