| 摘要 |
PURPOSE:To perform less-error temperature setting operation, by varying control temperature on the basis of an A/D converted digital value. CONSTITUTION:When a power supply switch 6 is pressed while a ten-key on a console panel 7 is pressed, an encoding circuit 8 sets a binary output terminal A at a level H and a binary output terminal B at a level L. A transistor (TR) 9-1 whose base potential is set by the terminal B turns on and a TR9-2 whose potential is set by the AND signal between the inverted signal of the output of the terminal B and the output of the terminal A through an inverter 11 and an AND circuit 12 turns off. A TR9-3 has its base potential set by a signal generated by NANDing output signals of the terminals A and B to turn on and the voltage between a power supply line 15 and the ground is divided by resistance 15 and 16. When the resistance value of the resistance 15 is varied, the varied voltage is converted by an A/D converter 17 into a digital signal, which is displayed on a display 18, setting the control temperature according to the display contents. |
