| 摘要 |
PURPOSE:To set optionally a channel number of a broadcast station corresponding to each area by obtaining the correspondence between the channel number setting of a specific broadcast channel with plural variable resistors for tuning and the digital display of said channel number. CONSTITUTION:A control part 10 contains output terminals K1-K12 which are turned on successively and alternatively with operation of an UP key 5 or a DOWN key 6, control terminals a1-g1 and a2-g2 which control each segment of a digital display device 13 for channel numbers, and the terminals for connection of push-button switches S1-S4 which clear or set the channel numbers. Variable resistors VR1-VR12 which are controlled to correspond to the frequencies of different TV channels are connected to terminals K1-K12. Then the voltage of a prescribed level is impressed to a variable capacity diode 1 which varies its capacity according to the voltage impressed via reverse voltage preventing diodes D1-D12 and a trasistor Q1. |
