| 摘要 |
An automatic heat control apparatus for use with an electric heating element in a kiln or the like comprises a first power controller having a plurality of on and off intervals. The first controller supplies electric current to the kiln heating element during its on intervals, and further includes means for adjusting the duration of the on intervals relative to the off intervals. A constant speed electric motor is mechanically coupled to the first power controller for gradually increasing the duration of the on intervals and decreasing the duration of the off intervals; such control ensures that the temperature inside the kiln increases very gradually to lessen the risk of breaking the ceramic material being fired. Furthermore, the average speed of the motor may be controlled by means of a second power controller, similar to the first controller, having a plurality of on and off intervals which intermittently energize the motor for rotation thereof. By adjusting the duration of the on interval relative to the off intervals of the second controller, the average speed of rotation of the motor may be selectively varied to control the rate of increase in the duration of the on interval in the first controller.
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