Telephone exchange equipment multi function key - has special outputs from integrated circuits for repeated functions

摘要

Multi-function key is for use in a private branch exchange. The private branch exchange incorporates electronic processing units and electronic memory. These are formed by integrated circuits. The multi-function key repeats telephone numbers and teh repeat function is obtained by depressing the key twice. Each time the multi-function is pressed for the first time it will break the established telephone line connection. Multi-function key us applied partic. to the telephone selection IC type AY-5-9100 using special outputs from this type of integrated circuit for the repeating function and key can be repeated indefinitely and each time it is operated for the first time, will introduce an odd control number in the control circuit. Each time it is operated a second time there will be an even control number in the repeating cycle.