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Specialized - Thyratron ·Thyratron

7981

Gas-filled grid-controlled thyratron for industrial switching, controlled rectification, relay, motor-control, or pulse service.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
2.5 V / 13.5 A

Description

The Mullard 7981 is a high-current inert-gas thyratron designed primarily for motor-control switching.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

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

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

Thyratron

X-ray radiationInterelectrode capacitances
Max plate voltage
1500 V
Max cathode current
3.2 A

High-current motor-control thyratron.

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

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Thyratron

Characteristics

  • Filament Voltage Nominal

    2.5 V

  • Filament Current

    13.5 A

    At2.5V

  • Cathode Heating Time

    60 s

  • Anode-Grid Capacitance

    7.5 pF

  • Grid-Cathode Capacitance

    5 pF

  • Anode Voltage Drop

    16 V

    Approximate

  • Ionisation Time

    10 us

    Approximate

Other

  • Maximum Peak Forward Anode Voltage

    1500 V

  • Maximum Peak Inverse Anode Voltage

    1500 V

  • Maximum Peak Cathode Current

    40 A

  • Maximum Average Cathode Current

    3.2 A

  • Maximum Surge Cathode Current

    560 A

    Duration<=0.1s

  • Maximum Negative Grid Voltage Before Conduction

    250 V

  • Maximum Positive Grid Current Peak

    2.5 A

    AnodeVoltage>-10V