driving lessons

A title that needs some further explanation. When transistor-transistor or CMOS logic circuits are driven from 50 Hz mains pulses, unsatisfactory behaviour can be expected since the exact pulse shape requirements for proper functioning of the gates cannot, usually, be met by pulses derived straight from the sinusoidal mains. This article discusses those requirements and, taking standard TTL devices as an example, establishes a few basic principles in connection with digital logic driving pulses.