Pulse generator for telephone exchange - has oscillator coupled via negator directly and over second negator and delay line to AND-gate

摘要

The pulse generator, for a telephone exchange, has an oscillator (OS) connected to the input of a negating gate (G1) whose output is connected one way directly to the first input of an AND-gate (G3) and the other way over a second negating gate (G2) and a delay line (L) to the AND-gate's second input. The advantage of this pulse generator lies in its being insensitive to variations in temperature and voltage, and to ageing. The two negating gates can be equally well replaced by a single negating gate in series with the AND-gate's first input.