| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a contact point input device for enlarging a power source voltage range to solve a problem in which a comparison voltage straight line and a contact point voltage straight line are different in inclination thereby the power source voltage range has not been allowed to be enlarged concerning a contact point input device for generating comparison voltage by dividing the output voltage of an external power source and detecting the on/off of a contact point by the comparison voltage. <P>SOLUTION: A constant current source is connected to a connection point of resistances for dividing output voltage of an external power source and generating comparison voltage, and then, a current is drawn from the connection point by using the constant current source. The inclination of a comparison voltage straight line is allowed to be close to the inclination of the voltage straight line of the contact point and also a y-segment of the comparison straight line is adjusted, so that comparison margins are allowed to be equal. Thus, the power source voltage range is enlarged. <P>COPYRIGHT: (C)2012,JPO&INPIT |
