PSU-S1 The PSU-S1 is a power supply module in a 6U Eurocard form factor. Intended for use as a Bus and Bias supply for high voltage Western Servo Design amplifiers (e.g., PAU, and BPU), the PSU-S1 can be used in a Eurocard (or "VME") style chassis, or as a stand alone unit.

The PSU-S1 contains an unregulated DC Bus output, a regulated Bias output (12VDC), a 12VDC output for cooling fans, and a built-in Shunt Regulator. When PWM amplifiers are used, the Shunt Regulator prevents back EMF generated by the motors from damaging components in the Bus Supply and Amplifiers.

An optional backplane is available to allow quick and easy access to the inputs and outputs for the power supplies and the Shunt Regulator. This greatly simplifies implementing the PSU-S1 in a motion control system.


  • Eurocard 6U Form Factor
  • Contains Bus Supply, Bias Supply and 12VDC Fan Supply
  • Built-In Shunt Regulator
  • Front Panel Status LEDs for Bias Supply, Fan Supply and Shunt Regulator Fuse
  • 30 Amp and 50 Amp Models Available
  • Optional Backplane Simplifies System Connection
  • Advanced Design, High Quality and High Reliability at a Lower Cost


Standard Models:



Maximum AC Input Voltage 230 VAC 230 VAC
Minimum AC Input Voltage 100 VAC 100 VAC
Bus Voltage Output Approximately 1.4 x VAC in: 320 VDC Max Approximately 1.4 x VAC in: 320 VDC Max
Bus Output Current* 30A Continuous 50A Continuous
Bias Voltage Output +12VDC @ 2A, -12VDC @ 1A +12VDC @ 2A, -12VDC @ 1A
Cooling Fan output 12VDC @ 1A 12VDC @ 1A
Shunt Regulator Load 10 to 15 Ohms @ 200W or more 10 to 15 Ohms @ 200W or more
Weight 2.90 Lbs (1.32 Kg) 2.90 Lbs (1.32 Kg)
Recommended Chassis CH6U Eurocard CH6U Eurocard
Available Accessories Backplane Backplane

*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.

The PSU-S1 can be connected directly to single-phase or three-phase AC. With a 120VAC input, the Bus Voltage will be 170VDC. With a 230VAC input, the Bus Voltage will be 320VDC.

Ordering Information

Product Order Number
PSU-S1-32/30 Power Supply 320VDC/30A Cont. WS-009-0002
PSU-S1-32/50 Power Supply 320VDC/50A Cont. WS-009-0005
ACC-V1Y Backplane WS-011-0002

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All data sheets are in Adobe Acrobat format.