How is a LISUN transient generator used in automotive industry

What is an automotive transient generator?
An automotive transient generator is used to test automotive components. This testing is done for EMI, surges and current dips. These problems could cause the vehicle to shut down or damage electrical components. Transient immunity in automotive components is governed by the ISO 7637 test standard. The development of automotive technology has led to the integration of high quality, more intricate electrical systems into vehicles. These are dependent on effective communication between sensors and control systems. Automobile immunity testing is becoming more difficult. This is since new electrical components are more vulnerable to vehicle EMI.

Testing with an ISO 7637 transient generator
An ISO 7637 transient generator facilitates car EMC testing. Automotive transient immunity generators are designed to generate waveforms. These are similar to real world car difficulties. When you crank the ignition, surges are generated that can overload components. These components include stereo, turn signals, and even the battery and alternator. A load dump is another reason, which occurs when the battery disconnects while being charged by the alternator and the vehicle dies. Several immunity tests are carried out in order to duplicate these conditions.

What is EMC testing?
EMC testing is a procedure in which test experts look for disruptive electromagnetic radiation. They also guarantee that gadgets do not accidentally emit RF signals. An ISO 7637 transient generator facilitates EMC testing. It enables specialists to quickly and precisely detect system faults within a vehicle. This advantage will ultimately save you both time and money.

EMS-ISO7637 Multifunctional Immunity Test System For Automotive Electronics

What is the function of an iso 7637 transient generator?
ISO 7637 test equipment uses voltage and current during the testing process. The device generates waveforms that mimic real-world automotive problems. Technicians can alter variables on the ISO 7637 transient generator’s interface. This is done to perform tests. These tests can include load dump testing, voltage drop testing, and more. Test engineers reference ISO and OEM test requirements. This is done to obtain automotive EMC compliance.

Automotive immunity testing
• Electrical fast transient (eft/burst)
• Load dump
• Micro pulse (surge)
• Power fail simulators
• Transient emissions
• Voltage drop simulation

The method of testing will determine the necessary connections and supplementary equipment. Two primary ways are employed with these conducted immunity test systems. These are the coupling decoupling network (CDN) or direct-out connections. When the EUT/DUT is not powered on, the direct-out can be utilized for testing, as can a capacitive coupling clamp (ccl). These procedures are frequently referred to by the underlying standard or associated test plan. Testing should be carried out in accordance with them.

Power-on testing – testing through the CDN
Testing with the power turned on CDN testing is often performed. This is done while the equipment under test is operational and provides insight into the impact the event will have on the operations of the EUT. It is customary to have either a EUT supply adapter from the CDN output (generally incorporated into the generator). Or a EUT power separated away by lines for easier connection to the EUT/DUT.

While each system has CDNs with varying power limitations. It is common for both ac and dc capabilities to be present. The voltage and current of the EUT must be within these limits prior to testing, or the system will be damaged. There are several power CDNs on the market that can deliver up to 200 amps.

Transformer in transient test setup
Testing with a power supply
Although it is not always necessary, some manufacturers advise using an isolation transformer. They do this to limit any residual current and make sure that any circuit breakers are tripped. The isolation transformer is positioned between the mains power supply and the EUT supply input.

The electricity entering the CDN will be used to power the EUT/DUT. If the related equipment is powered by anything other than ordinary mains power, a source will be required to allow the EUT to operate. When using an external supply, keep in mind that the CDN’s ac capabilities may differ from the dc. So check values for both before conducting the test.

Testing via direct out
To test data and communication ports, electrical fast transient (EFT) testing is frequently carried out using a capacitive coupling clamp. The straight out can also be used for surge testing. It is typically located on the rear of most test systems. The direct pulse output cannot be linked to a CDN or utilized for power line testing. Any power-on testing must be done through the CDN. Or the linked equipment may be damaged.

Selecting Testing Criteria
The front panel or the relevant software can be used to choose the testing criteria. As seen on the IMU-mgs display to the right, the front panel of the generators frequently shows which modules or capabilities are installed. Many of the most common standard test routines are also accessible via the front panel display of many systems. They provide an effective solution for a wide range of applications.

Testing using software
Test systems usually contain proprietary software. This improves the automation and programmability of the testing process. It becomes accessible either at the time the generator is purchased or at a later period. Some systems come with more “basic” partner software. This allows for the most common tests to be tested remotely for free.

The EM test nx5 video includes the following:
• Connections to the front and rear of the unit
• Methods for connecting to the EUT/DUT
• Adjusting testing criteria via the display
• CCL connections to the system
• Coupling path selection Axis system
• Line coupling path

The two methods for exposing EUT/DUT to transients are common-mode and differential mode. Following the 2nd edition of IEC 61000-4-4:2006, the use of electrical fast transient pulses (eft) is only required in common mode. Combination wave surges, on the other hand, are often examined using both differential and common-mode methods. These coupling arrangements are most often performed in accordance with IEC or ANSI procedures. Here many test systems support both.

