Lichtwellenleiter-Übertragungssystem

摘要

The transmission system (1) includes at least one light wave transmitter (2) and a receiver (3) connected to it, via an optical waveguide (4). The feed circuit (5) consists of a transmitting diode which is connected between a supply voltage source and two parallel branches, each containing a resistance and an earthing transistor switch. In normal operation both switches are operated in synchronism, in accordance with the digital signal to be transmitted. In the test mode one switch is held closed while the other is operated at a predetermined frequency, varying the current between its normal value and a reduced (non-zero) test value.