Western electric 346 c brochure

Page 1

BELL SYSTEM PRACTICES A846. 346C
Transmission Engineering and Data Issue 1, January 1962
Electron Tube Data A.T.& T. Co. Standard

ELECTRON TUBE DATA SHEET
WESTERN ELECTRIC 346C ELECTRON TUBE

DESCRIPTION

The 346C is a three-electrode, inert-gas-filled, cold cathode tube for use in
relay, voltage regulator, or rectifier circuits. This tube is especially suitable
for use in control circuits such as in triggering, counting, or switching apparatus.

CHARACTERISTICS

Peak Anode Voltage - - - » - - - - - ' - ' - - - - - - 225 v0its
Average Cathode Current - - ~ - - - ~ ' ' - - . - - ' 10 100 milliamperes
Average Life, Approximate ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 10000 10 hours

File: Cold Cathode Section

© American Telephone and Telegraph Company 1962 3460

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346C ~PAGE 2

MAXIMUM RATINGS, Absolute System(N0te D

Forward Peak Anode Voltage . . ~ - - - . - - - - . - - - - - - 225 volts
Forward Cathode Current(Note2)

Peak . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 milliamperes
Average . . . . . . . . . . . . . . . . . . . . . . . . . . 35 milliamperes
Averaging Time . . . . . . . . . . . . . . . . . . . 2 seconds
Inverse Peak Anode Current (Note 2) . . . - . ~ - - - - - - - 5 milliamperes
Ambient Temperature Limits- - - - - - - - - - - - - - - - - -55 to +85 centigrade

ELECTRICAL DATA, Throughout Life
Min. Bogey Max.

Starter Breakdown Voltage (Note 3). - . . - - . . - - - 65 70 89 volts
Starter Voltage Drop at 20 milliamperes. . . . . . . . 52 60 74 volts
Anode Voltage Drop at 20 milliamperes. . . . . . . . . 72 80 90 volts
Transfer Current . - - . . . . - . . . . . . . . .See curve - Fig. 3

Ionization Time - Starter Gap Deionization Time, Approximate

Starter Gap . . . . . . . . . . . . . . . . . . . . . - 2 - milliseconds
Main Gap . - - . - - . - - - - - - - - - - . - - - - - 8 - milliseconds
Inverse Current at -120 Volts Anode Potential(Note 5). - - 3 milliamperes
MECHANICAL DATA

Mounting Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Any

Net Weight, Approximate . . . . . 1 Ounce

Dimensions and pin connections shown in outline drawing on page 4.
HANDLING

This tube contains a small amount of krypton-85 gas which is a by-product
radioactive material. The amount of krypton-85 is less than five microcuries, which
is too small an amount to require any special care in use.

Atomic Energy Commission regulations require that the individual tube carton
for tubes containing by-product radioactive material be appropriately marked. The
marking includes the statement that tube disposal should be in approved manner.

Approved instructions for disposal of tubes containing krypton-85 are as
follows;

Tubes to be disposed of should be broken or crushed in a well
ventilated place releasing any resulting vapors to the outside
atmosphere. The residual broken or crushed tubes should be dis-
posed of in a normal public trash disposal system. Tubes should be
disposed of at a rate of not more than 100 each week from any one
location. Avoid breathing vapors from broken tubes.

Note 1: In the Absolute System" the maximum ratings specified are limiting values above which the
serviceability of the device may be impaired from the viewpoint of life and satisfactory
performance. Maximum ratings, as such. do not constitute a set of operating conditions and
all values may not, therefore, be attained simultaneously.

Note 2: Sufficient resistance must be used in series with the tube to assure that the electrode
currents do not exceed their maximum rated values.

Note 3: Limits apply immediately after tube has conducted current. If the tube has been idle. these
values initially may be as much as 3 volts higher or lower.