IMPIANTO DI COMANDO,DI POTENZA A FREQUENZA DI RIPETIZIONE DEGLI IMPULSI VARIABILE PER APPARECCHIATURE IMPIEGANTI ELEMENTI AD ELEVATO ASSORBIMENTO DI CORRENTE

摘要

A power control system is disclosed for controlling the power output of a resistive heater element in response to operator selected power level settings by varying the rate at which a power pulse of constant duration is applied to the element. The system includes circuitry for generating a control signal representing a selected power output for the element, circuitry for identifying recurring patterns of a binary counter, the patterns recurring at different rates, and a logic arrangement for uniquely associating each of the patterns with a selected power setting. The binary counter and the power pulse control are synchronized with the power supply to trigger a power switching device at or near zero crossovers of the supply.