POWER LINE FILTERING
SYSTEM NOISE
Electronic noise is undesirable low level high frequency signals found on the powerlines and/or datalines. It is often the cause of scrambled data, slow data transfer, mis-operations and lock-ups. Its long term cumulative effect can eventually cause hardware failure. Series Mode is a power filter technology; it provides exceptional powerline filtering.
POWERLINE FILTERING
Powerline noise first encounters a series inductor (choke). The inductor will act as an open circuit to higher frequencies and a short circuit to lower frequencies. The higher frequencies that do leak through then encounter a series of dynamically inserted capacitors. Here the opposite takes place. The capacitors act as short circuits to higher frequencies and as open circuits to lower frequencies. The capacitors will return the noise and any surge current slowly (harmlessly) to the neutral. The dual filtering aspect of a Brick Wall Surge Filter makes for superb powerline filtering characteristics, even in non-surge applications.
FULLTIME POWERLINE FILTERING
Being a passive component, the series inductor is always operational. A 2µf capacitor is also always active. Attenuation: 3db @ 3kHz, 38db @ 100kHz, >50db @ 300 kHz.
POWERLINE FILTERING UNDER A SURGE CONDITION
In a powerline surge situation up to three additional dynamically inserted 180µf electrolytic capacitors come on line(Figure 2). A Brick Wall surge filter will interpret any two volt rise above the peak of the sinewave, regardless of powerline voltage, as a surge condition. A small powerline voltage fluctuation will activate this capacitor arrangement. Attenuation: 8db @ 100Hz, 28db @ 1kHZ, 46db @ 10kHz, >70db @ 100kHz (50 ohm).
The graph on the left indicates the filtering characteristics of Brick
Wall Surge Suppressors/ Powerline Filters. Line 1 represents the filtering
provided by a massive inductor in conjunction with a 2µf capacitor. This
attenuation is provided under normal operating conditions. The dynamic
clamping characteristics of the unit sees any 2 volt rise above the peak
of the sinewave as a surge condition. This will activate the first 180µf
electrolytic capacitor (Line2). If the surge energy continues to rise two
more electrolytics dynamically come on line (Lines 3 & 4) providing
even greater noise attenuation.
