Photoelectric control unit with cooling chamber

Abstract

A photoelectric control unit for street lighting comprises control means including a photoelectric sensor mounted on a printed circuit board for switching on a street lamp when the intensity of light falling on the sensor falls below a preset value. Electrical connection means between the P.C.B. and the lamp is provided by three connector pins which are led through a cooling chamber or stem. The pins are cranked to closely follow the contour of the chamber to dissipate heat through the chamber walls. The chamber is also filled with a high thermal conductivity potting compound for heat transfer to the walls of the chamber. One controller for such a photoelectric control unit includes a switching means provided by a relay and a triac connected in parallel. The triac operates to prevent the relay being subjected to high voltages during switching and hence prevents pitting of the relay contacts.

Dependencies are inferred from the claim text.