In the dark, the photocell’s resistance is high, and the voltage divider’s output is sufficient to charge the capacitor C2 quickly, achieve breakover voltage of the diac, turn the triac on, and bring the lamp to full brightness.
I was just giving an example of a CFL that turns on instantly. Your article did not specify the unusually high light levels that you required and that this was the reason to select specific CFL, which apparently start slow. What kind of work is done in your shop that requires such high light levels?
I'm sure that there are other solutions. I needed floodlights of 1000 lumens or more and total wattage of 200 or less. There aren't many CFLs available in that category. I suppose there may be some that brighten faster.
GE actually makes a hybrid lamp with a halogen bulb in the center of a CFL that works much like this. But not in a floodlamp configuration, and they are more costly.
How about testing a few CFLs until you find the ones that turn on instantly?
I have seen s-l-o-w starting CFLs and I have seen fluorescents with electronic controllers that start full brightness immediately when turned on. I even have one as a flashlight / emergency light that sits plugged into AC and the same moment that the grid power goes out (which is too often here) the light comes on full brightness. The lamp has no marking but it is a folded CFL tube of an estimated 10-15W, so very bright floodlight, operated from a built-in 6V sealed lead-acid battery by a small inverter board that also keeps the battery charged.
I have always converted every house I moved into since the CFLs became popular to as much CFL-only as possible and saved tons of money on power bills, even including the initial purchase of the lamps. I started to add some LED into the mix since a year, but still find too many failures from cheap Chinese manufacturing and bad design.
Not saying that this gadget is not useful, but it feels a bit like a kludge - an unnecessary complicated solution. But maybe this was simpler than buying new / the right type CLF, I don't know.
Good to see someone sat down to build one, but this already exists... It's called a Quartz restrike, and is used where you need light when you have metal halide or other arc discharge lamps that may go out due to frequent poewr fluctuations.
For the case of the homeowner though, wouldn't it just be cheaper to just use the incandescent and turn it down?
Wow, @Dick, that is really nifty! We have CFLs in the restrooms of our new science building. They are on a motion-sensor switch / timer that energizes them on entry. Not that you need lots of light for detailed work, but the room does take around 40 seconds to turn from an eerie yellow to solar white. The biggest problem is that the motion sensor cannot see down into the stalls... so if you bring along reading material, you only have about 3 minutes before you have to use your cell phone as a flashlight. -- but I guess that is another problem all together. Nice work! =]
Having just moved into a new house that is "challenged" in terms of adequate outlets/lighting, I can totally empathize with his situation and could use some of that creativity in my new home, albeit with a slightly sleeker, and less obtrusive asthetic design (no offense, Dick).
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