Difference between between magnetic, electronic and digital ballasts

Im no expert but my buddy used to grow and i think they're just advancements in the same technology.
Magnetic ones tend to be lunky and large and run EITHER HPS or MH bulbs. Electronics have a switch and can run both it also transfers current better provideing a longer life span but are still alittle lunky.
Digital ballasts automatically determine the type of bulb your using and fire it HPS or MH with no switch or altering.

If your not going to use Metal Halide bulbs get the cheapest ballast you can find. If you want to veg with HM and flower with HPS it is DEFINATELY worth it to get the digital ballast.

Magnetic-good
electronic-better
digital-best

*Keep in mind they make electronic ones that DO NOT switch make sure if you go that route that your buying the one you need.

**Do NOT buy a light with an 'internal' ballast which is a hood and reflector with the ballast attached. They're too heavy to safely hang and they get VERY hot.

Digital and Electronic ballasts are the same thing. They are the future of growing. They are solid state. They are basically setup like a car amp inside and out. They are a little more energy efficient(a couple dollars a month), and they cost a lot more for the most part. Unless you buy a really cheap one, and cheap = bad in this case. They have also not been as reliable, though better ones are out in the market now, but they cost a lot more than a comparable magnetic ballast. If they aren't under warranty and they stop working, you will just throw them away.

Magnetic ballasts are old school technology. They are cheaper, they run a little hotter, they are heavier, and they hum. (they aren't as loud as a fish air pump on average) They are very reliable, even the cheap ones, and you can repair them if they are not under warranty very cheaply. You can also rebuild a magnetic ballast like new in about 15 minutes and very cheaply: $50 400w, $75 600w, $100 1000w