Patent ID: 6140806
Filing Date: 2000-10-31
Classification: G05F,H03K

Abstract:
A power supply control unit having a first semiconductor switch for controlling power supply to a load and a control circuit for detecting an abnormal current in said first semiconductor switch and generating a vibration current by controlling ON/OFF of said first semiconductor switch when an abnormal current occurs so as to shut off said first semiconductor switch by the vibration current,said control circuit comprising:a second semiconductor switch which is connected in parallel to said first semiconductor switch, for controlling power supply to a first reference load indicating a reference value which may reach a maximum value in normal current operating range of said first semiconductor switch;a first comparative means for comparing a voltage on a first terminal of said first semiconductor switch with a voltage on a second terminal of said second semiconductor switch; anda control voltage supply means for supplying a control voltage to the control terminals of said first and second semiconductor switches according to an output from said first comparative means.