Storage circuit for electronic emergency-call branch exchange - has clock signal sent via delay line to flip flop

摘要

The store circuit, for an electronic emergency-call branch exchange, stores the last two keying operations of the attendant operator and also their sequence. A clock signal is sent via a delay line (311) to a flip flop (312) to allow the information about keying to be accepted by a store (32, 33). The clock signal is applied to the set input of the flip flop (312) and is generated by a binary coder (30) that converts the operated key's signals. The output from the flip flop is differentiated by two differentiating units (313, 314), and the differentiated output is used to free a store (32, 33) for accepting the binary signals from the coder (30).