| 摘要 |
PURPOSE:To send a current to a half-number of repeaters even when a core is open by providing each repeater with a diode bridge circuit connected on full- wave rectification basis and inserting repeaters into a transmission line in series, and connecting a diode between the output side of the bridge circuit of the repeater at the center position and the ground. CONSTITUTION:For example, the core is open between a repeater Rn and a station B owing to a fault and no current flows. In this case, the polarity of a power unit PFE1 is inverted and then a current flow through a diode D5 connected between the repeater housing grounded by the repeater Rn and one terminal of a repeater circuit power source, a repeating circuit shown by an alternate long and short dash line, and a diode D4. Then, the current flows through a diode D3, repeating circuit, and diode D4 in respective succeeding repeaters and further a Zener diode ZD is connected to supply a constant voltage and a constant current to each repeater. Consequently, repeaters R1-Rn operate an internal fault monitoring circuit and fault searching is carried out starting at the station A. |
