Triac dimmer circuit for street lighting - saves power and avoids long dark stretches if lamp fails using remote control wire

摘要

The dimmer circuit has a triac in series with the street light's discharge lamp. The triac's gate is controlled from a control circuit that has a control wire for remote control. The output of the control circuit (2) is connected via a feedback circuit (5) to a comparator where it is compared with a signal carried by the control wire. The comparator's output is connected to the control circuit. Each street light has its own triac and control circuit. The advantage lies in saving energy late at night whilst at the same time avoiding the need to switch off, e.g. alternate street lamps and creating dark unlit stretches of road if a light should fail. Dimming all lights saves the same power but avoids long dark stretches if a light fails.