| 摘要 |
PURPOSE:To contrive a closing-locked state not to be set, even if service interruption is generated in a section except an allotted section within a timer count time, by contriving an opening lock relay not to be conductively excited after current is released. CONSTITUTION:Unlike conventional circuits, between a closing retaining and reset relay 5, and its first normally opening contact 6, a reverse current suppressing diode 43 is set, and to the closing retaining and reset relay 5, a delay circuit consisting of the series circuit of a resistor 44 and a capacitor 45 is connected in parallel with each other. At the time of momentary service interruption, by the delay circuit, the closing retaining and reset relay 5 is retained. Accordingly, a change-over contact 8 is retained on the side of a normally opening terminal 8b. Accordingly, even if the third normally opening contact 42 of a switch auxiliary-relay 33 is turned ON by the current release of the momentary service interruption, an opening lock relay 13 in not conductively excited and a lock contact 12 is kept in an ON-state. Accordingly, a section switch is not set in a closing-locked state. |
