| 摘要 |
PURPOSE:To reduce the error of a humidity sensor due to bedewing by a method wherein the amount of saturated steam in a heating chamber is brought to enough high by feeding to a second heating source before a first heating source is fed. CONSTITUTION:When a start signal is inputted to a total heating hour control circuit, said circuit starts controlling and issues each relay drive signal Rs, resulting in putting a relay 25 into actuation and consequently putting a fan motor 9 into operation. On the other hand, the signal of a temperature sensor 19 is inputted to an A/D converter 21. A hour selector 22 reads hours from a hour register 23 in response to the signal from the A/D converter 21 and sets said hours on a timer 24. The hour selector 22 has a function to output zero when the temperature in the heating chamber is in the classified maximum level. When the timer 24 counts down to zero, the feed to the second heating source 17 is stopped and the feed to the first heating source 8 consisting of a magnetron is started. |
