ProSoundWeb Community

Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => Lighting FUD Forum Archive => Topic started by: Ron Wilson on November 11, 2008, 12:02:39 PM

Title: Toroidal filtering
Post by: Ron Wilson on November 11, 2008, 12:02:39 PM
NSI describes their dimmer as being "Dual SCR Circuit Design, Toroidal filtering". Is this a advantage over other brands I.E
less noise in sound systems, all things being equal?
Title: Re: Toroidal filtering
Post by: Rob Timmerman on November 11, 2008, 07:06:24 PM
Dual SCR design is what's been used in professional grade dimming for decades (the cheaper, low end option being Triacs, and the current SoTA being IGBT).

Toroidal filtering means that they put a (probably small) choke in series with the output of the dimmer circuit to get rid of some of the switching noise.  Again, this has been standard practice since the early days of electronic dimming.  The question is not if there is an output filter, but instead, how big is it (what's the rise time of the waveform)?  Minimal filtering will get a 350ms rise time, while better filtering will get a 500ms or 800ms rise time.

Both of those "features" are standard design practice in professional-grade dimmers