Light responsive electronic switch - has spectral filter which can measure actuating light magnitude in given spectral range

摘要

The electronic switch is for use as a dimmer for street lighting systems etc. It comprises semiconductor components and a contactor, as well as a spectral filter which can be used to measure a luminous magnitude in a certain given spectral range. The function is reversible by voltage polarisation change and exchanging the transistors (T1,T2). Preferably an inertial photoelement is used for delays in switching on and/or off. Alternatively an RC delay element may be used. A thyristor control circuit may be used instead of the contactor, or in addition to it. The design excludes interference by external light source, while providing automatic switching by a preset luminous magnitude.