| 摘要 |
PROBLEM TO BE SOLVED: To supply power stably and always to a magnetic recording device by providing a means by which a battery is made a power source and power can be supplied to an external device from a battery connecting terminal. SOLUTION: When a battery 6 is attached to a power source adapter device 1 and nothing is connected to a power source terminal 8 in a state in which a power plug terminal 2 is connected to an alternating current power source, a charging circuit 4 charges the battery 6. The power source plug 2 is removed, an alternating current power source is outputted to the power source adapter 1 through a changeover switch 7, and a power source is supplied to a magnetic recording and reproducing device without cutting off. Then, a voltage value is monitored by a voltage monitoring section 5 to prevent over discharge of the battery 6, when voltage drops lower than the arbitrary voltage, a power source output from the battery 6 is cut off by the changeover switch 7. |
