Surges are a key problem in electronics since they are every circuit developer’s biggest concern. These surges are usually referred to as impulses, which have the distinct characteristics of high voltages, typically in the kV range, that remain for a brief period. The features of an impulse voltage may be identified by a high or low fall time followed by a very high voltage increase time. An example of impulse voltage from a natural cause can be lightning. Let’s find out more about the working principal of the unit. Read on to find out more.

EMC Testing; Conducted & Radiated Immunity & Susceptibility

Since this impulse voltage may appear to be extremely harmful to electrical equipment, it is crucial to test the gadgets to ensure that they can withstand it. This is where a surge generator, which creates high voltage or current surges, comes in handy.

The EC 61000-4-5 standard specifies the immunity criteria, test methodologies, and the range of standard testing levels for equipment against unidirectional surges generated by overvoltage from switching and lightning transients. The testing levels for electrical and electronic equipment are determined depending on the environment and installation circumstances. The primary goal of this standard is to create a consistent reference for measuring the resistance of electrical and electronic equipment to surges.

Surge Protection IEC 61000-4-5 Immunity stress is intended to be indicative of voltage or current pulses that are generated on power networks by events that occurred outside of the equipment under test. Surges can be caused by power system switching transients, such as capacitor bank switching or load shifts. Surges on electrical lines could also be caused by lightning, either as a direct hit to a transmission line or as a result of a surrounding lightning strike.

A surge generator is used to accomplish the capacitor discharge technique. This equipment transforms line power into high voltage, unidirectional impulses, which are then sent through a faulty power connection. Capacitor charges are proportional to the voltage of the power supply. When the switch is closed, the capacitor discharges a high voltage impulse into the cable under test. Upon analyzing the findings, the curve illustrates how time influences the voltage at which a gap will flash over.

The smaller the time delays before flashover, the greater the applied voltage.
There is often a small and minimal time lag and below which the gap can never flash over.
A minimal amount voltage, shown by the ‘Minimum Break-down Voltage, ‘ exists below which a gap will not flash over within a normal test time of several minutes.

In short, the surge generator, aka a thumper, is an important component when it comes to locating cable faults. The voltage and energy capability of the gadget evaluate the effectiveness with which defects can be broken down and found. When choosing a unit, consider the type of cabling and total length being tested. Hope this helps.

The measuring receiver (spectrum analyzer or EMI receiver) is among the most valuable pieces of equipment available in an Electromagnetic Compatibility (EMC) lab or engineering facility. Measuring receivers of various types are used to detect and fix EMI issues that frequently emerge during the early stages of the product development phase. After the design team makes all EMI adjustments, measurement receivers are utilized to undertake full-compliance certification testing before shipping the finished product to customers. Let’s find out more about these units.

These measuring receivers and spectrum analyzers, like oscilloscopes, are fundamental instruments for viewing RF signals. On the other hand, as a measuring receiver looks at signals in the frequency domain, oscilloscopes look at signals in the time domain.

Electromagnetic compatibility (EMC) refers to an electronic device’s ability to function in an electromagnetic environment without interfering with or being affected by other electronic devices in that space. EMC testing is generally classified into two types:

Emissions are electromagnetic disturbances emitted by a piece of electronic equipment that may cause disruptions or failure in another electronic device in the very same environment.
Immunity/Susceptibility – Immunity is an electronic equipment’s capacity to perform properly in an electromagnetic environment without encountering disruption as a result of emissions from another electronic device.
The nature of the equipment being tested, its intended purpose, and the regulatory constraints regulating its usage all influence the EMC testing process. EMC testing may simulate the following electromagnetic phenomena:
Magnetic fields, like those emitted by electric lines
Voltage lowers as a result of a brownout or other power outage.
Lightning-caused electromagnetic spikes
Electromagnetic noise that is both conducted and emitted
Static electricity causes electrostatic discharges.
Why Conduct an EMI Test?
There are numerous factors why EMI testing is postponed till the end of a project. The first is the apparent difficulty of conducting this sort of testing. However, there are specialized labs with all of the necessary equipment and personnel on hand to assist.

Another frequent misperception is that power supplies are the primary source of EMC problems and that if a power supply passes its standalone testing, the system into which it is plugged will likewise pass. It does not operate that way as power supplies serve as the “messenger” rather than the source of EMC issues.

There’s also the matter of cost. Making modifications to your design as you approach production is much more costly than doing it earlier in the process. Also, the cost of earlier screening tests is far cheaper than those of full-scale certification testing. The earlier you detect issues, the less expensive they are to repair.

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