Conditioning electronic impulses for e.g. telephone dialling - uses logic circuit and shift registers to remove contact bounce by comparison of stored and input pulse states

摘要

The method of conditioning electronic impulses removes errors introduced by mechanical contact bounce in telephone dialing appts. and electro mechanical relays. The impulses are sampled to produce a binary output signal equalling the input state. Using storage and logic, an impulse is considered present when two successive samples have been made of a true state and the store is false. The logic then permits successive true samples to enter the shift register store. The impulse is considered to have ended when the store is set true and two successive false inputs have been received. The logic and storage elements may be realised using a microprocessor.