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Thread: Power usage when switching lights

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    Default Power usage when switching lights

    Hi all,

    Dumb question from me time, sorry, but it seems that there are a few people here who would likely know the answers.

    Back in my school days (more than half a century ago) I seem to remember our science lecturer saying that turning a light on uses more electricity than leaving the light on all day.

    Is this a load of tripe or was it true.?

    Also, do modern lights also use up more power when being switched on and off.?

    If so, which types should I use in my one bedroom mansion??

    TIA

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    For the purpose of your needs, the answer is no

    Some lighting sources do incur ignition currents that are slightly higher than running current.
    In a domestic situation, these are not amounts that make any discernible difference.

    Leaving your oven on for an extra 5min is far worse

    LED is a popular choice for lighting sources now
    240v no external driver.

    I'm sure your modem, computer, phone charger, toaster and kettle all draw more power than any lighting concerns
    Last edited by ol' boy; 23-05-20 at 04:24 PM.
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    Quote Originally Posted by Ma_Baker View Post
    Hi all,

    Back in my school days (more than half a century ago) I seem to remember our science lecturer saying that turning a light on uses more electricity than leaving the light on all day.

    Is this a load of tripe or was it true.?


    Luv and kisses as always



    Cheers
    Interesting that I still hear that quite often, that must have been some popular teacher.
    Old fashioned light bulbs drain more power for a split second until they warm up but just leaving it on for 10 seconds would use far more energy than that.

    Start up current (as this is called) for modern LED light bulbs is even far less and can be ignored but the main advantage is very little power consumption overall (up to 8x less) and very long life.
    Go LED lamps.

    However they do need extra airflow for heat dissipation. Sometimes simply replacing an old incandescent light bulb with an LED bulb of similar design in an existing recessed or enclosed lamp fitting can lead to premature failure. They often first start to flicker before they fail.
    Last edited by Uncle Fester; 23-05-20 at 06:23 PM.
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    Quote Originally Posted by Ma_Baker View Post

    Back in my school days (more than half a century ago) I seem to remember our science lecturer saying that turning a light on uses more electricity than leaving the light on all day.

    Is this a load of tripe or was it true.?
    Complete and utter Twaddle!

    The powr surge for turning the light on would have to be insane to come near using the amount of power than leaving it burning all day would use. Things like Merc Vapour lamps have heaters in them to fire the main element but even they don't have huge surge, they just take a while to get up to full light output.
    Yes, the resistance in an incandecent bulb would be ghreater when cold than hot but that's a spilt second difference and one that amounts to watts not KW as would have to be for the
    On/ all day scenario.

    I have heard similar urban Myths about Trucks and trains, use less fuel to leave them idling than start them up. More complete and utter BS!
    In order for that to happen you would have to inject more fuel into the things to start them than they used Running. Does and can not happen. They get the same amount of fuel to start or fractionally more than they would running. You don't pour litres into the things to fire them up, that's just ignorant thinking there.
    When something isn't operating, it uses no fuel/ power. when it is running, it's using something. There may be reasons for keeping something running but saving power/ fuel is NOT one of them.

    Also, do modern lights also use up more power when being switched on and off.?
    No. again, in order for that to happen the surge power would have to be magnitudes more than the running power. Does not happen. You may be able to measure a watt or 2 as the circuitry in an LED or Fluro powers up but that power would be offset by seconds of run time not hours.

    If so, which types should I use in my one bedroom mansion??
    LED is Cheap to run, cheap to buy and gives an infinitely better light than those horrendous Compact flourecent things.
    I just bought a box of 30 12W Ceiling mount leds for $8. 20 ea with samsung Chips in them. They have a switch on the back where you can select from 3 Colour temps, 4,5 and 6000K. 4000 is like the old yellow incandescents, 6000 is pretty much white/ daylight. That's good in the kitchen, the 5000 is good most other places and the 4000 is good for a softer light in the lounge bedrooms. The kitchen is 70 SqM and I have 9 in there and the place is like a bright summers day. Put 3 in the hall way to replace the old 50W halogens and it's blinding in there now. 36w Vs 150 and the 36w is at least 5X brighter.

    I have 3x 4W Bulb type leds in coach lamps on the back Verandah. 12W in total and the verandah, 8x4M is well lit. Have some car type 20W Flood/ driving lights out the back on the eaves and they light the back yard brilliantly. Have no trouble throwing 100M up to the back fence.

