The ECM circuit consists of four sections, as shown in the block diagram. A power converter generates a voltage that is proportional to the true of real power consumed by the load. That voltage feeds both a bargraph and a voltage-to-pulse converter. The bargraph gives an approximate indication of the amount of power used, and the voltage-to-pulse converter produces a pulse whose frequency is proportional to the power. The pulse triggers the counter module,
which displays the cost of powering the monitored load.