| 摘要 |
PURPOSE:To reduces the cost and to improve reliability with a simple circuit constitution which can flexibly cope with an auto-OFF operation by providing DC-FF with a reset function between an operation switch and a DC-DC converter. CONSTITUTION:When one of the operation switches SW1 is turned on at time t1, current flows via the diode D2 and input voltage becomes L from H. In accordance with this operation, a clock signal applied to a clock terminal of D-FF from the inverter 11 rises to H from L. The FF 12 outputs signal H from the terminal Q in accordance with rising of the clock, and supplies it to the DC-DC converter 13 as a power supply ON/OFF control signal. The converter 13 outputs 5V at time t2, receiving this voltage, and the key microcomputer 14 detects that which switch SW1 is operated in the input port 14b, and an operation program stored in the key microcomputer main body 14a is executed. The command is inputted to the tape processing circuit 15 from the out port 14c and operation processing is executed. |
