| 摘要 |
There is disclosed a method of controlling an electrical heating element, comprising: maintaining the temperature of the heating element at a target temperature by supplying pulses of electrical current to the heating element; monitoring the duty cycle of the pulses of electrical current; and determining if the duty cycle differs from an expected duty cycle or range of duty cycles, and if so, reducing the target temperature, or stopping the supply of current to the heating element or limiting the duty cycle of the pulses of electrical current supplied to the heating element. As the temperature is maintained at a known target temperature, any variation in the duty cycle or range of duty cycles expected to maintain the target temperature is indicative of abnormal conditions. |
