Traditional Ballast Technology
Most magnetic ballasts use a metal or plastic canister known as a capacitor as part of the regulating system. These ballasts are heavy, rugged, and built-to-last for many years in harsh weather conditions.
Latest Ballast Technology
For years, the terms Electronic and Digital were interchangeable when talking about ballasts for grow lighting. As the technology and the indoor growing industry has changed, so has the differences between these terms.
Electronic ballasts use semiconductors and microchips to provide the high voltage and wattage required by HID lamps.
The inside of an electronic ballast looks very similar to the inside of a computer. One or more circuit boards house mini capacitors and mini wire wound magnetic transformers. The use of these circuit boards allows for light weight and produces less heat than a magnetic ballast.
Most, if not all, electronic ballasts today are not digital even though they may be marketed that way. Digital would imply that the ballasts would have a microprocessor inside.