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      • LA-200/400/500 Series Linear Amplifiers
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      • LALD-400/500/800/1500 Series Low Drift Linear Amplifiers
      • LA6U Series Modular Multi-Axis Amplifiers
    • Intelligent Linear Servo Amplifiers
      • VLA4 Series Intelligent Linear Amplifiers
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      • VSA1 / VSA2 Series Digital PWM Servo Amplifiers
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Call us 310-542-2320

info@varedan.com
Varedan Technologies Varedan Technologies
  • Home
  • Products
    • Analog Linear Servo Amplifiers
      • LA-200/400/500 Series Linear Amplifiers
      • LA-800/1500 Series Linear Amplifiers
      • LALD-400/500/800/1500 Series Low Drift Linear Amplifiers
      • LA6U Series Modular Multi-Axis Amplifiers
    • Intelligent Linear Servo Amplifiers
      • VLA4 Series Intelligent Linear Amplifiers
    • Digital PWM Servo Amplifiers
      • VSA1 / VSA2 Series Digital PWM Servo Amplifiers
    • Power Supplies & Transformers
  • Servo Amplifier Sizing & Tools
  • Company
  • News
  • Contact Us
    • FAQ / Support Center
    • Returns/Repairs
Linear Servo Amplifiers

LALD-400/500/800/1500 Series Low Drift Linear Amplifiers

The LALD (linear amplifier, low drift) Linear Servo Amplifiers are designed for high precision applications which require ultra-low current drift, in the range of micro amps per degree C. Furthermore, Varedan’s proprietary circuitry provides gain switching to allow very accurate low-level current (<500mA) control. This design is inherently balanced and requires no extra setup or adjustment for operation. These high power linear amplifiers are well suited to drive loads such as brushless and brush servo motors or voice coils. Our designs incorporate class AB linear output stages for true linear output.

The design of these amplifiers includes an onboard high-speed DSP that monitors all key system functions in real time, and provides protection for the output bridge by limiting power to a “Safe Operating Area”. An intelligent user interface allows setup and storage of all system parameters via the serial interface. Non-volatile memory provides storage of the parameters during power off conditions.

Modes of Operation

Current Mode

In current mode the amplifier is commutated by an external controller. Our Linear Amplifier Series are designed to drive single & 3-phase loads by analog input commands.

These current mode linear amplifiers are available in the following standard configurations:

“T-Mode” – Three-phase current output. This configuration is used for driving three phase rotary or linear motors with a full-bridge output configuration. In this configuration the amplifier receives two sinusoidal current commands for phases A and B (ABSine). The phase C command is generated internally in the amplifier.

“S-Mode” – Single-phase H-Bridge type output. This configuration is used for driving single phase loads such as brush-type motors or voice coils. In this mode the amplifier can deliver the full rail-to-rail bipolar bus voltage to the load.

The following is an example of S-Mode operation.  When operating in full-bridge configuration (Phase to Phase), the maximum bus voltage that can be applied to the voice coil is the full B+ to B- voltage.  For example if you are using a +/-50VDC bus and a full-bridge connected voice coil, the maximum voltage that can be applied to the voice coil is +100V or -100V.  This is illustrated in the following picture which shows positive current from PhaseB to PhaseC (+100V):

Linear Amplifier Sizing
S-Mode Operation

“D-Mode” – Dual independent Half-Bridge type outputs. This mode is used to drive two independent single phase loads, such as brush-type motors or voice coils, with one amplifier module. In this mode the amplifier can deliver half of the full rail-to-rail bipolar bus voltage to the load. The sum total wattage requirements of the two independent loads must be within the capabilities of the amplifier module.

The following is an example of D-Mode operation, (or one or two voice coil connected to a T-Mode amplifier).  When operating in Half-Bridge configuration (Phase to Common), the maximum bus voltage that can be applied to the voice coil is 1/2 of the full +/-Bus supply.  For example if you are using a +/-50VDC bus and a half-bridge connected voice coil, the maximum voltage that can be applied to the voice coil is +50V or -50V.  This is illustrated in the following picture which shows positive current from phaseB to Common (+50V):

Internally Commutated Current Mode

Our optional VMC2* plug-in board can interface with the encoder to allow the amplifier full sinusoidal commutation.

Velocity Mode & Position Mode

Our optional VMC2* plug-in board can interface with your feedback device to provide velocity & position mode.

