Document UT-MT-0778_EN
Page 18 of 39
Edition 11/03/2014
Supersedes edition 02/03/2014
LED INSET THRESHOLD/END LIGHT L
THE04
INSTRUCTION MANUAL FOR USE, INSTALLATION AND MAINTENANCE
2.3.3
Control circuit
The main task of the control circuit is to assure the correct LED light emission
according to the series circuit current.
To perform this features, the circuit is provided with a current sensor that generate a
signal proportional to the series circuit current.
This signal is analyzed by a DSP which perform a RMS conversion of the input current.
The RMS conversion give a good accuracy with any input current waveform.
Other functions:
diagnostic, auxiliary voltage control and LED status control. In case of any LED
failure or relative power supply circuit failure, the electronic control circuit
commands the intervention of the monitoring device so that the secondary side
of the isolation transformer becomes open, like in the case of an incandescent
lamp failure. This features is essential when the monitoring option is required
events recording (not-volatile memory) for diagnostic purposes
PC operator interface through serial connection: this features allows to calibrate
the brightness depending on the current, to modify the emission curve, to read
the events occurred during the operating time
2.4
ARCTIC KIT
The optional arctic kit is in compliance with FAA “Engineering Brief N°67” document
and it prevents from the ice over the prisms area.
The arctic kit is connected in series to the PCB and it is consists of a thermostat (two
in case of fixture with double cable lead) and one or two heaters. It starts when the
dome temperature is less than about -1°C and turns-off when the dome temperature
reaches about 10°C.
Arctic kit consumption is less than 40 VA per plug.
