If you think plugging a flourescent lamp into a light socket to replace the incandescent bulb is a thing of recent years, take a look at this:
It's a 20W fluro light that plugs into a bayonet socket. I bought this unit in 1981 but had seen them since the late 1970's. The construction is the most interesting thing. It's basically a plastic tube with a bayonet plug mounted in the centre and the control gear inside. That's the interesting part...as you could imagine a heavy iron cored choke hanging from a bayonet light socket could be a bit heavy. So they use a resistor...
You can see how it's constructed through the hole left by the bits of broken plastic (the UV is to thank for that). It's just like a radiator element except the tube is glass instead of quartz and the resistance is a higher value (about 500 ohms). It's the first commercially made flourescent lamp I've seen using a resistor. Needless to say, efficiency isn't that great, drawing .4A at 240V (about 100W). The other thing is that the tube used in it needs to be one with a starting strip, as there is no inductive kick back to fire the tube when the starter opens. I don't think the makers ever envisaged it, but it will work on DC mains.
They're sold here and used for places like kitchens, some table lamps....etc.
It is essntially a version of compact fluorescent lamp. Probably better since when the ring goes out, all you do is replace the ring, not the ballast.
Some years back I installed a screw-in ceiling bulb fixture in my mom's kitchen to replace the non-working fluorecent fixture (this was on a weekend and was all I had available and all I could afford at the time). I screwed one of these fluorescent rings into it.
Some time last year, during one of their inspections, the housing authority came and replaced it with a proper fluorescent lamp.
#144888 - 01/30/0608:03 PMRe: Before Compact Fluoros
Must be a little bit of heat generated in theat 500 Ohms resistor.
. It does get fairly warm but the heat is spread out over the 2' length. It calculates to about 73W. However, if the starter shorts out and the lamp is left on it would be about 115W. This example was made in Australia by a small appliance company in Melbourne by the name of 'Companion'. They call this light a 'Flurinstant'. I'm pretty sure it was originally a UK design however. The instruction manual also mentioned a 40W and double 20W version. Many years ago I remember seeing homemade versions of this in a car park in an old part of Sydney. However, an incandescent bulb was used as the current limiter (240V 100W gives the right current for a 20W tube) and they were all assembled hanging together with bits of wire plugged into the BC sockets. One day I'll reproduce one.
#144889 - 01/31/0604:47 AMRe: Before Compact Fluoros