| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a detecting device of high precision and reliability by using a fuse which melts by applying excessive current as a member constituting an input/output signal line to an external device, so that a change of circuit constant is prevented even when an unintended error signal is inputted. SOLUTION: An electronic circuit board 7 is electrically connected to an input/output terminal of metal provided in a connector 5 for connection to an external device such as an engine control device after regulation of circuit characteristics is completed, an external regulation terminal 41 is applied with a DC voltage under which a fuse 1 melts. The fuse 1 melts under the applied current which exceeds a maximum rated value of the fuse 1, and an regulation signal line is electrically disconnected. Since a microcomputer 32 does not recognize applying of DC voltage as regulation signal, no circuit rated value changes. Thus, even if an unintended electric signal is erroneously applied from outside an air flow-rate measuring device whose adjustment of circuit characteristics has been completed, no circuit rated value changes so that a given circuit characteristics is maintained.</p> |
