| 摘要 |
<p>Apparatus for controlling a heat generator of a heating installation is provided comprising timer means arranged to provide a heat generating signal to generate heat over a first predetermined time period and a heat suspension signal to substantially stop heat generation for a second predetermined time period. The signals may, for example, control the pump of a central heating installation. The apparatus is arranged to provide the signals alternately during a heating period and the frequency of repetition is sufficiently high that, when used to control a central heating installation for a building, a substantially constant temperature of heating is obtained. The lengths of first and/or second time periods may lie within the range 1 to 30 minutes each. In an embodiment of the invention, two frequency selection devices (5, 6) are provided for controlling the frequency of operation of a pulse generator (1). The pulse generator is connected to a pulse counter (2) and means (3) are provided, responsive to the pulse counter, for controlling the frequency selection devices whenever the pulse counter counts a predetermined number of pulses from the pulse generator.</p> |
