This information is presented in the Bruck catalog.
A transformer is required to transform the mains voltage
(120V) to the low voltage (12V) that is required for
the operation of low voltage lamps. The transformer
may be wire-wound (magnetic) or electronic and both
types are available with various features that dictate
their application. Generally, electronic transformers
have a high frequency output, are small in physical
size and weight and often include features such as output
voltage regulation and dimming capability.
These transformers are typically limited to applications
where the connection to the LV lamp is less than 80"
in order not to exceed the International Standards for
This limitation means that electronic transformers
are typically used for small systems of up to 105W.
The output frequency of magnetic transformers is 60Hz
and can be used to feed LV lamps at distances of greater
than 80" without EMV problems.
This makes them particularly useful for lighting track
systems and for higher power output, typically up to
300W. The transformers need to be mounted close to the
track system in order to minimize the volt drop through
the power feed cable.
For this reason surface mounted and decorative remote
transformers are typical. Inductive transformers are
very reliable because the technology is very simple
All LV lamps can be dimmed to zero and all magnetic
transformers can be dimmed using dimmers designed for
The dimmer must be rated to at least the rating of
the transformer, e.g. 300W dimmer for 300W transformer.
Not all electronic transformers are dimmable and those
that are require dimmers designed for this purpose so
compatibility must be checked with the manufacturer.
LV Lighting System Loading
A 300W circuit can have a load of up to 6 x 50W lamps,
8 x 35W, 15 x 20W or combinations of different wattage
lamps, which give a combined wattage of 300W.
Fundamentals of lighting using low-voltage halogen
Bruck Lighting has long recognized the advantages of
low voltage, halogen, and incandescent lamps.
These advantages are mainly due to the small size of
the lamps. Compared to other light sources the filament
is shorter and has a larger cross sectional area, which
creates an almost dot shaped point of light.
The high luminous density of this point of light is
ideal for channelling and directing with reflectors
whose small size make them especially useful in display
and accent lighting applications.
Advantages in brief:
- Uniform white light throughout the whole service
- Excellent colour rendering, brilliant for fresh
- High efficiency, more usable light at the same wattage
and with long life - typically 4000 hours.
Note: All low voltage lamps distributed
by Bruck are low-pressure versions and may be used in
light fixtures without protective glass.
See Lamp Chart and Voltage Drop in
LV Lighting Systems at the bottom of the page.