| 摘要 |
PURPOSE:To prevent erroneous operation at the time of low temp., by constituting the titled detection apparatus so that the high resistance state and disconnection state of a thermister at the time of low temp. can be discriminated. CONSTITUTION:Even if the resistance of a thermister 1 becomes high at low temp., voltage Vin detected by the voltage drop of a diode 3 in a positive direction generated by a slightly flowing current is not lowered and, therefore, does come to a disconnection detection region even if temp. reaches -20 deg.C. However, if thermister 1 is brought to a perfect disconnection state, no current is perfectly flowed and, therefore, the voltage drop of the diode 3 in the positive direction comes to zero and voltage Vin comes to zero. As a result, the detection of disconnection can be certainly detected. |
