A photosensitive electrical controller for street lighting

摘要

An electrical controller for supplying power to a load eg. street lighting, according to the intensity of ambient light as sensed by a photosensor D3. At predetermined thresholds of ambient light a latchable relay RLY is opened/closed by application of a pulse. One embodiment uses a capacitor C1 to supply the triggering pulse. Another embodiment (figure 2) has a latchable relay with two windings that can be alternatively energised to control the load.