This issue is sponsored by the Philips Romania, Lighting Division

Information
Figure 2 Airfield lighting system (heliport) block diagram with VHF wireless remote control unit [6]
2 Constant current regulators solutions
Classic solution
In classic variant [1], the power part of
the CCR is by thyristor phase shift
electronic switching control (Figure 3).
Figure 3 Diagram of the AC thyristor controller
The dependence of the output voltage
harmonic content of the thyristor phase
shift switching is presented in Figure 4.
The classic system [5], working by
Oradea airport, is composed is in
conformity of Figure 1 diagram and that
concerns: the light fixtures and PAPI
modules, the until 20 kW power CRR’s
with 5 intensities levels and communication
interface, and the remote control unit for
Figure 4 The output voltage harmonic content of the
AC thyristor controller.
transmission of the serial signal (RS 485).
The system interface indicates real-time
airfield lighting status and allows users to
program automatic and pilot controlled
lighting options. The airfield lighting
system poster is in Figure 9 presented [6].
The great disadvantage of this solution is
the accentuated dependence of the output
power and of distortion factor by the phase
shift angle . Expensive auxiliary
equipments are necessary for the reactive
power and harmonic content compensation.
INGINERIA ILUMINATULUI 18-2006 51