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Specialized - Thyratron ·Triode

NL760

Quick-heating industrial gas-and-mercury thyratron for welding control, motor-speed control, and regulated rectifiers. Its massive cathode supports heavy switching.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
DOWN
Socket code
SJ4
Base pins
-
Nominal heater
2.5 V / 21 A

Description

NATIONAL POWER TUBE NL-760 is a quick heating industrial thyratron designed especially for weld- ing control, motor speed control, and regulated rectifier applications. It is gas and mercury filled for quick starting, constancy of characteristics within wide temperature limits, and long life. NL-761 has the same general characteristics, within its narrower temperature limits, but is filled with mercury only to permit use of the tube at higher voltages. Both types are available with bracket type bases for panel mo

Socket description

Super-jumbo 4-contact bayonet

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
DOWN
Socket code
SJ4
Base pins
-
Nominal heater voltage
2.5 V
Nominal heater current
21 A
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

DOWN - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Max plate voltage
1500 V
Max cathode current
6.4 A
Rectifier peak inverse voltage
1500 V
Rectifier nominal output current
6.4 A
Rectifier peak forward current
77 A
Rectifier warm-up time
60 s

Published ratings and characteristics promoted where canonical fields apply.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1956 National Electronics Industrial Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • NL-760 &

    NL-761

    Source technical-information table; wording preserved from datasheet.

  • 6.4 Amperes do

    77 Amperes Peak A

    Source technical-information table; wording preserved from datasheet.

  • NL-760

    NL-761

    Source technical-information table; wording preserved from datasheet.

  • do Amperes output (Maximum)

    6.4 | 6.4 | 4.0 A

    Source technical-information table; wording preserved from datasheet.

  • Instantaneous Amperes Output (Maximum)

    77 | 77 | 30 A

    Source technical-information table; wording preserved from datasheet.

  • Maximum time of averaging anode current (seconds)

    15 | 15 | 15 A

    Source technical-information table; wording preserved from datasheet.

  • Maximum peak inverse volts

    1500 | 1500 | 5000 V

    Source technical-information table; wording preserved from datasheet.

  • Maximum peak forward volts

    1500 | 1500 | 2500 V

    Source technical-information table; wording preserved from datasheet.

  • Condensed mercury temperature limits (°C)

    —40 to +80* | +40 to +90 | +40 to +65 C

    Source technical-information table; wording preserved from datasheet.

  • Filament volts

    2.5 V

    Source technical-information table; wording preserved from datasheet.

  • Filament amperes

    21 ± 2 A

    Source technical-information table; wording preserved from datasheet.

  • Filament heating time (seconds)

    60 | GRID CHARACTERISTIC s

    Source technical-information table; wording preserved from datasheet.

  • Maximum negative grid voltage before conduction (volts)

    500 V

    Source technical-information table; wording preserved from datasheet.

  • Maximum negative grid voltage during conduction (volts)

    10 V

    Source technical-information table; wording preserved from datasheet.

  • Maximum critical grid current (mcroamps)

    10 A

    Source technical-information table; wording preserved from datasheet.

  • Maximum ac short circuit current (amperes)

    770 A

    Source technical-information table; wording preserved from datasheet.

  • Approx. temp. rise, cond. mercury above ambient (°C)

    30

    Source technical-information table; wording preserved from datasheet.

  • Net weight (ounces)

    9 oz

    Source technical-information table; wording preserved from datasheet.

  • Approx. shipping weight (lbs.)

    5 lb

    Source technical-information table; wording preserved from datasheet.

  • between —40 and

    +80°C. For maximum life the condensed mer-

    Source technical-information table; wording preserved from datasheet.

  • cury temperature after warm-up should run between

    +40 and C

    Source technical-information table; wording preserved from datasheet.

  • +80°C which corresponds to approximately

    +10 to +50°C ambient

    Source technical-information table; wording preserved from datasheet.

  • 0.566'DIAM

    CAP CI-5 | .66! DIA. CAP

    Source technical-information table; wording preserved from datasheet.

  • CAP CI

    -5 ANODE ~ CI —S

    Source technical-information table; wording preserved from datasheet.

  • NL-760P

    NL-76 0L

    Source technical-information table; wording preserved from datasheet.

  • NL-760

    e G7 . NL-761 L

    Source technical-information table; wording preserved from datasheet.

  • NL-76I

    NL-761P | MAX

    Source technical-information table; wording preserved from datasheet.

  • 8: MAX

    • | 2 fI

    Source technical-information table; wording preserved from datasheet.

  • ~— INDUSTRIAL

    !1

    Source technical-information table; wording preserved from datasheet.

  • Printed in U.S.A

    12%56 G.R.

    Source technical-information table; wording preserved from datasheet.

Characteristic

  • Typical arc drop at 20 amperes peak (volts)

    12 V

    Source technical-information table; wording preserved from datasheet.

  • Ionization time (approx., microseconds)

    10 | 4 us

    Source technical-information table; wording preserved from datasheet.

  • Deionization time (approx., microseconds)

    1000 | s us

    Source technical-information table; wording preserved from datasheet.

  • Anode to grid capacitance (uuf)

    4 pF

    Source technical-information table; wording preserved from datasheet.

Data set 02

1957 National Electronics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum peak forward voltage

    1500 V

  • Maximum peak output current

    77 A

  • Maximum dc output current

    6.4 A