| abstract |
A vehicle lighting system which provides facility for rearward facing warning lamps such as turn indicators and stop lamps to be automatically dimmed in conditions of poor ambient lighting. Each lamp to be so dimmed has connected in series therewith a switchable device, for example a power transistor, which is caused for normal operation, to remain in a highly conductive state. When the side lamps of the vehicle are turned on, and/or when the ambient lighting falls below a threshold level, an oscillator circuit is energized which causes the transistor to alternate between highly conductive and highly resistive states so as to reduce the electrical energy fed to the lamp. In the event that said lamp is a flashing turn indicator lamp, an expedient is disclosed for causing the flashing rate to remain substantially constant despite the reduction in power consumed by the lamp. |