| 摘要 |
An electronic relay arrangement that is suitable for use as a repeater in systems for single-current as well as double-current telegraphy comprising an input circuit, an output circuit and a transmission circuit interposed between the input and output circuits. The input circuit comprises a current switching device which responds when a threshold current value of the telegraph line current is exceeded and causes a current, having a predetermined constant value, to flow through the transmission circuit. The electrical isolation between the input and output circuits can be effected by, for example, a light-emitting diode in the transmission circuit and a photo-transistor. |