    About this time last year the local bunnings were selling off a lot of Phillips and Osram LED globes in ES and Bayonet for 1 and $2. I bought a shipload, lifetime supply. Many of them were the higher wattage ones so I grabbed a good amount of them too. I have seen them clearing others as well so have a look there first and up the back on the specials/ Clearance rack. Their Downlights are pretty exy though, far better to go to an electrical wholesaler for those. I priced the bunnings ones a couple of weeks ago and they had 7W for more than I got the good 12W. I could have got 13w at the wholesaler but they were nearly twice the price and I'm certainly not thinking the 12w's aren't bright enough that's for sure!

    LED is so bright, efficient, cheap and has such good light quality now you can't go past it.

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    As Fester has stated, the surge current will be more than compensated for by leaving the light on for a few seconds. So, IOW, turn the Bl***y thing off when you leave the room!
    I'm out of my mind, but feel free to leave a message...

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    This was actually referring to Florescent Lights. They have a high inrush current due to the starter / ballast set up.
    If you are continually turning these on and off, yes it is cheaper to leave them on.

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    How many times an hour would you have to turn them on an off and what would the tradeoff be in time on to break even?

    The inrush current is very brief and not that significant. Brief start up currents don't add up to a lot, it's the constant draw that matters.
    I'd suggest one would have to be turning them on and off every minute to make leaving them on the cheaper option.

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    Quote Originally Posted by Reschs View Post
    This was actually referring to Florescent Lights. They have a high inrush current due to the starter / ballast set up.
    If you are continually turning these on and off, yes it is cheaper to leave them on.
    yeah with capacitors to bring up the power factor they have a really short inrush - in the good old days when I was an apprentice - we changed out all of the fluoro lights for the high PF ones - basically they were about 50% to 60% efficient without the capacitors

    with modern LED's it makes no difference - they cost nothing to run even with the $$$$$$ per k/hr


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    Yes leds are the way to go these days, good light at high energy efficiency, reliable and easy to repair. They actually make it cost efficient to consider a few pv panels and battery for house lighting in some cases. The last lightbulbs we had were in the chicken brooders.

    My inrush issue was all these rotten switch mode wall warts and supplies in everything foisted on us by the greenies that come attached to everything. Not an issue so much those with mains install and 16amp trips but when you have small trips on the supply and you have enough of them when they all go on at once is a pain. Often they are no more efficient than a traffo especially with buck regs instead of linear, rarely properly isolated and give bites to damp skin, blow shit up when connecting things and seem to breed in the power points. Also if your prone to lightning like we are it goes straight through them and blows the lot.

    I wired the place with 5v USB outlets and 12v for everything else derived from buck regs on one central PSU system and rounded all the wall warts up and switched to led lights. Everything on one common, no bites, no blowups and vastly improved lightning lightning suppression at the main supply.

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    Quote Originally Posted by Reschs View Post
    This was actually referring to Florescent Lights. They have a high inrush current due to the starter / ballast set up.
    If you are continually turning these on and off, yes it is cheaper to leave them on.
    Mostly cheaper because the tubes and starter will last longer when not switched so often.
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    LED and CFL lights are awful. CFL lights have an atrocious failure rate and add mercury to landfills. The old FL tubes at least had a very long life span.

    LED lights synthesize the light spectrum using discrete wavelengths. They are bothersome to your eyes which are made to see sunlight which is a diffused light spectrum. There is a photochemical and electrical response in your retinas. Subjecting them to the same wavelengths for hours is fatiguing if not harmful.

    High wattage equivalence LED lights do generate some heat and they cannot survive in a sealed enclosure because their electronics cannot survive the moderate heat rise they produce on their own. CFL lamps fail for same reason in a sealed enclosure.

    I have exactly one CFL in my house, a huge one that was well made. I use it for a garage light. Small wattage LED lights are used but only outside where I expect longer lifespan and I don't look at them,

    Incandescent lamps are great. They may generate heat, but if you live in a northern climate where you are heating your home, that is not a bad thing. Incandescent lamps can be 100% recycled as there is nothing toxic in them.

    Incandescent lamps do have a high in rush current when switched on. That is the reason they fail upon turn on. If you have a dimmer switch, this reduces the current somewhat and they will last a long time.

