Simple Divider Yields Low-Frequency Calibration Pulses

A single-stage pulse-frequency divider is presented which operates on 60 Hz to yield low-frequency pulses. The divider exhibits unusual stability against disrupting influences and the resulting pulses have exceptional timing accuracy. For example, the 1-second pulses (division by 60) are reliable over an ambient temperature range of from -40 to + 80°C. Division by 300, yielding pulses at 5-second intervals, is reliable from + 5 to + 45°C. Timing accuracy of the pulses is equal to the average line-frequency accuracy-typically ±0.02 percent.