| 摘要 |
<p>A tumble dryer having an electric heating element 10 switched between first and second states in a regular repetitive cycle. In the preferred embodiment the heating element 10 is switched either fully on or fully off by a relay 24 according to a pulse width modulation control by a microprocessor 21. Advantageously, the effective heater output is continuously variable to any desired level. <IMAGE></p> |
