low wattage LED light bulbs

Discussion in 'Electronics & Electrics' started by xc351, Feb 5, 2019.

  1. xc351

    xc351 Member

    Joined:
    Dec 30, 2005
    Messages:
    2,334
    Peoples, im looking for some LED light globes which will be left on 24/7 all i can seem to find is 5.5/6w. Does anyone have any better options ideally 2w or so.

    Yes im fully aware its next to no difference power wise but its for the external just to help find the key hole.

    4w x 24 = 96w
    96w x 365 = 35040 /1000 = 350.4kw/h
    350.4 x $.29 = $10.16 extra cost per year

    Also you will find a sensor will prolly use as much power so its just as cheap to run it 24/7
     
  2. Symon

    Symon (Plugging your Socket)

    Joined:
    Apr 17, 2002
    Messages:
    4,410
    Location:
    Santiago, Chile
    You can get 3W MR16 globes on ebay.
     
  3. OP
    OP
    xc351

    xc351 Member

    Joined:
    Dec 30, 2005
    Messages:
    2,334
    Sorry i should say i need EC27 (just standard screw in bulbs) im not horribly keen on chinease ebay crud as i've killed numerous cheap LED bulbs before
     
  4. Sunder

    Sunder Member

    Joined:
    Apr 26, 2012
    Messages:
    2,992
    Full size E27? Yeah, you're gonna have difficulties. Are you even sure 2W is bright enough? I bought 4 x 3W E14 (Small edison screw) candle shaped for a stairwell light. 4 of them together is only just enough to walk by. (There is some dimming from the light fitting, and the fact it's a pendant light over the stairs, but still) You wouldn't want to be reading anything on the stair well.

    Remember a 2W 240v light is not going to be like a 2W flashlight. There's issues of directionality and efficiency as well. The light has to step down the 240v and rectify it to DC for the LED to use, while a flashlight only has to regulate it very close to the battery voltage anyway. I have a 2W night light that basically is enough to to see which direction to walk. You can't even make out the colour of the toothbrushes 30cm away from it. Part of that is obviously the sensor, but I think that's the kind of brightness you're talking about.
     
  5. OP
    OP
    xc351

    xc351 Member

    Joined:
    Dec 30, 2005
    Messages:
    2,334
    I’ve bought 2w chinease bulbs before but they were chinease crud (were for my mothers crystal lamp (she hated how powerful bulbs projected coloured light everyware). I’m sure my 2w leds will use more than that as they won’t take into account the step down voltage.

    In theory 2w leds will be the same. It’s just if it rates it as led power or total lamp power.

    Will it be enough It should be. My 7w incandescent salt lamp puts out more than enough light and it’s got to project light through the salt and it’s only a incandescent.
     
  6. slavewone

    slavewone Member

    Joined:
    Jul 9, 2002
    Messages:
    1,874
    Location:
    B.Mtns2774 Status:Unhappy
    For a similar situation, 4w was borderline in my situation. My issue is no one turns lights off and I’m always have to replace globes. Costs a fortune in power and globes.

    I tried a few things:

    A tiny stick on solar job. Doesn’t get enough sun, awful in winter, I think the batteries stayed too flat and gave up.

    A tiny stick on push on/off battery job. Always flat batteries. Kids gamed it.

    I now have a 6w e27 with a built in sensor (IR?) it comes on when background light is under 32 lux (and there is movement), does brilliant. It is currently in placebo because I got it recently.

    You might spend $20 in time to figure out if the actual cost of the 2w over the globes lifespan was better than a 6w. I probably paid 6x the price of a standard 6w LED for the inbuilt sensor, but I figure it is going to be on a fraction of the time compared to its predecessor so it’ll work when I need it and not be blown.
     
  7. OP
    OP
    xc351

    xc351 Member

    Joined:
    Dec 30, 2005
    Messages:
    2,334
    Yea you may find the sensor uses just as much power and you are better off running it 24/7

    Yea I can measure power easy enough.
     
  8. Rod911

    Rod911 Member

    Joined:
    Mar 7, 2002
    Messages:
    1,032
    Location:
    Melbourne
    Is it just you that needs the light, or do you have family members to consider? If it's just you, maybe a small torch like this. I've got one for each of my family members and it's really not noticeable in your keychain, but certainly handy when needed.
     
  9. Sunder

    Sunder Member

    Joined:
    Apr 26, 2012
    Messages:
    2,992
    In that case, I'd say your best bet is to get an E14->E27 adaptor like below, and look into 2-3W candles. As a passive device, it should draw no power.

    https://www.lightingsuperstore.com.au/product/233/es/ses-e14-adaptor/11571

    [​IMG]
     
  10. merlin13

    merlin13 Member

    Joined:
    Apr 12, 2003
    Messages:
    1,772
    Location:
    back in BrizVegas
    And that's a serious consideration of why you want 2 watters instead of the more readily available 4's?

    Then you want to run it 24/7. As you've looked into running costs down to the second decimal point have you factored in the shorter life expectancy running it 24/7?

    And all this is just to find a keyhole??

    Sorry, but for the ammount of dicking about you're looking at either get a suitable motion sensor, buy a torch, or find some serious luminous paint that'll cost nothing to run.
     
  11. Sunder

    Sunder Member

    Joined:
    Apr 26, 2012
    Messages:
    2,992
    Maybe he has a castle, with 3.1km of hallways that need to be lit by salt lamps every couple meters to keep the negative ion count high? That $10 adds up to tens of thousands a year.
     
  12. OP
    OP
    xc351

    xc351 Member

    Joined:
    Dec 30, 2005
    Messages:
    2,334
    A motion sensor would use a few what’s anyway.

    I’ll run a few, 5.5w is overkill for a general
    Light. Plus as there near windows I much rather a constant light then flicking lights on and off.

    As for killing them quickly I think it will prolong the life rather than Turing off/on numerous times. There is a 118 year light bulb that’s been on 24/7 sure it’s an incandescent. But proves the point
     
  13. Sunder

    Sunder Member

    Joined:
    Apr 26, 2012
    Messages:
    2,992
    Pretty sure the Centennial Light isn't long lasting because it is kept on. It's just a type of carbon filament instead of tungsten filament, that is extremely inefficient, but long lasting.
     
  14. RobRoySyd

    RobRoySyd Member

    Joined:
    Jan 24, 2008
    Messages:
    7,940
    Location:
    Sydney
    Kind of slipped a decimal in your calculations.
    35040 / 1000 = 35.04KWh so the extra cost is $1.02 per year.
    Hang on though, even that's not the extra cost, that's the total cost of running a 4W light. Compared to running a 2W lamp the extra cost would be $0.50 per year.

    If all you need is a light to see the keyhole then I've solved that problem. House has had a Friedland door bell since forever but the lamp in the push button kept failing and it hadn't been replaced for decades. So I fitted a full wave bridge rectifier across the PB switch contacts and used the DC from that to power 4 LEDs. Problem solved. Now I can find my way up the steps to the front door, see the keyhole and visitors know which door is the front. door.

    Energy wise it's a great solution. The transformer that Friedland supplied all those decades ago is very, very inefficient at rated output but has very low iron losses. The 4 LEDs use less than 1W, power factor is good as well although TBH I haven't measured it.
     
  15. greebs

    greebs Member

    Joined:
    Dec 30, 2001
    Messages:
    946
    Location:
    Melbourne
    A motion sensor will use less than 1W.
     

Share This Page