Limiter for lamp switches in telephone exchange - has auxiliary capacitor parallel with series combination of pushbutton and self-holding relay to set number of switched-on lamps

摘要

An auxiliary capacitor (Ch1-Chn) is connected in parallel with each series combination of pushbutton (T1-Tn) and self-holding relay (SR1-SRn). - When a button associated with a non-excited relay is pressed the limiter (BA) is not operated and the relay is excited by the charge stored by the first capacitor (C1) and the auxiliary capacitor associated with that relay.