| 摘要 |
<p>A space heater, designed to maintain the temperature of a room between a lower limit Tm and an upper limit TM, is controlled by a system including a sawtooth-wave generator working by way of a clipping stage into a differential amplifier also receiving a monitoring signal representing the difference between an output voltage of a temperature sensor and a reference voltage. The differential amplifier emits a train of command pulses of temperature-dependent duration which temporarily reduce the mean power of the heater to a fraction of its maximum value, as by periodically interrupting its fuel supply when that heater comprises a gas burner. The heater is cut off for an extended period when the upper range limit TM is exceeded and is then restarted when the temperature falls beneath the lower limit Tm. In the case of a gas burner of the catalytic type, the cut-in is accompanied by a supply of additional gas to the burner for a limited time.</p> |
