| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a way to switch a surge absorber circuit to a short-circuited or open-circuited state through a simple operation, and to facilitate conducting a breakdown strength test properly. <P>SOLUTION: A surge absorber circuit board 120 has a protruded portion 140 for an earth connection, which is a non-conductive member. The protruded portion 140 for an earth connection has a screw hole 160 for accommodating a short-circuit/open-circuit setting screw 150 capable of setting a surge absorber circuit 123 into a short-circuited or open-circuited state, as well as a conductive earthing member 170 embedded therein. One end of the conductive earthing member 170 is electrically connected to an earth connection terminal 123E of the surge absorber circuit 123, while the other end thereof has a circular hole 171 which matches the screw hole 160 in size and location and, when the short-circuit/open-circuit setting screw 150 is inserted into the screw hole 160, electrically connects the short-circuit/open-circuit setting screw 150 to the earth connection terminal 123E. An electronic instrument chassis 110 has a threaded hole 113 for the short-circuit/open-circuit setting screw 150 to be screwed in. <P>COPYRIGHT: (C)2013,JPO&INPIT |
