Numeric keypad using relays.
(Displays numbers from 0 to 9)
789
456
123
0
It consists of a numeric keypad at the top left, a simultaneous press countermeasure circuit at the top, an encoder at the bottom right, a 7-segment decoder at the bottom center, and a 7-segment display at the bottom left.
It can be used as an input circuit for calculators, etc.
