ITT - Index of

ITT
SELENIUM TRANSIENT VOLTAGE SUPPRESSORS
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SEMICONDUCTORS
TRANSIENT VOLTAGE
SUPPRESSOR RECTIFIERS
• AC Input or DC Applications
• Improve Equipment Reliability
• Reduce Equipment Cost
ITT transient voltage suppressors eliminate one of the major causes of
failure of semiconductor rectifiers by instantaneously short-circuiting
transient voltages in excess of the ratings of the rectifiers. They permit
the circuit designer to use rectifiers with lower PIV ratings, thereby reducing
equipment cost. These specially processed selenium cells have
very sharp "zener" breakdown characteristics when operated in the
reverse direction. Since the reverse characteristic is used instead of the
forward characteristic, aging has very little effect on the resistance and
suppressing voltage level of the protector. The small effects of aging and
temperature variations have been taken into consideration in the voltampere
curves and tabulated characteristics.
In inductive circuits using mechanical switches, these suppressors can
be used to eliminate pitting of the switch contacts by absorbing the high
peak voltages generated when the switch is opened. ITT contact protector
selenium rectifiers can also be used in this application.
Transient voltage suppressors can be mounted by eyelets or studs in
stack types and by clips or pigtail leads in tubular types. Stack types are
supplied with a standard industrial finish or with a moisture resistant
finish for protection against salt spray and humidity.
DIMENSIONS
PAPER TUBE TYPE
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2'~~""",, '*""~ .... '/)2
PHENOLIC TUBE TYPE
EYELET TYPE
RATINGS
STUD TYPE
CHARACTERISTICS 8A SERIES 25A SERIES 102 SERIES UNITS
Steady State RMS Volts/Cell 30 30 25 Volts
Peak Volts/Cell 42.4 42.4 35 Volts
DC Volts/Cell 20 20 20 Volts
Stack RMS Volts 30-600 36-600 25-500 Volts
Stack DC Volts 20-400 20-400 20-320 Volts
Steady State Leakage Current
(max.)
0.8 1.2 12 mA
Single Pulse Current
(4 milliseconds) (max.)
0.75 2 8 Amps
Recurrent Pulse Current
(1 millisecond @ 60 cps) (max.)
0.25 0.75 3 Amps
Ambient Temperature -20 to +100 -20 to +100 -20 to +100 °C
Cell Operating Temperature (max.) 130 130 130 °C
Construction Tubular Tubular Stud Or Eyelet
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