In order to protect critical electronic equipment against damped sine transient currents induced into its cables due to transient electromagnetic fields, switching phenomena, platform resonances, etc., a proper measure should be taken.
In any major equipment, there must be several individual units (LRUs), which are interconnected by cable harnesses in varying lengths. When such equipment is used in severe electromagnetic (EM) environment, the loops consisting of the shields of cable harnesses, the grounded chasses of LRUs at the two ends and the ground path provide coupling with the interfering fields. The induced voltages, particularly due to the current in the cable shields, can cause temporary upset or permanent damage to the LRUs connected at either end of the cable harnesses.
To ensure satisfactory performance of the LRUs under such conditions, it is necessary to simulate appropriate conditions in a laboratory and conduct an evaluation.
In order to protect the critical electronic equipment against damped sine transient currents, Jong Hak Chol, a section head at the Faculty of Electrical Engineering, generated and induced the necessary damped sine currents into the cables of the electromagnetic compatibility test (EMCT) equipment in the laboratory. Then he developed a test equipment CS116 of Standard 461E/F and measured other factors using this equipment.
Many approaches using LC discharge have been investigated as a general way of producing damped sine current waves, but those need tiny amount of inductance and capacitance and they tend to cause wave distortion and power loss. Especially, demanding value of inductance for building a damped sine wave generator for 30MHz and 100MHz are around 5 to 14nH.
Thus, he designed and manufactured a damped sine wave generator with small inductance and capacitance, and conducted some experiments to verify its output.
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