| 摘要 |
PROBLEM TO BE SOLVED: To provide an overcurrent limiting circuit which can prevent the damage to an element due to heating at the time of generation of an overcurrent, and also can limit the overcurrent without fail even if one fault occurs. SOLUTION: This overcurrent limiting circuit, which limits an overcurrent, is equipped with first and second resistors to whose one end each the output voltage of an external power source is connected severally, a third resistor which is connected to the other end of the second resistor, a field effect transistor to whose source terminal the other end of the first resistor is connected, and whose drain terminal is connected with an external load, and to whose gate terminal the junction between the second and third resistors is connected, first and second current limiting means to which the other end of the first resistor is connected and which monitor the voltage drop in the first resistor and output signals to switch off the field effect transistor in case that it judges that an overcurrent is flowing, and a logical circuit which puts the other end of the third resistor to high impedance in case that the output of either of the first and second current limiting means is a signal to switch off the voltage field effect transistor. COPYRIGHT: (C)2006,JPO&NCIPI
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