Applications
 Sensor lines
 Control lines
 RS-232 lines

Features
 Three stage protection
 Superior to diode or TVS only based designs
 Screw terminal blocks
 Industrial grade weatherproof die cast
aluminum enclosure with mounting
brackets

Description
The ALW-D2-12 is HyperLink’s outdoor version of its HGLN-D2-12 protector. This high
performance 3-stage lightning protector provides superior protection of differential or
balanced digital or analog lines from transients and surges. The units will protect two pairs
of differential data or analog signal/control lines.
The first stage is comprised of a differential gas discharge tube. Stage two is a pair of
current limiting series resistors and the final stage is a low capacitance diode array. The
use of three terminal differential gas discharge tubes provides superior common and
differential mode protection against conducted transients versus the use of lower cost two
terminal tubes. The second stage series resistance limits the power dissipation of the fast
diode clamp array in the third stage. This allows time for the slower but higher power gas tubes to flash over. The diode array
clamps the leading edge of fast transients to safe levels until the high power gas tubes turn on. This eliminates the damaging
leading edge spike that single stage gas tube protectors let leak through. The diode array’s low capacitance assures that the
suppressor will not degrade the high-speed signals. The 3-stage design can handle higher-level transients than a protector that
uses only diodes.
For more complete surge protection of data lines, the use of two units is recommended, one at
each end of the line.
Industrial Grade Weatherproof Enclosure
This protector features an industrial grade die cast aluminum enclosure with gasketed cover
and concealed mounting holes. It includes an aluminum mounting kit and hardware. PG16
cable glands are provided on the enclosure as well as an external ground clamp to provide a
tie point for earth ground.