*Please contact Varedan for more information.

linear Amplifier Sizing
D-Mode Operation

Request Application Assistance

Tell us about your application so we can help you select the right solution.

Please use this fillable PDF form to guide you through the information about your application that we need to properly size and select an amplifier for your application.  Please also see out Amplifier Sizing & Tools page for sizing calculators, white papers and other tools.

Standard Models

Amplifier SeriesCurrent Continuous/Peak Power Continuous/Peak ±VDC Bus VoltageDimensionsWeight
LALD-4155/15 Amps400/1800 Watts±12 - ±150VDC7.50” x 8.00” x 2.612"3.6 pounds
LALD-52510/25 Amps500/1900 Watts±12 - ±150VDC7.50” x 8.00” x 2.612"4.6 pounds
LALD-53515/35 Amps500/3800 Watts±12 - ±150VDC7.50” x 8.00” x 2.612"4.6 pounds
LALD-82515/25 Amps800/1900 Watts±12 - ±150VDC7.50” x 8.00” x 3.871"7.8 pounds
LALD-83515/35 Amps800/3800 Watts±12 - ±150VDC7.50” x 8.00” x 3.871"7.8 pounds
LALD-152515/25 Amps1500/1900 Watts±12 - ±150VDC7.50” x 8.00” x 4.871”9.8 pounds
LALD-153515/35 Amps1500/3800 Watts±12 - ±150VDC7.50” x 8.00” x 4.871”9.8 pounds

Key Design Benefits

  • Linear Output Control for quiet operation
  • True Rail to Rail Output
  • Multiple power levels share common interface
  • Single-Phase, Three-Phase and D-Mode
  • Safe Operating Area Protection of Power Devices
  • Zero Crossover Distortion
  • Extremely Low Drift
  • Over Current Protection
  • Over Voltage Protection
  • Up to 10kHz Bandwidth
  • Non-Volatile Storage of All System Parameters
  • Serial User Interface for Programming/Monitoring
  • Configure Using Serial Interface
  • 7-Segment Display Shows Status in Real-Time
  • Factory or Customer Programable Options:
    • RMS Over-current Trip Level
    • RMS Over-current Trip Time
    • Absolute Over-current Trip Level
    • Enable level
    • Enable Source
    • Fault level

Models & Specifications

  • LALD-400/500 Series
  • LALD-800 Series
  • LALD-1500 Series
Package Type DatasheetInstallation DrawingManualSTEP File
Amplifier Module - For high density or OEM applications. Available with or without covers.
Stand-Alone Amplifier Package - For "plug & play" applications. Available in a fully enclosed package with built in fan and power supply.Contact Varedan
Contact Varedan
2 Axis Package with 500VA Power Supply (isolation transformer included) - Mounted on a baseplate with built in fan & power supply.Contact Varedan
Contact Varedan
2 Axis Package with 1KVA Power Supply (isolation transformer included) - Mounted on a baseplate with built in fan & power supply.Contact Varedan
Contact Varedan
2 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan
4 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan
Package Type DatasheetInstallation DrawingManualSTEP File
Amplifier Module - For high density or OEM applications. Available with or without covers.
1 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan
2 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan

Package Type DatasheetInstallation DrawingManualSTEP File
Amplifier Module - For high density or OEM applications. Available with or without covers.
Single Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan
2 Axis Package (needs external isolation transformer) - Mounted on a baseplate with built in fan.Contact Varedan
Contact Varedan

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  • Varedan Technologies
  • 3860 Del Amo Blvd., Suite 401 Torrance, CA 90503
  • 310.542.2320
  • 310.542.2344
  • info@varedan.com
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© 2019 · Varedan Technologies

  • Home
  • Products
    • Analog Linear Servo Amplifiers
      • LA-200/400/500 Series Linear Amplifiers
      • LA-800/1500 Series Linear Amplifiers
      • LALD-400/500/800/1500 Series Low Drift Linear Amplifiers
      • LA6U Series Modular Multi-Axis Amplifiers
    • Intelligent Linear Servo Amplifiers
      • VLA4 Series Intelligent Linear Amplifiers
    • Digital PWM Servo Amplifiers
      • VSA1 / VSA2 Series Digital PWM Servo Amplifiers
    • Power Supplies & Transformers
  • Servo Amplifier Sizing & Tools
  • Company
  • News
  • Contact Us
    • FAQ / Support Center
    • Returns/Repairs