The LDH-S2 is a low power brushed linear servo amplifier in a 3E Edge Mount format. It is ideally suited to "stand alone" torque or velocity control applications or for position/velocity/acceleration control if used with a motion controller and position feedback device. When configured for torque control, the amplifier operates as a voltage controlled current source. When configured for velocity control, the amplifier operates as a voltage controlled voltage source. If configured for velocity control, the amplifier can be further configured to accept a tachometer feedback signal for improved motor response, low speed smoothness and velocity accuracy.

The LDH-S2 has simple potentiometer adjustments for Signal Gain, Tachometer Gain, System Response and Balance. The unit includes an Amp Enable input and Enable Indicator LED. Until the amplifier is enabled, the command input is essentially zeroed and the output transistors disabled. Look to the LDH-S3 for added RMS fault protection. The LDH-S2 has numerous advantages over PWM type amplifiers including minimum motor heating, increased brush life, high bandwidth, and the ability to drive zero inductance loads.


  • 3E Edge Mount
  • Torque/Velocity Mode Jumper Selected
  • Can Accept Tachometer Input in Velocity Mode
  • Disable Signal Zeroes Command Input and Disables Motor Output
  • Amp Enable Input and Indicator LED
  • Minimum Electrical Noise
  • Drives Zero Inductance Loads
  • Accepts Uni-polar or Bi-polar Bus Supply
  • Bus Voltage: 20 - 40 VDC
  • Continuous Current: 2 Amperes
  • Excellent for use with Precision Positioning Systems
  • Design for Brushed DC Motors
  • Advanced Design, high Quality and High Reliability at a Lower Cost
  • One Year Parts and Labor Warranty


Standard Models: 4/5
Bus Voltage 20 to 40  VDC
Peak Output Current* 5 A for 0.5 Sec
Continuous Output Current* 2 A
Command Input Voltage 0 to 10V
Tachometer Input Voltage 0 to 40V
Command Input Impedance 20 kOhm
Tachometer Input Resistance 20 kOhm
Minimum Load Inductance 0 H
Torque Gain 0.5 A/V
Bandwidth 20 kHz
Weight 0.25 Lb (113 g)
Recommended Chassis LDP, EPS

*All ratings with forced air cooling to maintain 40C heat sink temperature. Failure to keep constant air flow to the heat sink will reduce the output current capacity and may result in damage to the unit.

Ordering Information

Product Order Number
LDH-S2-4/5 Amp 40 VDC/5A Peak WS-000-0006

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