Abstract: An electronic control system for controlling the duration of operation of repetitively activated equipment produces a control signal from input signals representing the values of parameters related to the duration of operation. Timing signals generated from repetitive signals produced by the equipment are digitally shifted through a delay line at a rate determined by the control signal to establish the duration of operation of the repetitively activated equipment. The equipment may include a plurality of repetitively activated mechanisms, such as fuel injectors, which are sequentially selected and activated for the specified duration of operation.

Abstract: An electronic system for controlling the duration of operation of a plurality of repetitively-activated structures produces a control signal representing the duration of operation of the structures from a plurality of input signals representing the values of the parameters which control the duration of operation. The structures are activated by start pulses. The duration of operation of each structure is controlled by the time necessary to drive a corresponding start pulse through a delay line. This time in turn is controlled by the control signal. A plurality of start pulses, each of which controls the operation of a different structure, can be located at different places in the delay line at the same time. The time necessary for each start pulse to travel through the delay line can vary continuously in response to variations in the parameters which control the desired duration of operation. Various circuits are provided to prevent or ensure activation of the structures under special circumstances.