Residential time-of-use kilowatthour meter

To extend time-of-use (TOU) load management from industrial to residential users, a low-cost meter with capabilities similar to industrial TOU meters is required. A design study uncovered many opportunities for reducing cost and adding capabilities. For example, efficient software allowed the use of a low-cost four-bit CMOS microcontroller, and the low-power CMOS circuits allowed the use of either a non-rechargeable 10-year life battery or a 'supercapacitor' for reserve power during outages. New capabilities included the recording of date and duration of the longest outage and a security scheme to foil tampering. Prototype residential TOU meters were developed and tested. In 1984, the cost of materials for the prototype was approximately U.S. $35 each for a quantity of 5000 and is expected to be significantly lower for production quantities.