The PDH-S3 is a medium power, brushed PWM servo amplifier in a 3E Edge Mount package. This multi-purpose amplifier contains both Velocity and Torque feedback loops. Inputs are provided to allow tachometer feedback in the Velocity Mode. The Torque Mode can be used for torque control applications, or in conjunction with a digital servo controller capable of computing Position and Velocity loop values. The Torque Mode can also be used for feedback in the Velocity Mode, with or without a position controller. The high switching frequency of the PDH-S3 allows the amplifier to drive very low inductance loads. Potentiometer adjustments for Signal Gain, Tach Gain, System Response, and Balance are provided. This amplifier is functionally similar to the PDH-S2 (which it replaces), and is built with Surface Mount ciruitry.

The Travel Limit and Amp Enable inputs are jumper selectable to accept normally open or normally closed switches.

The PDH-S3 has over and under voltage shutdown as well as over current protection. Two LEDs indicate power on and fault conditions. An Amp Fault output can be used to indicate a fault condition to an external controller.


  • 3E Edge Mount Packaging
  • No External Bias Supply Required
  • Shutdown in Over Voltage, Under Voltage, and Over Current Conditions
  • Global "Amplifier Fault" Output
  • Jumper Selectable Velocity or Torque Modes
  • Jumper Selectable Switch Type (N.O. or N.C.) for Enable and Limit Inputs
  • "Power On" and "Fault" LEDs
  • PWM Frequency: 20 or 40 kHz
  • Continuous Current: 5 or 10 Amperes
  • High Bandwidth
  • Bus Voltage: 20 - 60 VDC
  • Advanced Design, High Quality and High Reliability at a Lower Cost
  • One Year Parts and Labor Warranty


Standard Models: 6/10 6/20
Bus Voltage 20 to 60  VDC 20 to 60 VDC
Peak Output Current* 10 A for 0.5 Sec 20 A for 0.5 Sec
Continuous Output Current* 5 A 10 A
Command Input Voltage 0 to 10V 0 to 10V
Tachometer Input Voltage 0 to 40V 0 to 10V
Command Input Impedance 20 kOhm 20 kOhm
Switching Frequency 40 kHz 20 kHz
Minimum Load Inductance 0.2 mH 0.2 mH
Torque Gain 1.0 A/V 2.0 A/V
Bandwidth 20 kHz 4 kHz
Weight 0.28 Lb (127 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
PDH-S3-6/10 Amp 60 VDC/10A Peak WS-003-0008
PDH-S3-6/20 Amp 60 VDC/20A Peak WS-003-0009

 Click here to download this data sheet.

All data sheets are in Adobe Acrobat format.