Well, these are strange indeed… FEIT Electric makes these 12 volt CFL twist light bulbs. Put them in a socket, apply 12v, and they light up, right?
Well, they’re… uh.. picky.
If the power does not come on INSTANTLY, like, from 0v to at least 11v in a few milliseconds, the bulb fails to light and something inside the ballast trips out. My guess would be a PTC (polyfuse). You have to wait a couple minutes then try again — and hope your power holds up THIS time… A voltage brownout that causes the bulb to dim out seems to also trigger this.
This could be trouble on a lighting controller that doesn’t turn them on instantly, or in vehicles where the power may dip due to cranking the engine, etc…
I think I’m definitely going to say that LED bulbs would be preferable to these. I mean, they work, but that behavior is just so weird!