Economic reasons :

  • Reducing energy costs

  • Increasing lamp life

  • Reducing maintenance costs

Ecological reasons :

  • Reducing energy consumption


User comfort :

  • Constant level of brightness

  • Creation of lighting effects


Safety reasons :

  • Easier adaptation for the human eye between different levels of illumination


The commonest types of lamp on the marketplace can be dimmed in a variety of ways:


Thermal radiators

Lamp

Dimmable

Range

Technique

Notes

Incandescent lamp

yes

100% - 0%

Phase-lead, potentiometer

%

High voltage-
tungsten halogen lamp

yes

100% - 0%

Phase-lead, potentiometer

%

Low voltage-
Hungsten halogen lamp

yes

100% - 0%

Phase-lead, potentiometer
Phase-lead, potentiometer

Conv. transformer
Electronic transfomer


Low-pressure lamps

Lamp

Dimmable

Range

Technique

Notes

Fluorescent lamp

yes

100% - 0%
100 % - 1%

Phase-lead,
wattless control

Conv. ballast
electronic ballast

Compact fluorescent-
lamp (4-pin base only)

yes

100% - 0%
100% - 10%

Phase-lead,
wattless control


electronic ballast

Low-pressure-
sodium lamp

no

 

Only suitable for full-load operations

  


High-pressure lamps

Lamp

Dimmable

Range

Technique

Notes

High-pressure-
sodium lamp

partly

100% - 30%

Phase-lead
amplitude regulation

%

Mercury vapour-
lamp

partly

100% - 30%

Phase-lead
amplitude regulation

%

Metal halide-
lamp

no

%

not recommended

%