| 摘要 |
<p>PURPOSE:To prevent batteries from being consumed when left turned on by mistake by turning on and off a transistor (TR) switch every time a nonlock type power source and play switch is pressed, and turning on and off the power source through one switch. CONSTITUTION:When a power and play switch 10 is pressed, the capacitor of a control power source holding circuit 13 is charged and a JKFF12 is initialized. Then, a terminal CK is held at a high level through a chattering preventing circuit 11. While a terminal CLR is at a low level, a terminal Q' of the FF12 is held at the high level without reference to the states of other terminals and a TRTR2 and then a TRTR1 turn on successively to supply currents to a motor 14 and an amplifier 15. When the switch 10 is pressed, the terminal CK of the FF12 is held at the high level and the terminal Q' is held at the low level to turn off both the TRs Tr2 and Tr1. When recording and reproducing end and an auto stop switch 16 turns on, the FF12 operates similarly. Consequently, one switch performs sufficient operation and while the constitution is reduced, the unnecessary consumption of batteries is prevented when the switch is left turned on by mistake.</p> |
