| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a feeding circuit provided with a feeding stop function on an overcurrent which can suppress a feeding loss in an ordinary feeding by reducing the number of components. <P>SOLUTION: The feeding circuit 207 provided with the feeding stop function on an overcurrent includes: a first PNP transistor Q1; a second PNP transistor Q2; a third PNP transistor Q3; a first resistive element R1; a second resistive element R2; a third resistive element R3; a fourth resistive element R4; a fifth resistive element R5; and a current limitation resistive element Ra, and the feeding circuit 207 supplies power supplied from a supply power level line Vcc to an external terminal unit (camera attached doorphone slave unit 100), and the first resistive element R1 being an impedance upper resistor of an AC impedance upper circuit A and the current limitation resistive element Ra of a feeding stop circuit B on an overcurrent are characterized in to be integrated into one component as a shared resistive element Rb. Moreover, it is characterized in that a variable resistor is adopted for the fifth resistive element R5 to make an external supply current I variable. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
