FAQs High Voltage Power & Safety

Why are corona rings/toroids/balls used on high voltage power supplies?

Spellman makes high voltage DC power supplies with output voltage up to and beyond 360kV. At these extreme high voltages the physical geometry of the surfaces at high voltage becomes a critical consideration with respects to suppressing the generation of corona. Corona is a luminous, audible discharge that occurs when there is an excessive localized E-Field gradient upon an object that causes the ionization and possible electrical breakdown of the air adjacent to this point. Effective corona suppression is a crucial factor to take into account when designing high voltage power supplies.

The large diameter, smooth spherical shapes of corona rings/toroids/balls helps to control the local E-Field, thereby suppressing the generation of corona. As the output voltage increases the diameter of the required corona ring/toroid/ball must also increase to obtain effective corona suppression. Spellman has decades of experience in corona suppression techniques, uses sophisticated E-Field modeling software and partial discharge measurement equipment to assure our power supplies designs provide effective corona suppression, regardless of output voltage.