| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an input circuit and an input device provided with the input circuit which do not need to replace a substrate in the case of switching over an input terminal to a sink type or a source type, and which are capable of preventing a switching element from a breakdown even in the case of connecting a power source to the input terminal by mistake. <P>SOLUTION: In the case of selecting a sink type input corresponding mode in a DIP switch 70, an FET 31 is turned off and an FET 32 is turned on. In the case where an operator connects an external power source 80 to a second input terminal 22 by mistake, a large current flows into the FET 32. In the case where a larger current than a rated current flows into the FET 32, a fuse 92 is cut immediately. Therefore, the breakdown of the FET 32 can be prevented. In the case of selecting a source type input corresponding mode in the DIP switch 70, the FET 31 is turned on and the FET 32 is turned off, and thereby, an input circuit 1 can be switched over to the sink type or the source type without replacing the substrate. <P>COPYRIGHT: (C)2012,JPO&INPIT |
