Q. Show the Dialling Circuit?

Dialling circuit enables subscriber to output signals representing digits, and this enables caller to enter destination telephone number. Dialling circuit could be a rotary diallerthat is nothing more than a switch connected to a mechanical rotating mechanism which controls the number and duration of on/off condition of a switch. Though more than likely, dialling circuit is either an electronic dial-pulsing circuit or a Touch-Tone keypad which transmits various combinations of tones representing called digits.