The type of ballast can vary. Ballasts are used to control the power sent to the UV lamps. Electronic ballasts use a series of induction coils whereas Magnetic ballasts use one.
Beds with a magnetic ballast may have a minimal flicker or hum whereas this is almost non-existent a bed with electronic ballasts. UV equipment is designed to contain the lamps, starters and ballasts behind a specifically designed acrylic composite that allows UV rays to work effectively. Modern ballasts work at a much higher frequency, allowing for more efficient use of power.