| 摘要 |
PURPOSE:To attain miniaturization by converting a decimal contact number selected by a switch into a binary number and realizing a switch contact number converter with a ROM to attain the converter by one IC. CONSTITUTION:Any of contacts 1-9 of a rotary switch is grounded by a brush and a grounding point of input addresses A0-A8 has 0 potential. Thus, as shown in a write table, a level 1 is issued from corresponding output terminals 01-04, the level 1 (at normal state) and a level 0 (at abnormity) is outputted from a terminal 05 so that a binary number of 1-9 is obtained in correspondence to an input address with level 0. Then only the ROM 50 is used to obtain an binary output from the terminals 01-04 corresponding to a decimal contact number selected by the brush and mis-selection representing the position of the brush between contacts is displayed from the terminal 05. The switch selection number converter is constituted by the ROM only and miniaturization is attained.
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