| 摘要 |
PROBLEM TO BE SOLVED: To expand the input voltage range of an input circuit, without streaming a current equal to or higher than a rating current, to an input device. SOLUTION: With a timing when the base-emitter voltage V<SB>BE1</SB>of a switching device Tr1 becomes a first voltage threshold V<SB>TH1</SB>, input resistance R<SB>IN</SB>is enlarged, thereby expanding an input voltage range, within which a current flowing to a light-emitting device D1 is temporarily decreased and a current equal to or larger than a rating current flows to the light-emitting device D1. As a result, it becomes possible to deal with input voltage ranges of a plurality of types of sensors, without having to stream the current equal to or larger than the rating current to the light-emitting device D1. COPYRIGHT: (C)2009,JPO&INPIT
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