Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
AUTOMATIC CURRENT REGULATOR
INTRODUCTION
The Amperite automatic current regulator is a reliable current regulating device, which
can maintain a constant current in a circuit over a very wide range of input voltages. It
consists of a resistance wire with a positive temperature coefficient of resistance,
hermetically sealed in a bulb containing hydrogen or helium gas. The resistance of this
element will automatically increase or decrease in accordance with the change of
temperature in the unit to maintain a very accurate current level. The circuit of Figure 1
shows how an Amperite current regulator is connected to the load.
Figure 1 - Connecting the Amperite Regulator
Figure 1a - Typical Voltage/Current Relationship of Ballast (No. 2HTF7)
Figure 1A is an illustration of a typical input voltage/current relationship of the current
regulator. Note the extremely accurate current level over the wide range of input voltage,
6 to 20 volts in this case. Ballast regulators are designed to maintain a constant current
with great efficiency, usually within + or -1%. Referring to Figure 1A, the most accurate
current regulation will be obtained at the flat, mid-point section on the curve. As the
voltage operating levels move up and down the curve the current will vary to some
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
degree. Being a constant current device the current regulator can be used only to regulate
a constant load - fixed wattage.
The Amperite current regulator is always connected in series with the load. The type
number would depend upon the current requirement of the load. In addition, Amperite
regulators can be connected in parallel with each other to handle any amount of current.
The Amperite voltage regulator will maintain both voltage and current regulation
simultaneously when connected in series with the load; however, current regulators
should never be connected in parallel with the load.
HISTORY-PROVEN & RELIABLE
Amperite ballast regulators have been used successfully in countless control applications
for over 79 years. Amperite provided current regulation for the early DC radio sets, and
then were used for voltage regulation in generations of AC radios and equipment. Today,
new Amperite current regulators are specified as current controllers in jet engines,
regulators in air conditioning and scientific/industrial equipment and are used in precision
instrumentation, communications equipment and military applications.
CURRENT REGULATING RANGES
Most ballast tubes manufactured have been designed for specific applications over
current ranges of 50 milliamperes to 6 amperes, and voltage ranges of 3.0 to 70 volts.
Although any number of tubes may be connected in parallel to attain any desired current,
it is possible that a unit, which will meet your requirements, has already been
manufactured. Amperite ballast tubes are manufactured to meet military specification
MIL-R-3080B. Please contact factory for specific requirements on your application.
CAPACITIES AVAILABLE:
Current values of 60 ma. to 5 amps.
Threshold voltage (see Fig. 2) 0.4 to 40 V
Figure 2 - Characteristic curve of a typical Amperite. Approximate curve of any other Amperite
can be obtained by multiplying or dividing the current of voltage scale by any number.
Max. Dissipation per Amperite 40 W per tube (T-12 Bulb)
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
Amperite can be used on AC, DC, or pulsating current.
Ballast tubes should not be operated in series.
Any number of Amperites with the same voltage range can be operated in parallel.
BASES AVAILABLE AND BASE WIRING
Radio octal 8-pin, 9-pin miniature standard wiring prongs 2-7.
4 Prong Radio - for current over 3 amps. - wiring FF.
GENERAL ADVANTAGES
… Light, compact… No moving parts
… Rugged, will stand vibration of 10G minimum
… Hermetically sealed; not affected by altitude or humidity changes
… Can be changed as easily as a radio tube
… Operates equally well on A.C. or D.C.
AMBIENT EFFECTS:
Ambient temperature variation of -50 degrees to +70 degrees C - will change the current
value of ballast regulating tubes approximately 2% on regulating portion of curve. Being
hermetically sealed the Amperite is not affected by altitude or humidity changes.
TIME LAG CHARACTERISTICS:
Time lag encountered in an Amperite Ballast Tube depends upon the wattage consumed
by the ballast and the size of the bulb. Where the wattage is small for the size of the bulb,
the action can be made practically instantaneous - less than 1 second. In such cases the
bulb will remain at practically ambient temperature. When the wattage is high enough to
heat the bulb to a temperature uncomfortable to the hand (160 degrees F) the lag might be
as much as several minutes for final readings - but normally reaches within 90% of final
readings within a few seconds.
LIFE EXPECTANCY:
Average life if operated as recommended 2000 hrs.
If operated continuously at maximum voltage 1000 hrs.
If operated continuously at 80% maximum voltage 5000 hrs.
If filament is operated below glow point 5000 hrs. and up
In operation, the Amperite filament starts to glow at one point; as the voltage is
increased, the glow spreads over the entire filament. Like incandescent lamps, turning the
ballast tube on and off reduces its life, especially if operating near its maximum voltage.
