| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a back-up power supply device that can reduce power loss of a back-up power supply and that can achieve size reduction, weight reduction, and low cost. <P>SOLUTION: A control device 4 changes an FET 6 and a relay 15 simultaneously from "off" operation to "on" operation to start supplying of back-up power, when it detects that the power source voltage of a main battery 30 has dropped below a minimum operation guaranteeing voltage Vth of a control unit 50. At this changeover, the FET 6 is instantly stabilized into the "on" operation state, but the "on" operation of the relay 15 is stabilized, after chattering has occurred. The positive voltage terminal 2a of a sub-battery 2 is made conducting with an output terminal 10 via a parallel circuit consisting of the FET 6, a diode 7, and the relay 15, but the back-up power from the sub-battery 2 is supplied to the control unit 50, mainly via switch contact points 15a, 15b of the relay 15. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
