Technical data

QUICKTRONIC
®
Intelligent DALI DIM | Additional properties of dimmable control gears from OSRAM
37
4.9.1 Falling below the min. dimmer setting at low
temperatures
QTi DALI/DIM operating principle: “Power Boost” and
amalgam lamps
The amalgam releases as much mercury as needed for the
discharge and, as a result, minimizes the drop in luminous
fl ux in hot or cold temperatures. After a change to the op-
erational mode, however, it takes a few minutes until the
mercury balance is readjusted. If the lamp is switched off
for a longer period of time – no discharge and no mercury
needed – the amalgam collects all of the mercury. The mer-
cury defi ciency occurs with a new start, recognizable by
the “pink phase”.
If the lamp is dimmed at this point, its voltage can rise and
the discharge can become unstable. This is where the
“Power Boost” of the QTi DALI/DIM comes into play: It au-
tomatically increases the lamp wattage in order to reduce
the voltage and to stabilize discharge. When the amalgam
has then released enough mercury through the resulting
warming, the output is automatically reduced again and the
lamp remains stable while being dimmed.
The “Power Boost” also works with standard lamps:
At extremely low temperatures, it automatically in-
creases the lamp wattage as needed and always en-
ables stable, fl icker-free operation.
QTi DALI/DIM operating principle with CONSTANT lamps:
Relative luminous fl ux > 90 % over additionally expanded
temperature range of 0 °C to 70 °C.
Standard T5 lamps reach their luminous fl ux optimum at an
ambient temperature of 35 °C – but only if the mercury bal-
ance is not infl uenced by the additional electrode heating.
The QTi-DALI/DIM devices, therefore, have a “cut-off”; i.e.
they switch off the electrode heating when it is not needed.
It is clear that amalgam lamps put out more light at lower
ambient temperatures when the electrodes are heated
slightly. At high temperatures however, this effect is re-
versed.
The QTi DALI/DIM uses its internal temperature sensor to
switch off the electrode heating only when the temperature
is high enough. This allows an additional increase in the lu-
minous fl ux in cold amalgam lamps: The temperature at
which the luminous fl ux falls below the 90-% line falls from
5 °C to 0 °C.
4.9.2 The advantages of amalgam technology
Note:
Dimming amalgam lamps is also suitable for outdoor
applications. It must be ensured that the ECG is suffi ciently
protected from external infl uences (IP67).
“Power Boost” and lamp start with HO-CONSTANT
24-W lamp
Lamp ambient temperature [ °C]
0102030-10 40 50 60 70 80
QTi DALI/DIM: Extremely high luminous flux over an
expanded temperature range
Relative luminous fl ux [%]
0
10
20
40
30
60
70
80
90
100
50
Φ (T) curves of T5 lamps with QTi DALI/DIM
90 % T5 Standard T5 CONSTANT
Lamp ambient temperature [ °C]
Time [s]
-10 0
0
b
a
10 3020-20
-20 20 40 60 80 100 120 140 160 180 200
40 50 60 70 80
Relative luminous flux vs. ambient temperature
in the luminaire of T5 HO Standard and T5 HO
CONSTANT lamps
Relative luminous fl ux [%]
0
0
1
2
3
4
5
6
7
8
9
10
10
20
40
30
60
70
80
90
100
50
T5 HO Standard
T5 HO CONSTANT
ECG power [W]
Rel. Luminous fl ux [%]
The expanded temperature range of the new OSRAM
T5 HO CONSTANT (
b) compared to the T5 HO Standard (a).