Digital constant-percent break pulse corrector

摘要

Constant-percent break pulse correctors ensure that the break interval of a dial pulse signal subsists for a substantially constant percentage of the total dial pulse interval, i.e., break interval plus make interval. The pulse corrector also delays via an operate timer and a release timer initiation of pulse correction cycles and other supervisory functions. Erroneous generation of corrected output dial pulses is effectively eliminated by completely isolating the release timer from the pulse corrector and by controlling the operate timer to generate a single narrow output pulse for initiating only one pulse correction cycle during each valid operate interval. The pulse corrector employs a control arrangement in conjunction with a counter to initiate a pulse correction cycle upon detection of a valid operate interval. Detection of a valid operate interval by the counter reaching a first maximum count also causes the counter to be set to a second count lower than the first maximum count and to be inhibited from counting up until the counter reaches a prescribed initial count. The time interval required to reach the prescribed initial count from the second count is sufficiently long to prevent initiation of erroneous pulse correction cycles in response to noise. The pulse corrector is capable of detecting dial pulses having a predetermined make interval.