Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering...http://www.google.se/patents/US5621629?utm_source=gb-gplus-sharePatent US5621629 - Switching power supply for use in an electronic energy meter having a wide range of input voltages
