| 摘要 |
<p>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 energise 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 energised the conductors (130, 132) are energised in accordance with the setting of a respective one of the switches. Thus, a desired time-varying pattern of energisation 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).</p> |
