New
Performance Standards
The following graphic represents a comparison of
standard oscilloscope traces. The MOV based protector (left) and a
Brick Wall Surge Filter (right) are both experiencing a 1200V,
450A surge.
INSTANTANEOUS
RESPONSE TIME
The heart of our units is the inductor. This is a passive
component that is in series. It does not
have to 'turn- on' and it represents the only path the surge
current can take to get to the load. It
reacts instantaneously. Almost all other surge protection devices
are in parallel. After a certain
voltage threshold is reached the shunt elements create a short
circuit diverting the surge current
away from the load. In effect it is a switching device. Any
switch, no matter how good, is going to
take time to go from an opened to a closed position.
CLAMPING LEVEL 2 VOLTS ABOVE THE SINEWAVE
PEAK
MOVs are preset to clamp at certain voltage thresholds (usually
around 220V). The manufacturers walk a fine line here because too
low a level and the MOV turns on more and wears out sooner. Too
high a level and more unwanted current has access to the load.
Even more importantly, marketing rhetoric is sacrificed. Our
Series Mode device has active tracking; a 180f electrolytic
capacitor constantly tracks the sinewave peak, whatever the
powerline voltage Any rise above this reference level is
immediately clamped to this level.
LET THROUGH VOLTAGE <400V
Voltage that gets by a surge suppression device to the load is
called the let through voltage. The
lower the let through voltage the better. The above oscilloscope
trace of a Brick Wall product
shows a let-through voltage of 192V for a 1200V transient. That
represents an additional 20V
above the sinewave peak (the sinewave peak is normally 172V).
When we had our products UL listed under UL 1449 Second Edition, the protocol
called for a let through voltage of less than 330V during a single surge of 6000V,
3000A. To take it a step further, we also had UL endurance test our surge protectors
with one thousand 6000V surges and the let through never exceeded 400V.
We believe
this represents the lowest let through voltage in the industry.
SLEW RATE
Slew Rate is the rate of change of voltage in volts per
microsecond. The faster the slew rate the
more readily the overvoltage will couple to nearby datalines.
Notice the ascending slew rates of
the photographed oscilloscope traces. This is representative of
the voltage that 'hits' the load
before clamping. A quick rise such as this can represent quite a
'jolt' to the equipment. The trace
of our unit shows a negligible slew rate. Again, we believe this
represents a new industry
standard.
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