Using incandescent bulbs to compensate for a slow start cfl

[Dick], like most of us, likes some pretty strong light in his workshop. He’s using CFL flood lamps to save a little energy. Unfortunately, he found that they gradually become brighter instead of that instant light he was accustomed to with his previous incandescent bulbs.

Not wanting to wait around for the lights to reach full power, but still wanting to save electricity, he devised a plan . He would install an incandescent bulb along side the others and fade it out slowly as the others became brighter. He acknowledges that he could have just put a 5 minute timer on it, but the transition would be abrupt and unpleasant. Instead, he built a circuit to get the exact result he wanted.

Just so you don’t miss it, the actual build is available to download at a link toward the bottom of the page.

[via HackedGadgets]

20 thoughts on “Using incandescent bulbs to compensate for a slow start cfl

    1. Some are better than others at their initial brightness. However, generally CFLs are a little dimmer than their incandescent brethren. You grow accustomed to it over time though, I hardly notice anymore.

      1. i think this may be due to the combination of mercury vapor and pressure of the envelope.

        stadium lights that take a several thousand volt startup charge start off dim and get brighter and they are high pressure i think several psi.

        i have seen somewhere the xenon lamps used in projectors and the big lights like used to make the memorial beams on ground 0 on march of 2002 i think run close to 200 psi.

        a way to get a bulb on instantly would be to replace the inverter with one from a scanner ccfl lamp.

        ccfl uses higher voltage to make them come on instantly.

        cfl i think runs on less than 1000 volts and has to be warmed by little heater at each end of the spiral tube.

    2. The IKEA bulb in my livingroom lamp starts like a night-light but eventually ramps up to a nice room-filling brigness.

    3. I read that they can make them start quickly but it would reduce the lifetime and/or require a lot of cooling and copper, which is expensive for something that only is needed during startup – and which the consumer generally isn’t going to pay for unless they are one of the few that specifically look for it and have plenty of cash.

      Things are getting better though over time, they tweak and improve.

      1. Do they need to actually warm up then?

        So, couldn’t one build a heating element that helps warm them at start?

    4. Cheap CFLs are cold cathode lamps. Basically a neon tube. They have terrible start up times but are very cheap to make. This is what you find at the bargain bin at home depot.

      The good CFLs are programmed start. The internal ballast warms the filaments and ignites the lamps much like sandard rapid start or program start linear fluorescent lamps. These come on closer to full brightness.

      So, buy good lamps (Philips) and you won’t have to mess around with a hack like this.

  1. It depends on the lamp: got some from the Ikea and they take about half an eternity to give some light; replaced them with lamps from my local supermarket and they go from 0 to 90% in a few seconds; they take a bit longer to emit the full 100%.

    I’ve got 4 35W old-school TL-lights in my workspace; lots of light and they aren’t visibly dimmer when they start up.

  2. Orientation also matters. An upside down or sideways bulb will take longer to reach maximum brightness than an upright bulb.

    Something to do with the tiny amount of mercury vapor condensing on the electrodes permitting it to vaporize faster.

  3. Somehow all the standard, cheapest 60W replacement CFLs I have bought the last few years light up to what looks like full brightness just about instantly(even upside down). I have seen some take ages, weird that many cheap ones are so fast now.

  4. Temperature matters too. Cold bulbs can start quite slowly. I wonder if Dick’s garage is heated?

    And I’m not sure if it was just a bad brand, but the only time I’ve tried CFL floodlights, they were the slowest starting CFLs I’ve ever seen.

    Usually, the first couple of minutes in any shop are spent on preparatory tasks that don’t require much light. So I wonder if this is really a problem in need of solving. But if Dick considers it so, then he’s certainly solved it quite cleverly.

  5. FYI – GE produces a hybrid bulb that’s got a halogen lamp and a CFL in the same glass envelope. It operates like this project, both turn on at power on, and the halogen turns off after a minute or so, when the CFL is at full brightness. You can get up to 100W equivalent. You can get them for about $6-10 US each.

    1. I saw a review about these in a magazine a while back. At the time, they were listed at $30 each or so, but I wouldn’t be surprised if they’ve dropped that much. They didn’t have too many complaints other than the price, either.

  6. I have some 100 watt equivalent CFL GE bulbs in my living room, they are great bulbs that have lasted for about 4 years so far. But they start very dim (I would say about 40 percent) and ramp to full brightness after about 3 minutes. The bulb that microHacks is talking about would be a good compromise between energy savings and full brightness on power up.

  7. this is my take on the cfl warming up thing:

    it’s the circuit that determines the initial brightness, as well as a possible thermostat to control this action.

    why do they do this?
    the faster you activate 100% power, the faster it wears out, for two reasons;
    1) the gas, gas pressure, mecuryVSothergases, and mercury deposit
    2) filiments often wear unevenly, warming them up slowly increases life dramaticaly
    (for BOTH incandesant AND flourecent)
    3) picky people would rather spend more on bulbs per year for 99% switchon instead of 90% or 50%

    4) this guy has it best, save the switchon damage for the cheapo 1$ bulb, and buy the (expensive) LONG LASTING (slow startup) cfl’s,,, so they *actually* last the quoted time!

    PS: personaly i would rather keep the cfl’s switched off for about 1 minute(then the special warmup procedure here), cuz we all flick them on for 1 minute then off, regardless of if we know its bad for the cfl’s.

  8. Great project! I like the above commenter’s idea to leave the CFL off for 1 minute to avoid unnecessary startup for quick on/off scenarios. Another potential improvement could be a “soft-start” 1-second ramp-up for the incandescent bulb to help preserve its filament.

    Thanks for sharing!

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