| 摘要 |
<p>PURPOSE:To positively detect the disconnection of contact signal transmission lines, by inserting connecting a parallel circuit consisting of a power source and resistances and polarity relays between terminals at the operation and non-operation sides and a common contact terminal of a tranfer contact. CONSTITUTION:Lines 9, 10 for detecting abnormality are drawn from the terminals 12, 13 of a contact signal transmission circuit device arranged by a transfer contact 1 consisting of a terminal 12 at the non-operation side, a terminal 13 at the operation side and a common connecting terminal 11, contact signal transmission lines 6-8, contact signal receiving relays 3, 4 and a power source 5, and connected to the power source 5 through polarity relays 19, 18. A 2nd power source 15 and resistances 17, 16 with resistance values larger than the internal resistnace of the relays 3, 4 for reception are connected between the lines 9, 10 and the power source 5. If the line 6 or 7 is disconnected under a condition shown in the figure both the relays 3, 4 are dis-energized, and if the line 8 is disconnected the polarity relay 18 is energized, thus allowing the detection of the disconnection of each line 6-8.</p> |
