Special electronic control gear versions enable flicker-free dimming of rod-shaped and compact fluorescent lamps over a wide control range. Dimmable multi-lamp ECG are also available on the market.
The dimming functionality usually serves to increase lighting comfort and energy savings. In contrast to thermal radiators, fluorescent lamps feature nearly constant luminous efficacy over the entire dimming range (cf.chapter on dimming of LED luminaires).This means that it is possible to save energy to the extent the artificial luminous flux is reduced.
Control is implemented via an interface, e.g. for DC control voltage 1...10 V or a digital DALI signal (see also chapter "Light management").
The control gear operates the lamps connected on secondary side according to the signal received at the interface. To this end, lamp current and lamp operating frequency are modified in a way that facilitates ideal gas discharge operation for the desired dimming level. The operating frequency, however, remains in the aforementioned range of 30 kHz to 90 kHz.
New fluorescent lamps must be operated at full luminous flux for the initial 100 hours before dimming, according to manufacturers’ specifications. Otherwise there can be losses in terms of specified useful service life.
When measuring power consumption, it should be considered that a reduced power factor (see chapter ) might manifest in dimmed operation.