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NL643

Directly heated mercury-filled industrial rectifier for power applications up to approximately 200 V DC. Rated for approximately 700 V peak inverse voltage and 15 A nominal output.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: DOWN
Socket code: -
Base pins: -
Nominal heater: 2.5 V / 20 A

Description

NATIONAL POWER TUBE NL-643 is a sturdy rectifier tube designed especially for industrial power rectifier applications up to 200 volts dc. It is mercury filled for efficiency and the ability to withstand high inverse voltage. NL-643 is designed to give exceptionally long life when used within its ratings. NL-643 RECTIFIER TUBE TECHNICAL INFORMATION do Amperes output (maximum) 15 Instantaneous Amperes output (maximum) 90 Maximum time of averaging anode current (seconds) 15 Maximum pea

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: DOWN
Socket code: -
Base pins: -
Nominal heater voltage: 2.5 V
Nominal heater current: 20 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

Rectifier

X-ray radiationInterelectrode capacitances

Max cathode current: 15 A
Rectifier peak inverse voltage: 700 V
Rectifier nominal output current: 15 A
Rectifier peak forward current: 45 A
Rectifier forward voltage drop: 10 V
Rectifier warm-up time: 120 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

Rectifier

Other

rectifier applications up to
200 volts dc. It is mercury filled for efficiency and the ability to withstand
Source technical-information table; wording preserved from datasheet.
do Amperes output (maximum)
15 A
Source technical-information table; wording preserved from datasheet.
Instantaneous Amperes output (maximum)
90 A
Source technical-information table; wording preserved from datasheet.
Maximum time of averaging anode current (seconds)
15 A
Source technical-information table; wording preserved from datasheet.
Maximum peak inverse volts
700 V
Source technical-information table; wording preserved from datasheet.
Filament volts
2.5 V
Source technical-information table; wording preserved from datasheet.
Filament amperes
23 + 2 A
Source technical-information table; wording preserved from datasheet.
Filament heating time (seconds)
120 s
Source technical-information table; wording preserved from datasheet.
Maximum ac short circuit current (amperes)
750 A
Source technical-information table; wording preserved from datasheet.
Condensed mercury temperature limits (°C) (700 volts peak inverse)
+ 35 to + 90 V
Source technical-information table; wording preserved from datasheet.
Condensed mercury temperature limits (°C) (500 volts peak inverse)
+ 35 to + 100 V
Source technical-information table; wording preserved from datasheet.
Approximate temperature rise, cond. mercury above ambient, no load (°C)
35 C
Source technical-information table; wording preserved from datasheet.
Approximate temperature rise, cond. mercury above ambient, full load (°C)
50 C
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.

Characteristic

Typical arc drop at 45 amperes peak (volts)
10 V
Source technical-information table; wording preserved from datasheet.
Typical Anode starting voltage (volts)
13 V
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

Rectifier

Other

Maximum DC output current
15 A
Maximum instantaneous output current
45 A
Maximum peak inverse voltage
700 V

Characteristic

Filament heating time
120 s
Typical arc drop
10 V
Typical anode starting voltage
13 V

Construction

Filling
Mercury vapor

Application

Service
Industrial power rectifier