SWITCHING DEVICE FOR COMMUNICATION LINE

• Main Authors: YOSHII KOUJI, OKAMURA KAZUO
• Format: Patent
• Language: English
• Published: 27.11.1982
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

PURPOSE:To enable a communication line to switch not through a power supply of opposing party at a remote control, by charging a capacitor of an opposing station with a DC current transmitted on a spare line and operatng a relay with a discharge current of the capacitor when this current is stopped. CONSTITUTION:In the communicaton of a communication equipment EQ through a line A, a DC current, + for a tip T and - for a ring R is supplied from a station with the maintenance personnel to a spare line B. The DC current charges a capacitor C1 via a switching circuit rl4, diodes D1 and D3 and a rl3 and flows to a diode D2 and a resistor R1 to turn off a transistor TR1. When the changeover from the line A to the line B due to noise, the DC current to the line B is stopped. The D2 is nonconductive, the TR1 turns on, the charge in the C1 is discharged via a latch relay RL to energize the RL to switch circuits rl1- rl4, and the equipment EQ makes communication through the line B. Next, the line A is taken as a spare and a DC current flows to the line A by keeping the tip T as + and the ring R as - and a capacitor C2 is charged via diodes D4 and D6.