ABSTRACT
Energy is one of the most important physical quantities in any branch of science and engineering and especially in electrical engineering. The simplest way to perform the energy measurement is to measure voltage and current and then compute the product. The development of electronic multipliers led to their use in energy meters that directly multiply voltage by current. In their first version, electronic multipliers used analog components, while recent devices use digital components and programmable logic systems. The basic blocks of the conditioning system for a dc energy meter are formed from a voltage divider for the voltage input and a shunt for the current input. After these passive components, two preamplifiers are usually introduced before the processing system. The most advanced solution for energy measurement can be found in all-digital meters, where both the voltage and current signals are sampled before any other processing.