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
RESISTOR CURRENT REGULATOR (BALLAST) PART NUMBERS STILL
AVAILABLE:
1-1 2-20-30 3TF3B 6H-16 D9T1
1-15 20-1H 3TF4 6H-4 EW23B
1-16 20-3 3TF4A 6H-6 F4120A
1-1E 20-4 3TF4B 6H10 GL522-B25
1-3 20A10 3TF7 6HTF4 GL5621/B6
1-30 21-2A 3TF7A 6T1H GL5624/B46
1-4 210511-A 3TF7B 6T4 K26J218
10-11 22-4 3TF7/H 6T4A KS14595
10-21 23-6 3TFB 6T4D KS16479
10-25 24-1H 3TFV4 6T4E KS19056
10-2A 24-6A 3TFV4B 6T4F L55B
10-3 26-4A 3TK2 6TF2 R1900
10-4 26T4A 3V4 6TF4 R2D4
10-40 27-7 3W5 6TF4A R3000
10-4A 2A10 4-12 6TF4B R3003A
10-4B 2A12 4-25 6TF7 TJ102L01
10-4C 2A20 4-8TF1 7-4 TJ311M01
10-4D 2A21 4-B 7-7 TJ601K01
10-4E 2B14 40-4 7-7A TJ791K01
10-4G 2H-4M 40-5 7-A W72-43
10-7 2H-8 40-6E 77-127 W72-69
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
10A10 2H10 41-2 77-128 WL-788
10A12 2H10R 41-7E 7A10 WL712
10A20 2H20 42-2H 7A10B
10T1 2H30 42-3 7A20
10TF2 2H4 43-4 7H-10
11-11 2HT7 46-2 7H-11
11-3 2HT7B 4A1 7H-12
11-4 2HTF11 4A10 7H-20
11A10 2HTF4 4A10S 7H-7B
12-11 2HTF7 4H-1 7H4
12-1H 2HTK2 4H-12 7H4B
12-2 2M2 4H-12A 7H7
12-2A 2R67 4H-25 7HTF2
12-3 2TF10 4H-30 7HTF3
12-3H 2TF11 4H10 7HTF3D
12-4 2TK7 4H11 7HTF4
120A 3-11 4H3 7TF4
121B 3-112 4H4C 7TF4A
12A10 3-11B 4H7 7TK3
12T1 3-14 4HM3 8-11
13-3H 3-14B 4HT1 8-3B
13-4 3-15 4HT11 8-4
13-7 3-16 4HTF11 8-4A
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
13A10 3-38 4HTF4 8-4D
14A10 3-38A 4HTF4A 8-7
14A20 3-38B 4HTF4B 8A10
14T1 3-4 4T2 8A10A
15-11 3-40 4T2B 8H-8H-3
15-2 3-4A 4TF4 8HTF3
15-4 3-4B 4TF7 8TF2
15A10 3-4D 5-11 8TF3
15A20 3-5 5-16 8TF4
15T1 3-50A 50-4 9-11
15TF2 3-7 5324-2 9-3
16-4 30-11 55-1 9-4
16A10 30-7 55-1H 9-4A
16N2 3008040B 55-4 9-4C
16T1 3014055A 5A10 9-4D
17-3 30R4 5A10S 9-6
17-7 31-4 5A20 9-7
17G2 33-11B 5H-10 9-7B
18-3 34-2 5H-11 9-8
18A10 35-4 5H-12 9A10
1A10 36-11 5H-3 9A22
1A20 37-4 5H-4 9H4
1F1 3A10 5H1 9H9
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
1H-10 3A10B 5HA20 9HTF1H
1H-11 3A20 5HT3 9TF2
1H-20 3F3B 5HT4 9TF4
1H-25A 3H-1-7 5HTF1 A19A
1H-46 3H-10 5HTF2 AP1260
1H-4B 3H-10B 5HTF4 D5TF10
1H-50 3H-11 5M1 D5TF30
1HM2B 3H-12 5T1A D6-10
1HM4 3H-20 5TF11 D6HT3
1HT11 3H-20B 5TF2 D6M1
1HT2 3H-25 5TF4 D6M2
1HT9K 3H-4 5TF40 D6M3
1HTF10 3H-4B 5TF4D D6T11
1HTF10A 3H-7 6-11 D6T1H
1HTF10B 3HTF11 6-11B D6T20
1HTF10C 3HTF4 6-12 D6T7
1HTF10D 3HTF4A 6-13 D6TF20
1HTF11 3HTF4B 6-13B D6TF30
1HTF11A 3HTF7 6-1H D6TF4
1HTF11B 3M2 6-3 D6TF9
1HTF11C 3M4 6-36 D6TK6
1HTF4 3T1 6-4 D6TK7
1HTK11 3T11 6-4A D7-20
Amperite Co.
567 52nd Street
P.O. Box 329
West New York, NJ 07093
(800) 752-2329
Solving your relay requirements since 1922 www.Amperite.com
1M2 3T2 6-4B D7H-6
1S10 3T4 6-4C D7H20
1TF10 3T4A 6-7 D7H4
1TF11 3T7 6-8B D7HT4
1TF2 3TF11 6A10 D7T11
1TF20 3TF11B 6A15 D7T4
1TF20A 3TF12 6A25 D7TF10
1TF7 3TF3 6G-12 D7TF7
