Distributed signal lamp power supply and control system - uses microprocessor control and voltage sensors to deliver constant power to lamps and indicate failures

摘要

The signal lamp system consists of a l.v. supply from a transformer (1) and a rectifier (2) powering a lamp (3) under control of a semiconductor switch (4). A voltage detector (6) measures the peak voltage. A regulator (5) determines a switch-off time in each half-cycle dependent on the effective voltage measured by the detector (6) to maintain constant power to the lamp (3). Immediately before and after the switch-off time the lamp voltage is measured by voltage detectors (7) and (8) to check that before switch-off a voltage is present and that after switch-off no voltage is present. USE/ADVANTAGE - Control of high-reliability signal lamp installations. Voltage regulation in lamp ensures constant lamp illumination over wide range of supply voltage and distribution networks.