The component of a fluorescent light that provides the starting voltage and operating current.
Conventional ballasts provide current using electromagnetic means. They are typically large in size and consist of coils of copper wire wound around an iron core. Light flicker and audible hum are frequent problems with this type of ballast.
High frequency ballasts are small electronic devices, operating at 25,000 Hz or greater; because they operate beyond the range of hearing they do not hum. The electronic starting mechanism is more efficient than a conventional ballast.