Digital Dimming Explained - ETC SMARTRACK User Manual

smartrack
U M
SER ANUAL

1. Digital dimming explained

There are good reasons why users of professional dimming equipment are now only
willing to accept true digital dimming equipment, such as ETC Smartrack and
Smartpack. They are:
Accuracy – digital dimmers are able to regulate output levels to reproduce precisely
recorded intensities, even when mains power is fluctuating.
Reliability – with fewer electronic components, digital dimmers literally have less
things to go wrong.
Smarts – with processing power on board, digital dimmers can perform tasks previ-
ously impossible with analogue techniques. These include diagnostic functions, indi-
vidual dimmer profile and response speed settings, and more.
Cost – a well designed digital dimmer typically uses fewer electronic components
and is therefore cheaper to manufacture.
The key to the accuracy of digital dimmers is regulation. This means that the dimmer is
constantly measuring the rms voltage of each supply phase (a total of 12,800 times per
second in the case of ETC Smartrack) to build up an accurate picture of the condition of
the mains supply to each dimmer. Using this information, the power devices are pre-
cisely controlled, to compensate for any mains voltage fluctuations and produce a con-
stant voltage output for any given control level.
Of course, in an age where virtually all lighting control consoles output the same inter-
nationally accepted digital control signal (USITT DMX512), another plus with digital
dimmers is that no expensive demultiplexer stage is required. The digital signals from
the lighting console are simply connected directly to the dimmers.
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