| 摘要 |
PURPOSE:To make it possible to receive a channel that corresponds to loaded data, by making an automatic return to the last channel a fixed period later when a look at another channel is taken temporarily. CONSTITUTION:Up to time T1, the 2nd channel, for example, is watched and at time T1, switch Sw is turned on. In consequence, the output of inverter 21 changes to ''1'' and rise signal P22 is led out of differentiating circuit 22 and received by memory 23 to store the contents of the 2nd channel. At point T2, switch S7 of a program on a different channel, e.g. the 7th channel is turned on to operate transistor Q7 on electric power voltage Vcc via resistance R7, thereby sending a channel selection voltage to tuner 2 by way of emitter follower TR. At time T3 a fixed time later, on the other hand, monostable multivibrator 24 of resetting circuit 20 is put into operation, so that the 2nd channel can be received again which corresponds to the loaded data. |
