VERFAHREN UND SYSTEM ZUR UEBERWACHUNG VON MINDESTENS EINER LICHTQUELLE.

摘要

The lighting system includes a power supply line with connections at intervals for individual lights. A photodiode detects the light produced by the lamp via an optical fibre extending between the lamp itself and the diode. The diode is connected to an amplifier (11) whose output indicates the state of the lamp. This is connected to a timing module and logic control circuit. In the absence of light, when the power is on, the logic circuit controls an oscillator which produces a note of musical frequency. The output of this oscillator at several hundred Hertz is applied to the power line via a filter in order to be detected remotely.