| 摘要 |
<P>PROBLEM TO BE SOLVED: To simplify a circuit structure, without providing an ON/OFF control circuit for each output, in a power supply that simultaneously controls the 'on-off' of a plurality of output voltages. <P>SOLUTION: A first PNP transistor Q1, a first resistor R1, and a first diode D1 are connected in series to the positive side of a first DC power source V1. A second PNP transistor Q2, a second resistor R2, and a second diode D2 are connected in series to the positive side of a second DC power source V2. An on-off control circuit is constituted of a NPN transistor Q4, a third resistor 3 connected to the base of the NPN transistor Q4, and a fourth resistor R4 connected between the base and emitter. The cathode sides of the first diode D1 and second diode D2 are connected to the collector of the NPN transistor Q4, the third resistor R3 is connected to ON/OFF control terminal, and the negative sides of the first DC power source V1 and the second DC power source V2 are connected to the emitter. <P>COPYRIGHT: (C)2003,JPO |
