Control gear voltage or current controlled

LEDOS “classic” circuit board units SELV operation h Various LED power units with and without “intelligence” have been developed in order to allow dimmability or dynamic RGB colour changing as stand- ard. Groups of identical or dif- ferent LED luminaires can either be switched in SELV mode or be selectively dimmed (e.g. as orientation lighting in cinemas, theatres or opera houses). Lighting with dynamically chang- ing colours (RGB) or static set- ting of mixed colours (for a CI, fashion colour of the season, inlay of light in architecture) can be achieved through three- channel or multichannel opera- tion by installing appropriate LEDOS circuit board units are available as 230 V mains volt- age or as 24 V DC models. It is therefore possible to install a lighting point bearing in mind ease of installation as well as the increased safety of protec- tion class III (SELV). Brightness adjustment using Pulse Width Modulation

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F rel

Pulse Width Modulation (PWM) is one possible widely used way of adjusting the brightness of LED luminaires. PWM is used to switch the light on and off at an extremely high frequency. Because it has a relatively slow response time, the human eye is incapable of perceiving the on and off phases. Very efficient low-loss dimming can be imple- mented electronically in this way. All Zumtobel LED luminaires are either connected directly to the mains supply or operated with a SELV supply by using appropriate group control gear. The most important difference in practice is as follows: Mains-operated luminaires are only switchable whereas other luminaires are dimmable and can be controlled with dynamic colour changing. control gear. Decorative LED luminaires with an output of less than 0.5 W are voltage control- led. In the case of powerful high-current LEDs which can project light onto a surface, cur- rent control is usually used.

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p1 red 24 V Manual switch/relay Signal circuit board Red/Greengreen 101010 T D
p1 1 = Tt t
p2 D
p2 2 = Tt

+ ++ 24 V LEDOS circuit board, red/green switchable

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p3 D
p3 3 =t t t Tt