| 摘要 |
<p>The controller 20 regulates a boiler 2 having a thermostat 6, fuel burner 4, flow pipe 30 and return pipe 32. The flow and return pipes are preferably associated with a central heating system. The controller is connected to flow 34 and return 38 temperature sensors by respective inputs 36 and 40 and has an input associated with the thermostat and an output for activating the burner, preferably via a control relay 50. The controller also has a memory 44 that stores the sensed temperatures when the thermostat opens, i.e. deactivates the burner. When the thermostat closes, so as to activate the burner again, the controller delays firing of the burner, preferably by keeping the control relay open. The length of the delay is dependent on the ratio of the current flow and return temperatures to their previous, stored values. Ideally, a maximum delay is imposed when there is no change in these temperatures. The controller ideally includes a microcontroller 22, with the relay regulating opening of a fuel valve 12 to control firing of the burner.</p> |
