| 摘要 |
<p>PURPOSE:To change a set temperature optionally and to reduce the production cost of the titled device by forming an open drain port in a microcomputer having an A/D converting means and operating the open drain port to form the output of the set temperature. CONSTITUTION:A part 3 to be controlled such as a compressor in an air conditioner 1 is controlled by an electronic control part 2 having a microcomputer 4. To control the controlled part 3, the operation is started or stopped by a temperature detecting circuit 6 and a set value from a set temperature deciding circuit 5 through a comparating part 4f at a temperature between set temperatures T1 T2. At that time, the temperature is set up by an open drain port controlling part 4a and a port switch part 4b included in the microcomputer 4. At the setting, a resistor R1 in the deciding circuit 5 is charged/discharged by a control signal outputted from the control part 4a to a switch part 4b and the states of both parts 4a, 4b are stored and set up in a storage part 4e as set values T1, T2.</p> |
