Ballantine 1620A

0 - 100 amp Tansconductance Amplifier


This Ballantine 1620A Transconductance Amplifier has one of  the broadest current calibration ranges on the market.  It can function as a stand alone unit using the front panel controls or as part of a system using the IEEE interface and I/O remote expansion slot.  It provides peak outputs of over 200 amps.  This is a current product and is in excellent physical and electrical condition.  It includes high current input connectors.  Manuals for this unit are available from Ballantine for $150.

Product Summary

The BLI 1620A Transconductance Amplifier is designed to provide calibration and test departments a highly accurate, highly precise, high current calibration source.

The 1620A provides high accuracy current levels from dc to over 10 kHz for calibrating ammeters, current transformers and shunts. It also provides output current up to 100 Amperes. and as such may also be used as a high accuracy power supply, and as a power source in welding and bonding applications.

The 1620A converts a signal voltage applied to its input, into a high resolution output current whose value is directly proportional to the input signal level. As a example, if an input of 2 Volts is applied on the 20 Ampere range, a current of 20 Amperes will be produced at he output terminals. With dc input voltages, the output current provides the same polarity as the driving signal, and with ac inputs the output will faithfully reproduce the frequency, phase, waveshape, symmetry and dc offset of the input source. A wide range of currents can be produced with seven switchable ranges from 200 microamperes to 100 Amperes rated for positive or negative dc and ac sinusoidal rms at crest factor to 1.45 maximum. Signal inputs can be up to 100 Volts above or below the earth grounded enclosure.

The 1620A can be driven by commercially available manual or programmable, precision ac or dc voltage calibrators and sources, and when equipped with the IEEE-488 option a fully automated current calibration system can be configured to optimize throughput in calibration procedures.

Product Features

  • 200 Amp Capability in Pulsed Mode
  • Paralleled Operation for High Current Capability
  • Improved linearity and reduced Temperature Coefficients
  • Calibrates AC or DC ammeters, shunts, and current transformers.
  • High accuracy of 0.02% of DC range; 0.15% of AC range.
  • Output current bandwidth DC to over 10kHz. 1kHz at 100A RMS.
  • Low distortion of less than 0.1% of fundamental.
  • IEEE-488 Programmable.
  • Full overload protection.

Product Specifications

AC Mode


0 to 100A rms, at 100 Siemens
0 to 20A rms, at 10 Siemens
0 to 2A rms, at 1 Siemens
0 to 200mA rms, at 100 milliSiemens
0 to 20mA rms, at 10 milliSiemens
0 to 2mA rms, at 1 milliSiemens
0 to 200mA rms, at 100 microSiemens

Ratio of Input Voltage to Output Current:

All ranges: 2 Volts input for full range current output, except 100A range which is 1 Volt for 100A rms output current. AC rms is rated for sinusoidal inputs with a maximum crest factor of 1.45 at full range current output, and greater than 3 at midrange.

Resolution: (Referred to input voltage)
1mA on the 200mA range.
0.01% of range on the 2mA to 20A ranges.

Compliance Voltage:
100A range: 3 Volts rms (4.2 Volts peak)
20A range: 4 Volts rms (5.6 Volts peak)
:All other ranges: 5.5 Volts rms (7.7 Volts peak)

Open Circuit Compliance Voltage:
Not greater than 15 Volts peak.

Accuracy of Output Current:
Allowable deviation of range output current input voltage:
(0.15% of output current +0.1% of range) to 1 kHz.

Bandwidth (Sinusoidal input):
100A range: DC to 20 Hz to 100 Amps peak
20 Hz to 1 kHz to 100 Amps rms
20A range: DC to 1 kHz
2A range DC to 5 kHz
All other ranges: DC to > 10 kHz

Load Regulation/Transient Recovery Rime:
Output Current settles within 0.01% of initial value in 5 seconds with any change in load.

Total Harmonic Distortion:
< 0.1% of the fundamental at 100A rms and 1 kHz sinewave.

Load Requirements: The current output will supply resistive and capacitive loads as well as inductive loads to 2 millihenries at full specified currents and frequencies which permit operation within the rated compliance voltage.

DC Mode

Ranges and Transconductance:
0 to 100A at 100 Siemens
0 to 20A at 10 Siemens
0 to 2A at 1 Siemens
0 to 200mA at 100 milliSiemens
0 to 20 mA at 10 milliSiemens
0 to 2 mA at 1 milliSiemens
0 to 200mA at 100 microSiemens

Ratio of Input Voltage to Output Current:
All ranges 2 Volts input for full range current output; except 100A range which is 1 Volt for 100A output current.

