| 摘要 |
PURPOSE:To elevate the temp. at each point in a furnace body in a prescribed time without overshooting by stopping once the temp. elevation at the temp. near the required set temp. range in the stage of temp. elevation then elevating the temp. to a prescribed set temp. CONSTITUTION:A relay 6 is energized, upon turning-on of a start switch 1, and conduction of electricity to the 1st heater is started and at the same time a relay 8 is energized so that the conduction of electricity to the 2nd heater is started and the inside of a furnace is quickly heated. A PID controller 9 is inputted with the detected output of a temp. detector 10, and when the output thereof attains the temp. near the lower limit of a set temp. range, a relay 12 is energized and a timer for setting the time for stopping the temp. elevation is set. The conduction of electricity to the 1st and the 2nd heaters is stopped at the same instant but the timer 14 is set and therefore both heaters are turned on and off by the controller 9 and the temp. in the furnace is maintained approximately constant. When the timer 14 times up, the contact thereof is closed and the 2nd heater is again energized so that the temp. in the furnace is elevated to the set temp. range. |
