Dimming of amalgam lamps

With QTi (DALI)...DIM

Reliable ignition down to -20 °C
Shorter start-up due to Power Boost
Up to 20 % more light from cold or hot luminaires
90 % luminous flux from ambient lamp temperatures of 0 °C to 70 °C
Optimal lamp operation even at low dimmer settings
- Up to 1 % power at lamps T5 CONSTANT and OSRAM DULUX L CONSTANT
- Up to 3 % power at lamps OSRAM DULUX T/E CONSTANT

Reliable dimming at low temperatures

The burning voltage of a fluorescent lamp rises when dimmed down.This increase is further amplified by low temperatures. Latest with achieving the maximum operating voltage U_out the ECG has to shut-down for safety reasons.
Excessive increase of the burning voltage can also cause flickering. Therefore, the permitted ambient temperature range is limited.

1. Dimmer setting equates to power, not luminous flux!

2. Following table is also valid for QTi (DALI) 3x18 DIM / QTi (DALI) 4x18 DIM /
QTi (DALI) 3x14/24 DIM oder QTi (DALI) 4x14/24 DIM

Dimming of amalgam CFL lamps ORAM DULUX T/E CONSTANT

Stable and reliable dimming operation of amalgam CFL
OSRAM DULUX T/E CONSTANT 26-42 W on ECGs QTi (DALI)…DIM, from 3 % to 100 % lamp power.

Normal light color from approx. 30 % dimmer setting.
At its initial ignition, the ECG-internal „Power Boost“ increases the lamp power. It supports the release of the mercury and stabilization of the discharge.
During the "Pink Phase" at dimmer settings < 30 %, the ECG may intervene in favor if the amalgam lamp is operated unter insufficient gas pressure.

Power Boost and amalgam lamps

The amalgam releases just as much mercury as used for the discharge phase and reduces therefore the decrease of the luminous flux at high or low temperatures in a tremendous way. After a change in the operation mode, it takes several minutes until the mercury balance is set up. When the lamp is switched off for a longer time – no discharge, no mercury demand – the amalgam gathers again the whole amount of mercury. During a restart, there is at first a lack of mercury, being visible by the “pink-phase.”

If the lamp is dimmed during this phase, its voltage can rise to forbidden values. This could lead to instable discharges. Now the focus is on the power boost: The power boost automatically rises the lamp power in order to reduce the lamp voltage and to stabilize the discharge phase. When the amalgam has released enough mercury, the lamp power will be reduced again automatically and the lamp can be dimmed normally.

The power boost works even with normal mercury lamps: At very low temperatures, the power boost raises again automatically the lamp power, if necessary, and takes over the role of the limitation of the dimming level.