Common setup requirements for transient immunity tests
The IEC 61000-4-4 specifications for tabletop equipment from the EM test nx5 user handbook are used to produce the general setup for electrical fast transients. Even though the related configuration is developed for eft testing. Similar test settings can be utilized for a variety of transient tests. Referencing the specific standard is suggested for compliance. Nx5 platform burst eft configuration.
• Grp
• Transient generator
• Capacitive coupling clamp
• Insulating support
• Grounding strap/cable
• The ground reference plane is usually made of ALUMINIUM, copper, brass, or other common metals. Different metals will be used depending on the application or necessity due to their properties. (For example, the malleability of metal, etc.) Several tests for these aircraft will frequently use the same metal(s).
• Grounding strap/cable – this is an extremely important safety element to have while undertaking this type of testing. They are often included with the generator. Although they can also be bought separately for particular sizing requirements.

Pulse/waveform verification
The waveforms of numerous EMI pulses from a transient generator are regularly inspected. This is to ensure that it is running properly and that the pulses are within specifications. In most cases, this is done by studying the voltage (open circuit) or current (closed circuit) waveforms. Several pieces of measurement equipment are required. However the conformity assessment industry has just produced trans-sense. It is designed for rapid pre-check of several typical transient pulses.

Waveform of current
Verification of current waveforms with a probe
Combination wave surge current waveforms are closed circuit confirmed across multiple CDN lines. During this verification, no EUT power is used; otherwise, damage to the measurement equipment is possible. An oscilloscope, a current monitoring probe, and an attenuator are frequently required for verification. Although calibrated measurement equipment is commonly used for ISO 17025 calibrations. It is not always necessary for functional verification.

Waveform of voltage
Setup of voltage waveform verification with axos5 test system
A voltage differential probe is used to compare voltage waveform values to those defined in a previous calibration. Combination wave surges, electrical fast transients, and other voltage-based EMI events are used to accomplish this. The CAL test ct3681 is the most often used differential probe, with capacities of up to 7kv. There are also further probes on the market with capabilities greater than 15kv.

How to choose a transient generator determine testing requirements
The first step in acquiring (or renting) a transient generator is to describe testing needs precisely. If the standard or parameters are not correctly identified. It will be difficult to obtain compatible equipment.

Common transient test system capabilities
While this step may sound simple, it might save you a lot of trouble later on. Consider which testing capabilities are necessary and to what extent. As well as what may be required in the future. The specifications for a specific type of product are frequently defined directly in the underlying test standard. This allows the selection of a generator to meet those needs.

Many test systems on the market today come in a range of configurations that allow for the blending of various capabilities to fulfil individual customer requirements. Keep in mind that, unlike many other types of test equipment, these pulse generators normally do not provide key code access for further features.

Coupling decoupling networks (CDNs)
Coupling decoupling networks (CDNs) are devices that allow disturbances to be introduced into related EUT/DUT power cabling and then removed prior to auxiliary equipment. This injection or coupling devices are classified according to the kind of port under test and the related EMI pulse or transient. Many immunity test systems on the market today contain built-in CDNs, such as the EMC partner IMU-mgs.

Calibrations
The two basic types of calibrations offered are ISO 17025 and NIST traceable calibrations. Many calibration labs and some manufacturers offer these services. A manufacturer calibration is a good option for companies who wish to limit the number of vendors or have the team involved in repairing or manufacturing perform the calibrations. Many calibration labs now do onsite calibrations, ensuring that the equipment is not damaged during transit and reducing downtime.

FAQs
What exactly is a transient generator?
Transient generators, a type of electrical test apparatus, are used by engineers to perform spike susceptibility testing. When powered up, transient generators produce brief pulses. Industry standards mandate that engineers evaluate interference voltages on specific systems and pieces of equipment.

What requirements does ISO 7637-2 place on pulse generators?
Iso 7637-2 pulse 1: It is a simulation of transients stimulated by supply detachment from inductive loads. It is applicable to a DUT if directly linked in parallel with an inductive load, as in an automobile. Pulse ISO 7637-2 2a: Simulates transients caused by a sudden stoppage of currents in a device connected in parallel with the DUT due to wiring harness inductances. ISO 7637-2 pulse 3a/3b: This is caused by switching processes. The properties of this pulse are controlled by the wiring harness’s dispersed capacitance and inductance.

What exactly is a transient surge simulator in an automobile?
Simulator for testing automotive electronics immunity that reproduces numerous transient surge events observed in automobiles and outlined in the international standard ISO-7637-2.

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