Clipsal C-Bus and standalone dimmers when used with Electronic

Transformers
There are two different types of transformer technologies used when installing safe extra low voltage (12V) tungsten halogen lighting, i.e. wire wound transformers and electronic transformers.

Wire-wound Transformers
These transformers are also known as “ferro-magnetic” or “iron-core” transformers. They are constructed from copper wire wrapped around an iron core and have been used in the electrical industry for many years. They are generally suitable for dimming applications when used in conjunction with dimmers which use ‘Leading Edge’ phase angle control.

Electronic Transformers
In the last few years the use of electronic transformers in conjunction with 12V tungsten halogen lighting has become popular. Electronic transformers are generally more suited for
dimming applications when used with dimmers which use ‘Trailing Edge’ phase angle control.
However, some electronic transformers can be used with Leading Edge type dimmers, usually with an appropriate de-rating of the dimmer.

Electronic Transformers – Compatibility with Clipsal Leading Edge Dimmers
Clipsal have tested various manufacturers’ electronic transformers to establish their compatibility with Clipsal leading edge dimmers and have historically published a list of ‘compatible electronic transformers’.

As a result of the large number of electronic transformer models that are now available on the market and the on-going changes in product specifications made by manufacturers of electronic transformers, Clipsal are no longer able to provide this service effectively. Please contact the electronic transformer manufacturer (or distributor) to establish the
preferred dimming method of a particular electronic transformer (i.e., leading edge or trailing edge). When this is know, a suitable Clipsal dimmer can be sourced and used in conjunction with the transformer.

Alternatively, the method described below can be used to estimate the maximum number of specific electronic transformers that can be connected to a Clipsal Leading Edge dimmer.

Estimating the maximum number of trailing edge electronic transformers that can be connected to a Clipsal Leading Edge dimmer
A limited number of trailing edge electronic transformers can generally be connected to a Clipsal Leading Edge dimmer, with appropriate de-rating of the dimmer. The quantity of
transformers which can be connected to a dimmer varies and is dependant on the "input capacitance" of a specific transformer. This input capacitance value can be obtained from the
electronic transformer manufacturer (or distributor).