OSRAM DULUX F - Manual (Page 79)

Economical long-life light sources with plug-in bases
Compact Fluorescent Lamps OSRAM DULUX ®
Technical Guide
77
5 Data for control gear manufacturers
Compact fluorescent lamps cannot be operated directly from the mains supply; they need a control
gear. This may be integrated in the lamp (as in the case of OSRAM DULUX
® EL lamps) or may take
the form of an external unit connected between the lamp and the mains outlet (as with all CFLs with
pin bases).
Models with two-pin bases are designed to operate with magnetic control gear; lamps with four-pin
bases are designed to operate with electronic control gear (high frequency operation). In either
case, the operating data of the control gear must be tailored to the lamp data.
5.1 Electronic operation
The advantages of high-frequency operation (BAT) are higher efficiency, longer lamp life, higher
number of switching cycles and more comfortable light than it is the case with choke/starter
circuits. To make best use of these advantages, however, it is important to ensure that the
permissible operating data listed below for preheating, igniting and operating the lamps is followed.
The values in the table apply to an operating frequency of 25 kHz and a sinusoidal voltage during
operation without starting aid.
5.1.1 Preheating (ECG operation)
Starting lamps with filament preheating (warm start) is recommended by OSRAM as the standard
starting procedure. In a warm start, the electrodes are heated by a preheating current with energy
Q
preheat to the emission temperature before the lamp is ignited.
The necessary or permissible preheating current is determined by the design of the electrodes and
the preheating time t
preheat selected. Preheating times of less than 0.4 s are generally not
permissible for compact fluorescent lamps. This is because with such short times it is impossible to
ensure sufficiently uniform heating along the entire length of the electrode. The minimum and
maximum permitted preheating energy can be calculated using the parameters in the following table
for various preheating times. Violating these limit values will cause blackening around the electrodes
and shorter lamp life, particular if the lamp is switched on and off frequently. Compliance with the
prescribed limits is tested on control gear using an equivalent resistor R
sub which is connected to
the control gear instead of the lamp electrodes. The energy fed into this resistor is measured over
the selected preheating time. For the testing of the minimum limit Q
preheat, min a substitution resistor
R sub min is used. For the maximum limit (correspond with a higher electrode resistance) a
substitution resistor R sub max is used.
The minimum and maximum value of the preheat energy is calculated by
Qpreheat, min = Q + Pt preheat
Qpreheat, max = 2 x Q preheat, min
If electrode preheating is carried out with a constant current I preheat or constant voltage U preheat the
necessary current or voltage can be calculated as follows: