Lighting control with amplitude controllers

The requirements for tunnel lighting are determined by the nature of the human eye. The tunnel lighting must be controlled such that users, both during the day and by night, can approach, pass through and exit the tunnel without changing direction or speed with a degree of safety equal to that on the approach road.

The lighting of a tunnel needs to be designed in a way that the required luminance levels are achieved at full supply voltage even after aging, soiling and the failure of a part of the lamps. As a consequence not implementing a lighting control system leads to lighting levels too high. Energy is wasted.

An intelligent lighting control system uses stationary luminance meters like JES t/LUM to monitor the actual luminance levels in the tunnel. The tunnel lighting is then dimmed by light controllers until the actual luminance levels match the nominal (required) levels.

Especially in the threshold zone but also in the interior zone substantial savings can be achieved by stepless dimming instead of switching lamps on or off in groups.

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t/DIM-A Amplitude controller

  • Variable electronic transformer to control lighting systems
  • Stepless control of the lamp voltage’s amplitude, i.e. the brightness of:
    • Sodium vapour lamps (high and low pressure), high pressure mercury vapour lamps, fluorescent lamps and metal halide lamps
    • other loads, no matter if pure resistive or with capacitive or inductive components
  • Dimmer control by
    • Floating contacts to activate pre-configured nominal values
    • Analogue value (4-20 mA or 0-10 V)
    • MODBUS, Profibus
  • Configurable burn-in and latency time
  • Configurable rates for voltage increase and descrease
  • Stabilised constant output voltage (compensation of mains voltage fluctuations or load induced fluctuations)
  • Visible status LEDs
  • Basic unit for currents up to 20 A, higher currents possible using intermediate transformer
  • t/DIM-A-20 amplitude controller
  • Intermediate transformer for currents higher than 20 A
  • Optimisation of luminance levels and minimisation of energy consumption at the same time
  • Stepless dimming of lamps by controlling the amplitude of the lamp voltage
  • Stabilised lamp voltage
  • Retrofit to existing lighting systems without changing lamp ballasts or lamps
  • Longer lamp life at reduced lamp voltage
Technical Specifications
Amplitude controller
Type t/DIM-A-20
Operating voltage 230 VAC ± 10 % , 47 .. 63 Hz
Nominal power 4.6 kVA
Output voltage 185 .. 230 VAC controlled
Output resolution approx. 250 mV
Load any, 0.3 ≤ cos j ≤ 1
Temperature range 0 .. 50 °C
Type max. output current Nominal power
t/DIM-A-20 20 A 4,6 kVA
t/DIM-A-32 32 A 7,3 kVA
t/DIM-A-40 40 A 9,2 kVA
t/DIM-A-50 50 A 11,5 kVA
t/DIM-A-63 63 A 14,5 kVA
Mechanical data
Housing material Galvalume®
Protection class IP 20
Dimensions 232 x 130 x 385 mm (without intermediate transformer)
Weight 9.9 kg (without intermediate transformer)
Electrical standards 2006/95/EC Low Voltage Directive (LVD)
2004/108/EC Electromagnetic compatibility(EMC)


Produktinfo DE (PDF, 392 kB)
Produktinfo EN (PDF, 392 kB)