Pearson Electronics, Inc. High Voltage Pulse Transformer

Pearson Electronics specializes in the design of high voltage pulse transformers. These transformers employ open construction and are intended to be used in high voltage insulating oil. Pulse output voltages range from 100kV to 500kV with pulse lengths ranging from 0.25 to 50 microseconds. Inquiries for pulse transformers can be made by completing the pulse transformer requirement sheet. Pearson pulse transformers feature a minimum of solid insulation in regions of high electric field. This type of construction prevents damage to the transformer by accidental flashovers due either to poor oil or to overvoltages beyond the typical 50 to 100% safety factor built into the transformer. The intentional weakest region is between the high voltage corona ring and the core. These are metal surfaces and flashovers between them have negligible effect on the surfaces for the energies involved in even the highest power line-type pulsers. In spite of the voltage stand-off safety factor built into the transformer, and the feature of being able to withstand reasonable flashovers without damage, there are still occasional cases of damaged transformers. On inspection these units invariably show that they have been operated in oil that was dirty or there have been enormous over-voltages, sometimes approaching a million volts for a unit rated at a small fraction of this value. It is hoped that the following notes will help the user avoid these difficulties. The necessity for good oil is generally accepted, but often the specific precautions necessary are not understood. Pulse modulator malfunction is not so generally appreciated as an important and frequent cause of accidental overvoltages. In fact, it is often a major source of trouble. Over-voltages can be difficult to detect and the causes difficult to diagnose.