| 摘要 |
PURPOSE:To prevent malfunction by generating a voltage division signal depending on the ON state of plural operation switches and applying matrix processing to a voltage signal at each signal line to specify an operated switch and output a drive signal. CONSTITUTION:When contacts (c, a) of operating switches A1-A16 are closed, voltage division signals Va1-Va16, Vb1-Vb16 being voltage divisions of an output voltage of a positive power supply terminal by resistors 19a, 19b, 19c and a jumper 20c are outputted respectively to lines La, Lb. Comparators 24-27, 28-31 are provided in correspondence to the signal lines La, Lb and kinds of the signals Va1-Va16, Vb1-Vb16 and compare the output of the lines La, Lb and reference voltages VE-VH respectively. The result of comparison is fed to exclusive OR circuit 32-39 and its output is given to a decoder circuit 40 comprising a matrix circuit using lines L1-L4, L5-L8 as rows and columns. Thus, the combination of the signals Va1-Va16 and Vb1-Vb16 is recognized and which of the switches A1-A16 is operated is specified, and a driver 43 is driven. |
