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Digital Energy Analyzer

The Digital Energy Analyzer measures and prints voltages, currents, powers, power factor and distortions; it also measures total and and time-band energy consumption. Aside the instantaneous readings it also provides average values and maximum power and distortion readings. The analyzer has the ability to function as harmonic analyzer as well.

In the early ’90s the apparition of commercially available data acquisition cards for PC made possible the development of virtual instrumentation. The Digital Energy Analyzer was implemented as a virtual instrument in two versions using:

  • NI LabPC+ DAQ card from National Instruments Corporation
  • a low cost custom designed DAQ module intended to be part of a turnkey system

Block Diagram:

Digital Energy Analyzer


  • Low-cost data acquisition module: hardware design, prototype, device drivers
  • Measurement probes and signal conditioning
  • Signal processing and measurement module (voltages, currents, powers, power factor and distortions)
  • Energy measurement module (total and and time-band energy counters)
  • Implementation of real-time Fast Fourier Transform for the spectrum analysis module
  • Data logging and system interface

All the software development was done in ANSI C using LabWindows/CVI from National Instruments Corporation.