Abstract: A time switch (100) comprises terminals (110) spaced around a slip ring (108) connected to a voltage source (V). A motor (104) drives a brush (102) to sequentially connect the terminals (110) to the slip ring (108) to energize the terminals in sequence. Each terminal (110)--as shown for one of them designated 112--is connected via a respective transistor (116) and manually operable switch (124) to a pair of common output conductors or bus-bars (130, 132), whereby for each successive period of time corresponding to each successive terminal (110) being energized the conductors (130, 132) are energized in accordance with the setting of a respective one of the switches. Thus, a desired time-varying pattern of energization of the conductors (130, 132) to accomplish a control function, e.g. the control of a central heating system to provide different heat outputs at different times of the day, can be set up at will simply by adjusting the various switches (124).

Abstract: A control arrangement is provided for a heating system having heat outlets each controlled by a solenoid valve (210). Each heat outlet is connected to a pair of thermostatic switches (411, 413) operative at different temperatures. A time switch included in a central control means (108) is operative to selectively energize a pair of bus-bars (530, 532) at different times, thereby to provide common output signals for actuating the heat outlets via different thermostatic switches (411, 413) at different times to provide different heat outputs during different parts of a predetermined period of time (e.g. 24 hours). The central control means (108) includes a plurality of manual switches (540) each connecting the time switch output bus-bars (530, 532) to the thermostatic switches (411, 413) of an associated one of the heat outlets to manually set the heat output of the heat outlet.