Light generator for HF fibre optics telecommunication system - has summer connected to input via LED with negative variable gain preamplifier and delay circuit with positive variable gain amplifier

摘要

In the light generator for a fibre optic telecommunication system on electrical input signal (2) is passed through parallel paths, one contg. a light emitting diode (D1), a PIN diode receiver (R) and a reamplifier with negative variable gain. The other path contains a delay circuit (LR) and an amplifier (8) with variable positive gain. A summing circuit (S) receives the signals from both paths. The summing cir cuit algebraically adds these signals to provide a command signal to a light emitting diode (D2) whose emission varies linearly with the input signal (2). The diodes (D1, D2) have similar characteristics and the gains of the amplifiers (6, 8) are adjustable for optimum linearity.