Resolution: (Referred to input voltage)
1mA on the 200mA range.
0.01% of range from 2mA to 20A ranges.

Compliance Voltage: 4 Volts minimum on the 20A and 100A ranges. 7.5 volts minimum on all other ranges.

Open Circuit Compliance Voltage:
Not greater than 15 Volts peak.

Accuracy of Output Current:
Provides accuracy of (0.02% of output current +0.02% of range) on all the ranges.

Load Regulation: to 10%; 50 to 400 Hz
Transient Recovery Time: Output current settles within 0.01% of initial value in 5 seconds with any change in load.


Input Terminals and Impedance: Gold plated universal binding posts. 10 Megohm input resistance.

Output Terminals: Gold plated, universal binding posts on all ranges except 100A range which uses Superior Model RS 100G high current female terminals.

Rear Input: Front or rear input selectable by front panel switch.

Off ground Operation: Instrument is capable of operating input LO and output LO to 100V dc with respect to case ground input. LO to case resistance: 0.5 Megohm

Isolation: Input voltage LO may be separated by 10 volts common mode voltage with respect to output current HI and LO terminals.

Environmental Characteristics:
Designed to comply with MIL-T-28800, Class 5.
Storage: -40 to +75o C
Operation: 0 to 50o C
Full Accuracy: 20% to 80% RH to 40 o C
Usable: 10% to 100% RH without condensation
Storage: 0 to 15 Km (50,000 ft.)
Operating: 0 to 3 Km (10, 000 ft.)

Controls and Indicators:
ON-OFF Power Switch
FRONT/REAR Input Switch - Selects front or rear panel input voltage terminals
RANGE - 6 push-button switches select one of seven ranges.
OVERCOMPLIANCE Indicator - Lights when load compliance voltage is exceeded.
INPUT OVERDRIVE Indicator - Lights when input drive voltages are exceeded.
OPERATE/STANDBY Switch - Disables output current drive.
REMOTE Indicator - Lights when remote operation is selected.

Input Protection: to 200 Vrms.
Output Protection: Open circuit or short circuit protection and output compliance voltage limited to 15 volts peak across current output terminals.
Sensitive components protected by high temperature cut out with auto reset and "standby" indicator.
Ventilation: Forced air ventilation is provided whenever interior temperature rises above 50 Degrees Celsius.

Height: 267 mm (10 1/2")
Width: 19" standard EIA rack mount configuration
Depth: 416 mm (16 3/4") behind panel, 457 mm (18") overall
Weight: 50 kg (80 lbs.)
64 kg (110 lbs.) shipping

Power Requirements: 100V or 120V or 220V or 240V 10%. Single phase, 50 to 60 Hz 2 KVA. Fully protected with 20A magnetic circuit breaker.



As our many customers will attest, we will do our very best to resolve any customer problems.  But our official policy is: All items sold are guaranteed against D.O.A. only. All claims must be made within 3 days of receipt.   All warranties are void if the calibration / warranty seals are broken. 

Ascent Concepts and Technologies is a Research & Development Lab.  As a service to the companies and institutions we work with, we broker their excess equipment & acting as application specialists on their new equipment needs.  We are now offering quality used equipment to the public with the same level of professionalism and service.   Please feel free to email at or call Thomas @ 1-303-554-0307 with any Technical questions. Please feel free to email at or call Walt @ 1-720-276-8288 with any Shipping or Logistical questions.   We make every effort to evaluate and guarantee our equipment.  Although we do not provide NIST traceable calibration, we do have in house calibration equipment and will make every effort to test and verify performance on equipment we sell.  However we do not warranty any items shipped outside the United States.  All equipment we sell comes with a three day right of return unless stated otherwise.

Shipping Policy

Buyer will pay $30 packing & actual shipping costs.  We will make every effort to ship within 24 hours of receipt of payment.  We ship with FedEx & UPS only. We will be glad to ship with other carriers using the purchasers shipping account.  Please contact us to make any special shipping arrangements. For shipping rate research, our shipping address is Boulder, CO USA ---- Zip Code is 80305.. 

Note : This unit is 110lbs.  It will be expensive but it can be shipped by FedEx & UPS.  

Foreign buyers:  Unless special provisions have been made, you are responsible for making your own shipping arrangements and all costs related to customs, duties & special packaging requirements.  Please do not ask us to quote you international shipping rates. Use the address information above to research you own shipping rates. You can email to get the packaging fee, package weight and size for your research. Items sold outside the USA are sold as is.  


 Payment Policy

We accept Credit Card payment through Paypal.   We accept Cashiers Check or Money Orders.