High Voltage Amplifiers


TREK Model 20/20C High Voltage Amplifier

The Model 20/20C is a DC-stable, high-voltage power amplifier used in industrial and research applications such as electrostatic deflection, electrophoresis research, dielectric studies, and accelerated life-testing of high tension cables for power transmission. The Model 20/20C provides precise control of output voltages in the range of 0 to ±20 kV DC or peak AC with an output current range of 0 to ±20 mA DC or peak AC. It is configured as a noninverting amplifier with a fixed gain of 2000 V/V.

The Model 20/20C HV amplifier features an all solid-state design for high slew rate, wide bandwidth, and low-noise operation. The four-quadrant, active output stage sinks or sources current into reactive or resistive loads throughout the output voltage range. This type of output is essential to achieve an accurate output response and high slew rate demanded by a variety of loads such as highly capacitive or reactive loads.

The Model 20/20C is protected against over-voltage and over-current conditions that may be generated by active loads or by output short circuits to ground. This protection includes a user selected TRIP OFF or CURRENT LIMIT value which can be adjusted to a desired level by using a front panel potentiometer. Precision voltage and current monitors provide low-voltage representations of the high-voltage amplifier output and load current for monitoring purposes or for use as feedback signals in a closed-loop system.

The Remote High-Voltage On/Off feature provides a connection for a remote device to turn on and off the high voltage of the instrument. This makes the Model 20/20C suitable for automated or computer controlled systems.

The Model 20/20C can be operated on a bench top or in a standard 19-inch rack.

 

Show/Hide Product Technical Information

AMPLIFIER INPUT & Output

  • Output Voltage Range
    0 to ±20 kV DC or peak AC.
  • Output Current Range
    0 to ±20 mA DC or peak AC.
    (See Automatic Power Limit feature for limitations.)
  • Input Voltage Range
    0 to ±10 V DC or peak AC.
  • Input Impedance
    25 kohm, nominal.

PERFORMANCE

  • DC Voltage Gain
    2000 V/V.
  • DC Voltage Gain Accuracy
    Better than 0.1% of full scale.
  • Offset Voltage
    Less than ±2 V.
  • Output Noise
    Less than 1.5 V rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter).
  • Slew Rate (10% to 90%, typical)
    Greater than 450 V/µs.
  • Large Signal Bandwidth (-3dB)
    DC to greater than 7.5 kHz.
  • Large Signal Bandwidth (1% distortion)
    DC to greater than 3.75 kHz.
  • Small Signal Bandwidth (-3dB)
    DC to greater than 20 kHz.
  • Settling Time (to 1%)
    Less than 150 µs for a 20 kV step.
  • Stability
    • Drift with Time
      Less than 50 ppm/hr, noncumulative.
    • Drift with Temperature
      Less than 100 ppm/°C.

PRODUCT FEATURES

  • High-Voltage Amplifier On/Off
    Switch selectable for either local or remote control.
    • Local
      Individual push-button switches.
    • Remote
      A TTL compatible input. A TTL high (or open) turns off the high-voltage amplifier output. A TTL low turns on the high-voltage amplifier output.
  • Dynamics Adjust
    A graduated one-turn panel potentiometer used to optimize the AC response of the Model 20/20C under various load conditions.
  • Current Limit/Trip
    Switch selectable for either limit or trip. A graduated one-turn panel potentiometer is used to adjust the limit or trip level from 0 to 20 mA.
  • Out of Regulation Status
    An indicator will illuminate and a BNC will
    provide a TTL low when the Model 20/20C fails to produce the required high-voltage output such as during current limit or short circuit load conditions.
  • Trip Status
    An indicator will illuminate and a BNC will provide a TTL low when the high-voltage amplifier output is disabled due to:
    • the output current exceeding the current trip level,
    • the detection of a high-voltage power supply fault, or
    • the removal of the top cover.
  • Fault Status
    A BNC will provide a TTL low when the Model 20/20C is out of regulation for greater than 500 ms.
  • Voltage Monitor
    A buffered output providing a low-voltage replica of the high voltage output.
    • Scale
      1/2000th of the high-voltage output signal.
    • DC Accuracy
      Better than 0.1% of full scale.
    • AC Accuracy
      Calibrated against a Ross Model VD 30-4.1-BD-KC-ALU high-voltage divider.
    • Offset Voltage
      Less than ±2 mV.
    • Output Noise
      Less than 10 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter).
    • Output Impedance
      47 ohms.
  • Current Monitor
    A buffered output providing a low-voltage representation of the load current.
    • Scale
      0.5 V/mA.
    • DC Accuracy
      Better than 1% of full scale.
    • Offset Voltage
      Less than ±10 mV.
    • Output Noise
      Less than 30 mV rms (measured using the true rms feature of the Hewlett Packard Model 34401A digital multimeter).
    • Bandwidth (-3db)
      DC to greater than 10 kHz.
    • Output Impedance
      47 ohms.
  • Automatic Power Limit
    Automatically limits the output power to protect the Model 20/20C from overheating due to excessive internal power dissipation. The following graph illustrates the Model 20/20C operating range automatic power limits.

GENERAL

  • Dimensions
    279 mm H x 482 mm W x 654 mm D
    (11" H x 19" W x 25.75" D).
  • Weight
    24.9 kg (55 lb).
  • High-Voltage Output Connector
    Caton high-voltage connector.
  • Amplifier Input
    BNC connector.
  • Voltage Monitor Connector
    BNC connector.
  • Current Monitor Connector
    BNC connector.
  • Remote High-Voltage On/Off Connector
    BNC connector.
  • Out of Regulation Status Connector
    BNC connector.
  • Fault/Trip Status Connector
    BNC connector.
  • AC Line Receptacle
    16 A at 230 V AC or 20 A at 125 V AC.
  • Power Requirements
    • Line Voltage
      Factory set for one of two ranges:
      104 to 127 V AC or 180 to 250 V AC, at 48 to 63 Hz.
      (Specify when ordering.)
    • Power Consumption
      1000 VA, maximum.
  • Operating Conditions
    • Temperature
      0 °C to 40 °C.
    • Relative Humidity
      To 75%, noncondensing.


ACCESSORIES SUPPLIED

Operator’s manual, Caton 5 m (16 ft) high-voltage output cable assembly, and line cord.

CERTIFICATION & COMPLIANCE

Certification
TREK, INC. certifies that each Model 20/20C is tested and calibrated to specifications using measurement equipment traceable to the National Institute of Standards and Technology or traceable to consensus standards. A Certificate of Calibration accompanies each instrument when it is shipped from the factory.

Low-Voltage Safety Compliance (EN 61010-1)

Installation Category
CAT II: Local level mains, appliances, portable equipment.
Pollution Category
Degree 1: Operate in environments where no pollution or only dry, nonconductive pollution occurs.

All specifications are with no load unless otherwise noted.
All specifications are subject to change.

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