| 摘要 |
<p>An electronic control apparatus Fig 1 is arranged to cause a ventilator to open or close dependent upon the deviation of the sensed temperature from a pre-selected required value, set at 17. In response to a sensor 10 detecting a temperature deviation greater than a particular amount, the motor of the ventilator is energised in the appropriate sense for a limited period. This period is either manually pre-set at 19 or determined by the apparatus dependent upon the magnitude of the deviation from the required value (Figure 3). If the sensed temperature is greater than the required value by a greater amount, then a circulation boost fan is energised, whereas if it is smaller than the required value by a greater amount, then a heater is energised. Once energisation of the ventilator motor has occurred further energisation thereof is inhibited for a fixed period, selected at 20, to give time for equilibrium to be established. The application to livestock roaring pens is contemplated. <IMAGE></p> |
