High Risetime Choke; Rack Control; Dimmer Profile; Response Speed - ETC SMARTRACK User Manual

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2.3.2 High risetime choke

The High Risetime choke is wound on a 4" toroidal iron powder core, and

produces a risetime in excess of 400µS. This is a requirement of the

Nordic Television Authorities for 2.5kW dimmers, and complies with the

BBC PID171 standard for 5kW and 10kW dimmers. It is recommended

for front of house lighting circuits in theatres and in concert halls, where

acoustic requirements may be critical.

Smartracks receive USITT DMX512/1990 dimmer drive signals from a very wide

range of lighting controllers, including all ETC Expression, Impression, Insight,

MicroVision, Connection and Reflection systems.

The control panel on each Smartrack enables the user to set and display a start

address for the rack, as well as to select, for each or all dimmers:

Any dimmer may be set to any one of 12 preprogrammed curves, includ-

ing three non-dims and a 'hot' setting (permanently on). This should take

care of the requirements of the vast majority of entertainment and architec-

tural applications, and custom profiles may be generated if required.

A dimmer's response speed is the time it takes for the dimmer's output to

arrive at a new level, following the reception of a new level instruction by

the dimmer's control electronics, and is measured in milliseconds. Don't

confuse response speed (in milliseconds) with risetime (in microseconds).

Smartrack ships with a default 100mS response speed set for all dimmers,

but allows the user the choice, for any or all dimmers in a rack, of 30,

100, 300 or 500mS.

Thus, a studio with RCDs and a lot of 5kW loads might function happily

with all dimmers set to 300mS response time, while individual circuits for

Smartrack User Manual

page 5

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