In dialing with a rotary dial, a direct-current (dc) pulse produced by a telephone instrument that interrupts a steady current at a sequence and rate determined by the selected digit and the operating characteristics of the instrument. Note: The electrical dial pulse may be converted to an optical dial pulse for signaling in fiber optic systems. See also current,  dial,  dialing,  dial signaling,  dial tone,  direct current,  dual-tone multifrequency signaling,  fiber optic system,  multifrequency signaling,  optical pulse,  pulse,  pulsing,  rotary dial,  signaling.