Abstract: A novel electronic timing apparatus is described which contains means for selecting a preset time interval and means for selecting an actual interval to be timed which is equal to or less than, and also a function of, the preset interval. When the apparatus begins timing an actual interval, a first energy source is activated and a second energy source is deactivated. When timing of the actual interval is completed, the first energy source is deactivated and the second energy source is activated. The appartus is powered by a power supply means which furnishes a regulated direct current to integrated circuits requiring such and furnishes line frequency current to other circuits. It also contains means for generating and shaping periodic pulses from line frequency current to form an electronic time base signal for its operation.