| 摘要 |
PURPOSE: To decrease the number of changeover signal lines while keeping a form where the power voltage is supplied to a semiconductor for the switching of input signals. CONSTITUTION: A changeover signal terminal 13 is set in an open state for selection of an input terminal 10A. Thus the PNP transistors Tr 11 and 12 are turned on and off respectively. Then the voltage of 5V of an input terminal 12 is applied to the anode of a diode D11, and the diodes D11, D12 and D13 are turned on. Thus the input signal supplied from the terminal 10A is sent to the circuit of the poststages. When an input terminal 10B is selected, the terminal 13 is short-circuited. As a result, the TR 12 and 11 are turned on and off respectively and the voltage of 5V of the terminal 12 is applied to the anode of a diode D14. Thus the diodes D14, D15 and D16 are turned on and the signal supplied from the terminal 10B is sent to the circuit of the poststage.
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