(Quick
Question Form)
Most
surge suppressor manufacturers make grand claims about their
products but publish little of the technology involved.
We claim that our Brick Wall
surge filters offer performance, reliability and safety advantages
that are unparalleled by other surge protection products. The
following represent the basic engineering principles.
External surges first encounter
the Series Mode surge reactor L1, and must pass through this
reactor to reach the protected equipment. L1 resists the surge
frequencies and immediately (zero response time) provides current
limiting. The surge reactor behaves like a relatively high value
resistor at the surge frequencies and dissipates some of the surge
as heat. Unlike MOVs, TRANS-ZORBS and similar shunt elements
that weigh less than 1/4 ounce, the Brick Wall surge reactor can
easily absorb any surge repeatedly with absolutely no degradation.
The surge reactor in conjunction
with the capacitor C2, restricts the incoming voltage slew
rate of up to 5,000 volts per microsecond to a maximum of 100
volts per microsecond (1 volt per 10ns). L1 and C2 operate
continuously and react instantly for surges or noise lying within
the normal dynamic range of the power wave. If the surge exceeds
the normal 180 volt peak dynamic range of the power wave, the dynamic
clamp circuit (D1 C3) which tracks the peak of the power wave
comes into play. With a diode clamp response time of 5ns, and
maximum slew rate limited by L1 and C2 to 1 volt per 10ns, even a
worst case surge will be clamped by the time the voltage exceeds
the clamp voltage by 1 volt. The clamp circuit places a 180f
capacitor (C3) in parallel with C2, reducing the surge slew rate
to about 8 volts per microsecond.
Two 'crowbar' circuits act on
high energy surges. The series connected crowbar circuits consist
of a SCR switch, inductor and a 180f capacitor, chosen to minimize
the disturbance on the power wave. The first crowbar
circuit responds to the slew rate of the incoming surge. If a
surge is large enough to generate more than 30 volts in less then
2s across C3, then the slew rate crowbar neutralizes the surge.
Should C4 become charged, and the voltage again begins to rise, a
second crowbar will activate at 220 volts peak to provide a final
measure of protection.
Since the surge reactor is a high
impedance at the high frequencies of the surge, minimal high
frequency current flows in the neutral wire and consequently the
'common mode' problem created by simple shunt suppressors does
not exist with Brick Wall products.
Our engineering staff is always
available to answer any technical questions you may have. Computer
simulations and custom configurations can be provided.
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