| 摘要 |
<p>PURPOSE:To eliminate waste and secure safety, by turning off the unit itself and power source circuits of devices connected to this unit when the output signal of a video signal detecting circuit does not exist. CONSTITUTION:When no composite video signal is transmitted to the output of video amplifying circuit 9 through the output of recording and reproducing sequence circuit 12, which the reproducing operation is designated to, is ''L'', the output of signal detecting circuit 11 becomes ''L''. Consequently, two inputs to NOR circuit 13 are ''L'', and the output of circuit 13 is ''H'', and therefore, electromagnetic relay driving circuit 14 is operated to turn off electromagnetic relay 15. As the result, main power source circuit 17, auxiliary power rectifying circuit 18, and AC outlet 19 in the VTR are turned off, and the reproducing mode is stopped. The similar operation is performed in the recording operation also. As a result, various kinds of waste can be eliminated, and safety can be secured.</p> |
