General
The first HF ballast came onto the market in
the mid-80s. At first the price was relatively high and the benefits
were low. Prices and quality have now stabilised at a more acceptable
level. Most people who choose luminares with HF ballast do so to reduce
running costs. The user-benefits of this are a reduced number of light
replacements and reduced running costs. Research has shown that lighting
using HF ballast causes less tiredness and better concentration. A
simple and cheap way to improve the interior environment would be to
install new luminaires with HF ballast.
We only use ballasts from
Europe’s most respected suppliers. All of our HF ballasts have inbuilt
innovations, such as warm start and constant light, independent of mains
supply.
Description of functions a HF ballast consists of:
Mains filter
Prevents the mains supply from damaging the ballast and any disturbances in the ballast reaching the mains supply.
Rectifier
Converts AC to DC power.
High frequency generator
Transforms the DC to a high frequency lamp current.
Control circuits
Logic
circuits that control, among other things, correct start-up and also
deactivation of failed tubes. Compared to conventional ballasts the
start-up is completed by the ballast itself. First, the cathodes are
pre-heated to the right temperature. This takes approx. 1 - 2 seconds,
then the starting pulse begins the charging process. It is the
high-frequency lamp current, which makes the light tube more efficient.
The thin fluorescent layer inside the tube makes the light constant and
not fluctuate with the mains frequency. This makes the light even more
efficient.
Flicker free
Conventional control
gear gives a light that fluctuates in tune with the mains supply. The
light flickers, and in some cases this can cause headache and
concentration problems. Using a HF ballast gives the tubes a higher
operational frequency (approx. 40kHz) and the result is a flicker free
light. See figure.
Rapid-start
Conventional
control gear with a starter will continue trying to restart the light
tube if it fails to start the first time. HF control gear provides a
one-time controlled start for the light tube.
Warm-start
Using
warm start, the cathodes are preheated prior to the actual starting
process. This reduces stresses on the emission materials, which emit
electrons, resulting in a longer lifecycle of the light tube.
Constant light
Constant
light means that the HF control gear gives a constant light current to
the light tube independent of mains voltage. This means that the light
tube gives a constant light level despite irregularities in the network.
Deactivated tubes
Conventional
control gear will repeatedly try to start defect lamp/s causing
flickering light tubes. After a time the starter will lock and leave the
lamps glowing.A rapid rise in temperature occurs, which in some cases
can be a fire risk ! Using a HF ballast, lamps that can’t be started
will be automatically deactivated. Note! In a two lamp ballast both
tubes will be disconnected even if only one of them stops working.
Mains supply
HF
ballast works with a mains supply of 230V +/-10%. It can have a
frequency of between 50 and 60Hz. Most also function with a DC power
source. Contact us for further information.
Leak current
The
network fi lter in the HF always contains a capacitor connected between
phase and ground. This results in a minor but constant leak current in
the luminaires. The luminaire standard limits this to 1mA, and this
should be used as a rule of thumb when you plan to scale the number or
luminaires on an earth circuit breaker. Note! Remember the max. values
for an earthed circuit breaker.