| 摘要 |
PURPOSE: A power circuit is provided to be capable of reducing a fabrication cost and of simplifying a fabrication process, by using a unified power supply part. CONSTITUTION: A power circuit comprises a power supply part(21) which consists of 7805 IC(47) and converts an input voltage into a constant DC voltage. The first resistor(R1) has one terminal connected to an output terminal of the 7805 IC(47) and the other terminal connected to a remote signal. The first transistor(Q1) whose base terminal is connected to the remote signal performs an on operation when the remote signal is high. The second resistor(R2) is connected between the output terminal of the IC(47) and a collector terminal of the first transistor(Q1). The third resistor(R3) has one terminal connected to the output terminal of the IC(47). The second transistor(Q2) has a base terminal connected to the other terminal of the resistor(R3), and performs an on operation according to a voltage of the collector terminal of the first transistor(Q1). An appropriate voltage generating part(100) converts an output voltage of the IC(47) via the third resistor(R3) into an appropriate voltage, in case where the second transistor(Q2) is turned off.
|
