What is an AC power source?

An AC Power Source, also known as an AC Power Supply is a device that is capable of supplying variable power and frequency to a load. An AC power source supplies an alternating electrical current that helps power or test a separate piece of equipment by simulating electrical grid interruptions, harmonics, surges, or other events that could cause a device under test (DUT) to malfunction.  AC Power sources such as the IT7321 AC Power source units are commonly used for electrical testing in aviation, lighting, laboratory testing, military and factory production.  This AC Power Source allows you to generate signals of alternating current from 45Hz up to 500Hz. It can also generate different forms of a sine wave including surges, traps, and dimmed phase waves for simulating different events.

AC power has the shape of a sine wave.  On the graph above the amplitude is voltage in volts and the frequency would be measured in periods/second.  In North America the residential electrical grid is most commonly 1 phase 60 Hz 120VAC. In Europe, the grid operates at 50Hz and 230VAC.

Our top models:

ITECH IT7321 150/30V 3/1.5A Programmable AC Power Supply
Figure 2: ITECH IT7321 150/30V 3/1.5A Programmable AC Power Supply

This model uses precision linear amplification. Linearity describes how supply has the ability to produce signals that are accurate copies of the input at varying power and frequency levels. In avionics there are stringent testing requirements, electronics equipment designed for aviation and operation at 400 Hz AC will require testing to demonstrate compliance. An AC power source such as the IT7321 allows you to perform these tests accurately and easily.
Key features: 

  • High accuracy and resolution ±(0.2%+0.6V)/±(0.2%+0.6mA)
  • largest range of frequency (45Hz -500Hz)

Variacs:

Another type of basic and non-programmable AC power supply is a Variac or variable voltage transformer. Variacs work by passing (AC) or Alternating currents through two or more coils (a primary side and a secondary side) in order to transfer electrical energy. Variacs can be used to transfer or convert voltages in order to power devices that can otherwise only run on a specific voltage circuit. Circuit Specialists carries a large selection of variacs including digital panel versions and industrial-strength models with varying levels of output.

Variable Transformer TDGC2-3D with Digital Display & 30 Amp Max Output
Figure 3: Variable Autotransformer with 30 Amp Max Output

This high powered, bench top Variac is one of the most powerful ways to precisely control AC voltage for both laboratory and industrial applications with the largest output range. Key features:

  • Up to 130 Volt range
  • precise, distortion free output

 Single vs. three phase power:

Electricity is mostly generated and transported using three phase power. A single-phase power supply will use two conductors (phase and a neutral) while a three-phase power supply uses only three conductors to transfer three times a much power. Three phase power sources are more environmentally friendly as they require less conductor material to transmit a given amount of power.

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