Guides

Dimmering of transformers

Product for dimmering transformers for lighting purposes consists of a multitude of types and manufactures. Dimmers can according to their methods of working be divided into different types such as inductive or resistive dimmers, tyristor-, triac-, or transistordimmer, leading-end or trailing-end dimmer.

A wrong choice of dimmer to a given transformer or a wrong choice of transformer to a given dimmer leads to a poor result and can cause heavy heat development in the transformer. In other cases the outcome will be that the lamps are flickering at low, medium or full load and the transformer will hum. Even if you manage to make the the right combination so that the dimmering characteristics are good this can be at the cost of the EMC-qualities in the finished installation. It can also occur that the deployment of a dimmer will prevent the normal protection functions of the transformers to work properly. The guide below does not assume to be complete and exhaustive and serves only to give certain general guidelines for dimmering of transformers for lighting purposes. We accept with gratitude information and experiences which will help us keep this information accurate, up-to date and reliable.

Types of dimmers

Dimmers used for dimmering of transformers are usually divided into

  1. Triacdimmer (controlled by a diac-diod) working according to front end phase-cutting of the sinuswave

    Properties:
    + ease of control
    + inexpensive
    - higher noise level. Ought to be placed so that the noise will not be disturbing, e.g. not on a large surface which may vibrate.

  2. Tyristordimmer (controlled by diac-diodes) regulating the sinuswave front end.

    Properties:
    + low noise level
    - more expensive than triacdimmers

  3. Transistordimmer often called dimmer for electronic transformers and mainly used for this purpose and for regulation of incandescent light. Cuts the sinuswave rear-end.

  4. Vrid transformer working according to the principle of changing the primary and secondary turnover ratio.

    Properties:
    + complete sinuswave (no interference impulses)
    + completely quiet
    - no ease of control

Which type of dimmer will fit which type of transfoemer

Dimmertype Transformertype
Triac Conventional inductive transformers with laminated EI-core or toroid
Tyristor Conventional inductive transformers with laminated EI-core or toroid
Transistor Electronic transformers
Induktiv Conventional inductive transformers with laminated EI-core or toroid

Please observe that there are exceptions, for instance Osram has an electronic transformer which requires dimmering with a tyristordimmer

For more detailed information you are welcome to contact us about dimmering. If you have information you want to share with us please contact us.