The most frequent cause of damage in industrial electronic systems is overvoltages, caused either by switching actions in the equipment itself or by atmospheric discharges such as lightning. If the interference source is in the same circuit as the electronic equipment, the transfer impedance is low and the impulse takes a current form. If the interference is from some external source, the transfer impedance will be higher and a voltage impulse results. To simulate both these conditions, a Combination Wave Generator (CWG) is designed to deliver a voltage impulse into an open circuit and a current impulse into a short circuit. This is also known as a “Hybrid” generator. Combination Wave Generators have a virtual impedance (open circuit voltage / short circuit
current) of 2 ohms.

Power network transients can be modified by the cable properties so that in a well
protected domestic or commercial environment, the impulse energy has an oscillatory
form. This is known as a “Ring wave”.

User Benefits The technical excellence and many unique features of combination and ring wave generators translate directly into benefits for the user: - Impulse repeatability pulse to pulse - Reproducible test results between locations - Automation reduces operator error - Combined coupler for all EMC power tests - Operator safety ensured - Reduced test time - ANSI coupling path compatible - Save operator time with the automated test routines and test report facility - Unparalleled reliability and system up-time Generators Two distinct generator types are available. Models up to 6kV with built-in automatic single phase CDNs intended for immunity testing (MIG0603INx), and generators with impulse amplitudes over 12kV (MIG1206, MIG1809, MIG2412, MIG1206-1P & 3P). Many of the generators include more than one impulse type, making them ideal for laboratory applications. All MIG0603INx versions include automatic peak synchronisation, which at the press of a button ensures the impulse is superimposed on the positive (90°) and negative (270°) peaks of the EUT power. In all cases, the most significant test parameters can all be programmed as fixed values on the instrument front panel, or using the ramp function to change parameters during a test. Impulse voltage level, synchronisation angle and polarity can all be programmed using this feature.