| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a DC-DC converter that allows preventing degradation and burning of elements of a bypass circuit from occurring even when a control section outputs an erroneous signal.SOLUTION: A DC-DC converter 100 includes: a step-up circuit 1 stepping up a voltage of a DC power supply 10 and supplying the stepped-up voltage to a load; a bypass circuit 2 provided in parallel to the step-up circuit 1; a drive circuit 3 turning on and off an FET 1 that is a switching element of the bypass circuit 2; and a CPU 4 outputting a control signal for controlling the step-up circuit 1 and the drive circuit 3. A diode D1 is connected in parallel to the FET 1 so that the diode D1 conducts in a forward direction to the DC power supply 10. The thermistor TH1 provided in the drive circuit 3 detects the temperature of the diode D1. The drive circuit 3 turns on a transistor Q1 and maintains the FET 1 to an on-state regardless of a control signal of the CPU 4 when the thermistor TH1 detects temperature greater than of equal to a predetermined value.</p> |
