In Part I, we introduced you to the concept of testing equipment for immunity to voltage dips and short power interruptions in accordance with IEC 61000-4-111. In addition to specifying the test waveforms, the standard also specifies AC source requirements for full compliance testing.

Mains voltage dips and short interruptions can be caused by a wide variety of phenomena and can cause equipment to operate unreliability, and in some cases, can damage the equipment. Faulty loads on an adjacent branch circuit, for example, can cause a circuit breaker to trip, and high-power loads such as welders, motors and electric heaters can cause voltage variations. Natural events, such as power lines downed by storms or lightning strikes, may also disrupt mains power.

Programmable AC power sources are primarily used to provide a low distortion, precisely controlled sinusoidal voltage to a unit under test, but some AC sources, such as the California Instruments I-iX Series II, perform measurements as well. Part 1 describes the benefits of using sources for measurement and how to make voltage and current measurements. Part 2 describes how to make frequency and power measurements. In Part 3, we'll discuss how to make power factor and crest factor measurements using an AC power source.

Programmable AC power sources are primarily used to provide a low distortion, precisely controlled sinusoidal voltage to a unit under test, but some AC sources, such as the California Instruments I-iX Series II, perform measurements as well. Part 1 describes the benefits of using sources for measurement and how to make voltage and current measurements. In Part 2, we'll discuss how to make frequency and power measurements.

The California Instruments iX Series AC/DC Power Source / Analyzer delivers AC, DC, and AC+DC, transient waveforms and performs complex power measurements. While the standard frequency range of the iX Series is 16-500 Hz, it can deliver AC power at up to 1,000 Hz. Many applications, including commercial and military avionics testing, require an output frequency of 800 Hz. The avionics test standards that specify tests at this frequency include:

Programmable AC power sources are primarily used to provide a low distortion, precisely controlled sinusoidal voltage to a unit under test. Increasingly, however, AC sources, such as the California Instruments I-iX Series II, are being used to perform measurements as well. The tight integration between AC source (stimulus) and measurements (response) provides several benefits:

Solar Array Simulation Enables Better PV Inverter Testing for Manufacturers

To ensure that aircraft electronics and other electrically-powered equipment will operate reliably, you must test them under extreme power conditions. In the military world, MIL-STD-704 (now up to rev. F), “Aircraft Electric Power Characteristics,” establishes the requirements and characteristics of aircraft electric power. It deals strictly with power quality, and does not say anything about electromagnetic interference.

While switch-mode power supplies have many advantages, one of their disadvantages is that they are a non-linear load, and because of that can inject harmonic currents into the electrical distribution system. Devices with switching supplies include domestic appliances (TVs, microwave ovens, lighting equipment and dimmers), and office equipment (PCs, printers). Motor-driven equipment can also cause harmonic distortion.