APS Power Amplifier 125 & 145

The APS Dynamics Power Amplifiers are designed specifically to provide drive any vibration and modal exciter requiring 500 VA (Model 125) or 810 VA (Model 145). The output stage uses proven high reliability power operational amplifiers arranged to produce a balanced output.

The amplifiers have features which make them uniquely suited for studying the dynamic characteristics of structures. They may be operated in either a voltage or current amplifier mode selectable from the front panel. This operating mode selector switch facilitates shaker drive power interruption, in either a current or voltage mode for observation of resonance decay in structures.

The completely self-contained units are packaged in rugged enclosures suitable for bench or rack mounting. Forced air cooling and massive heat sinks for the output devices insure continuous operation with a shaker delivering rated force into blocked, resistive or reactive loads.

A current monitor signal available on the rear panel permits monitoring of the instantaneous output current amplitude and phase. Electronic protection circuitry will detect an output short-to-ground or overload conditions and remove the drive signal.

Features, Specification


  • Voltage and Current Amplifier
  • Current Monitor Signal
  • Protection Circuitry
  • Forced Air Cooling
  • Delivers Rated Current to Shaker with blocked armature, resonant loads and reactive loads
  • High Reliability Operation


  • Power Output, Max. into 4 Ohm exciter or resistive load: 500 V-A rms (125), 810 V-A rms (145)
  • Voltage Ouput, Max:  45 V RMS DC ... 15 kHz (125, 145)
  • Current Output, Max: 5 A DC  ....  11 A RMS (125), 4 A DC  ....  18 A RMS > 0.1 Hz (145)