A presettable multichannel digital timer

A digital timer is described which generates a number of pulses whose delays with respect to a periodic reference pulse can be independently preset by means of thumbwheel switches. The timing intervals are crystal-controlled and can be varied over a wide range--typically 0.1 ms to 99.99 s. It is shown how a pulse train of up to 46 pulses may be obtained, the delay of each pulse in the train being individually presettable. Digital integrated circuits are used throughout, except for the output stage of enhanced drive capability.