| 摘要 |
PURPOSE:To prevent malfunctions caused by the drop in battery voltage in a portable digital recording reproducing device using a magnetic tape, by inhibiting the output of the AD converter section of the recording system by detecting decreased voltages of the battery and by inserting a noise removing means. CONSTITUTION:Analog signals given to terminals INL and INR are overlapped on TV signal through an analog-to-digital converting circuit 20 and a record processing circuit 21 and recorded on a magnetic tape. Digital signals reproduced from the magnetic tape are given to a terminal INV and outputted after they are converted 26 from digital to analog. On the other hand, the device is operated by electric powers supplied from a battery 41 or an AC/DC adaptor 42 through a power source switching circuit 43. A decreased voltage detecting circuit 46 detects that the battery voltage is the minimum operating voltage at which the device can be operated and performs digital mutings which inhibit the output of the circuit 20. Moreover, a condenser C8 of the circuit 46 removes, for instance, noises from a DC/DC converter 48, etc., as to prevent frequent operations of the digital muting. |
