12 volt cfl's

dolcesails
dolcesails Registered Users Posts: 11 ✭✭
I bought a couple of them on e-bay 13 watt cfl - 12 volt, on the volt meter set on dc amps it showed 1 amp, puts out enough lite to lite a room, led lite use less energy but I don't think they put out enough lite to even read by..............what are your thoughts pros and cons.

Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: 12 volt cfl's

    concur, unless they have improved the < 3 watt LEDs in MR 16 style (which are a focussed beam, are just good enough to find your way in the dark to the fridge or ? in pitch black
     
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    Re: 12 volt cfl's

    No personal experience with 12 volt CFL, but find most 12 volt LEDs to be VERY dependent on voltage when it comes to brightness. The worst one I have is actually a 12 volt "track light bulb", and at 12 volts the light output is so low that even in a dark room you could miss it being on. During the day however, when the PV brings the voltage up to 14.5, it becomes a great little light - - - when we don't need it.
  • john p
    john p Solar Expert Posts: 814 ✭✭✭
    Re: 12 volt cfl's

    12V LED MR16s 3w by Cree are excellent light output and if you get the wide angle ones spread is ok. We use 8 of them for house and yard perimeter security lighting. 3 of them light our back yard a size of 13m x 15 aprox (42ft x 48ft) and you could sit and read a newspaper anywhere.
    Every 12v x 10w CFL I have ever used had 2 serious problems. First, very short life .Two, very low light output compared to same wattage 240v version.

    6 of my MR 16 x12v have now done in excess of 30,000 hrs and appear as bright as when new.
  • RandomJoe
    RandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: 12 volt cfl's

    I briefly considered 12V CFLs, but quickly decided against them. Ridiculously expensive compared to standard 120V models, not very bright, and the ones I had died fairly quickly - further exacerbating the cost issue. I opted to use 120V CFLs with an inverter, much simpler. The bulbs are also far more readily available to me, at any local store, whereas the 12V versions must be shipped in.

    12V LEDs are getting better, but I find the color quality of the 120V versions to be far superior. I use a number of 12V LEDs, though mostly just for task illumination in inconvenient locations. A small battery and LED drop-light can light some dark corner of the attic like the sun! :cool: But the light quality is lousy for regular use in the house. There, again, I use 120V bulbs on an inverter.

    I do have a couple 12V fluorescent fixtures that work well - though they don't see a lot of use so can't say about longevity. One is a 16W (2 8W tubes) RV fixture, about a foot long. Good light for a work area or small room. I also put two 12V ballasts into a 4-foot 2-tube F32T8 fixture. Each bulb/ballast draws 2.5A, and they light up VERY well, I can't tell much difference from the 120V ballasts. Of course the ballasts I used were quite pricey, so not sure that's a very sensible option.
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: 12 volt cfl's

    12v CFL work almost identical to 120v AC CFL. 120 vac CFL rectify to D.C. around 160 vdc and have a push-pull chopper inverter that works at 25kHz to 40 KHz. This high frequency is fed into an inductive ballast based on high chopping frequency reactance for the ballast. Because of the high frequency the ballast inductor is a physically small ferrite inductor (compared to the big 60 Hz ballast of olden days).

    12vdc CFL have a DC-DC boost inverter that take the 12vdc up to about 160 vdc and then chop and ballast just like the 120vac version.

    LED light are very much dependent on the regulation drive circuitry. Just putting a series resistor from 12vdc is very cheap and power wasteful approach. You need a power efficient inverter that supplies a constant current source to LED. This is done on high priced LED lights.