Calculators in Timer-Counters for Current Meters

An accurate, compact, low-cost, calculator-based electronic timer-counter for current meters has been constructed and laboratory tested. Electronic calculators often offer an economically attractive alternative to both electromechanical and other forms of electronic counters. The modification of calculators so that they can act as timer-counters is described in general terms. A summary of the results of tests to determine the effect of temperature and voltage variations on the timing accuracy of a prototype electronic timer-counter is given. Laboratory tests were also performed which compared the prototype to two different electromechanical counters in operation. These tests indicated that, with a few minor changes, the electronic timer-counter would provide many advantages over the electromechanical counters.