Daylight controller for LED streetlamps


The danish company CompLED ApS, which sells their own LED streetlamps, based on wellproven LED modules from Osram, wished to add a daylight controller to their existing lamp design.
There were no existing standard daylight controller, fitting into their lamp, either mechanical nor functionally. Therefore they contacted AKJI, to get their own custom developed daylight control.

There were a number of special requirements for the daylight controller, or the "luxostat" as it were named. Offcause it should adjust the light intensity of the LED modules continuesly, dependent of the daylight contribution. So that when the lamp is turned on, it only uses the amount of light required, to maintain a preset lux level on the street, and thereby safe energy. Furthermore its physical dimensions were strictly limited, because there were very little available free space inside the lamp housing. The Osram LED modules, which are used (STREETlight Advanced og STREETlight Protect), should be connected directly to the luxostat. Finally but not least it should be designed to withstand all weather conditions in the top of a streetlamp, all days of the year, many years forward.

The solution became a tiny specially designed transparent box measuring 70*20*12 mm, produced in injection molded plastic. See the picture to the right.
Molded into this, is a little PCB with: Connectors for connecting the power supply and the LED modules, switches for selection of the applied LED module type, and a knop to adjust the required lux-level on the street (the setpoint). On the back of the PCB, the outside of the luxostat, theres is a lux-sensor, and a tiny microcontroller (Atmel AVR ATtiny).

If you need help for development and production of electronics or controls for your product, then please contact Allan Krogh Jensen, and get a free offer.


Osram STREETlight AdvancedOsram LED module used for installation into streetlamps


The CompLED Luxostat module

The completed luxostat module, ready for installation into a streetlamp