| 摘要 |
PROBLEM TO BE SOLVED: To enable an electronic control device to accurately detect an abnormal condition.SOLUTION: A temperature detection circuit 14 gives a set signal to a set terminal of a latch circuit 15 when the temperature of an IGBT (Insulated Gate Bipolar Transistor) 13 is above a predetermined value, and the latch circuit 15 gives a cut-off signal to a cut-off circuit 12b. An inverting signal of an ignition signal IGt is given to a reset terminal of the latch circuit 15, and when the ignition signal IGt turns to "L", the latch circuit 15 stops the output of the cut-off signal. An AND gate 19 nullifies the output when a count of a counter circuit 18 amounts to a predetermined value or more, so that even if a detection signal of a current I1 is input from a fail detecting circuit 10, a fail signal IGf is not output during predetermined time or more. An ECU 5 detects the missing of the fail signal IGf. |
