| 摘要 |
PURPOSE:To eliminate a channel selecting IC and at the same time to prevent variations of the lock state due to the static electricity, by using a mechanical lock switch. CONSTITUTION:Mechanical lock switches S1-Sn are used for channel selection, and at the same time the end of the other side of the lock switch is connected to the reference point via a switching transistor TR27. Then the TR27 is kept off while the program of a timer 2 is being rewritten and executed (during channel selection by the timer 2) in order to make the switches S1-Sn ineffective. Otherwise the TR27 is turned on to make these switches effective. While channel designating switches A1-An are actuated when the timer 2 is programmed since the mobile terminal is connected to output terminals O1-On of a line decoder 14 and at the same time contacts 1-N are connected to selection lines L1-Ln respectively. |
