| 摘要 |
PURPOSE:To estimate correctly the temp. of an electrical appliance even after a power source being turned on again by utilizing the detecting circuit detecting a current flowing to an electrical appliance and the signal transmitted from a discharge circuit having desired discharge time constant. CONSTITUTION:A discharge circuit 4 having about the same discharge time constant as the temp. time constant of an appliance is provided to an electrical appliance, for instance to the device equipping with a detecting circuit 1 detecting the current of the armature coil of DC motor and a microcomputer (micon) 2 estimating a temp. with the prescribed calculation. The micon 2 reads first the output signal of the circuit 4 with A/D converted at the time of a power source being turned on and estimates the temp. of the appliance with the data thereof as an initial value. When the power source is then turned off, the signal related to the estimated temp. at that time is impressed to the circuit 4 with D/A converted 3. Now, when the power source is turned on again after some hours, the output signal of the circuit 4 is impressed to the micon 2 with A/D converted 5. With the use of the signal thereof and the signal which is from the circuit 1, the temp. of the appliance thereafter can be correctly estimated by the prescribed calculation. |
