For a long time, I've been trying to get the most bang for buck out of standard TV Flybacks. Recently, I've purchased 5 brand new (maybe they're new old stock by now) Line Output Transformers for CRT TVs. They were less that 10$ including shipping. I decided to build a true flyback converter to power them way past their initial design requirements. As opposed to the ZVS drivers, this driver is a tad more complicated but offers adjustable power output, frequency tuning for the transformer and runs them in actual flyback mode, meaning the risk of saturating cores and blowing up silicon is much much lower.