Abstract: Time switch is arranged on a plug-in unit for a system housing containing various side-by-side unit components. The time switch includes a rotatable timing disk disposed for rotation about a lateral axis longitudinal of the housing and having a circumferential portion exposed exterior of a front plate of the plug-in unit. The disk is circumferentially formed with time range scale markings and has adjustable switch riders attached along the circumference for selectively triggering control switch as the disk rotates.

Abstract: A cycle control timer unit in which a rotatable annular program carrier is provided having two opposed sides, each formed with a different range program scale and having a different drive coupler means. The unit includes two different rotary drive transmission wheels facing in one direction and rotated at dissimilar speeds respectively adapted for drive connection with the drive coupler means. By flipping over the sides of the program carrier in the unit and connecting the appropriate drive coupler and drive wheel, an operator may easily switch between the different program ranges for control of the unit.