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    Quote Originally Posted by Ma_Baker View Post

    Back in my school days (more than half a century ago) I seem to remember our science lecturer saying that turning a light on uses more electricity than leaving the light on all day.
    This speaks volumes about some of the morons that walk amongst us today
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    Quote Originally Posted by RFI-EMI-GUY View Post
    LED lights synthesize the light spectrum using discrete wavelengths. They are bothersome to your eyes which are made to see sunlight which is a diffused light spectrum. There is a photochemical and electrical response in your retinas.
    That is not correct. All light is made of a variety of colour temperatures which are Visible and non visible. the Human eye only sees a part of the electromagnetic spectrum as light. Led's like every other light source are made from varying wave length to combine and make an average over all Colour Temperature.
    Personally, I find Fluro light much more annoying and hard to deal with and it bring on headaches and a touch of light headedness when I go into shops and factories with endless banks of the things all glaring bright in their very abstract colour temperature as it is.

    LED in fact simulated a far closer to natural range of colour rather than the weird green- Blue even " Daylight" Fluros produce. The flicker rate of LEDS is much better than Fluros which can also lead to headaches etc when one is exposed to them for long periods.

    Subjecting them to the same wavelengths for hours is fatiguing if not harmful.
    There are various wavelengths of light in any light source including the sun which are averaged out. ANY light source has and average Colour temperature which is measured in Degrees Kelvin and unless the light was visibly cycling through a range of colours, any light source is going to be the same temp and have the same wave lengths. This is easy to prove with a camera by dialling in a fixed Colour temperature on the Colour balance and taking photos over a period of time. If the colour balance was shifting you'd see it in the pics but you don't with any light source. When colour balancing, you will also see how very yellow Incandescent is, how unnatural and horrible Fluro is and how Close to Daylight and natural LED is.

    If one is sensitive to colour Temperature, LED is far and away the most natural and Neutral artificial light source there is.


    They actually make it cost efficient to consider a few pv panels and battery for house lighting in some cases.
    Mrs wanted a Skylight in the new Kitchen. I have solar panels on the roof already and going to add more. I have heard too many horror stories about Skylights leaking plus the Cost was BS as well. I put a couple of old panels on the Verandah Roof and wired them to a couple of LED Lights that run all the time off the panels.
    They are actually more effective than having a skylight because early/ late in the day or in shitty weather, the panels still pick up enough light to drive the LEDS ( 2x190w Panels driving 2 x 12W LED's ) to give more light than a Skylight would by far.

    Panels cost Nothing, LEDS were $9.50 ea, only took a couple of 90mm holes bored in the ceiling instead of tearing up the roof with penetrations and didn't affect my existing panels. Mrs is very happy with the result and likes the fact the ceiling is clean and dosen't have a box hanging off to one side.

    At night these LED's come on with the rest of them but provide plenty of light in the darker areas during the day.

    I briefly looked at Solar & Battery's for the lights but it does not take much to work out as with anything, the second you involve batteries over Grid power, you are loosing not saving money. If you look at how Little LED lights Cost, the price of batteries, add in a Panel if you didn't have them etc, The amount of power the lights use as against the cost of the batteries simply does not add up.

    For waht I pay for power ( forgetting I'm well ahead on the solar at least 9 months of the year and maybe all of this year,) I would have to run my LED Lights 85 Hours ( for one) to cost me .30 Cents. Even if I have 20 at a time going which doesen't happen and then a number of them would be 4-6W globes not downlights,
    it woud Still be over 20 Hours to cost .30C.

    If a battery cost $100 to get something that would last, that's a long time to get your investment back not even taking into account the stuffing round.

    For some reason Lights are the first thing people think of with power use but I'd suggest in at least 95% of homes are probably one of the lowest users of power of all.
    In my house with a 12 ton AC that runs all winter for heating and all summer for cooling plus the biggest water heater they make, Lighting is well and truly at the bottom of the list for the power we go through which can easily be over 50KWh a day when it's hot or cold. The sump heater in the AC uses 1KWh a day just sitting there and I'm damn sure we don't come near that with lighting. Matter of fact, pretty sure with everything now being LED, every light in the place switched on at once wouldn't even pull near 1 Kw and we certainly don't have every light on for an hour at a time or more.

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    Quote Originally Posted by george65 View Post
    That is not correct. All light is made of a variety of colour temperatures which are Visible and non visible. the Human eye only sees a part of the electromagnetic spectrum as light. Led's like every other light source are made from varying wave length to combine and make an average over all Colour Temperature.
    Personally, I find Fluro light much more annoying and hard to deal with and it bring on headaches and a touch of light headedness when I go into shops and factories with endless banks of the things all glaring bright in their very abstract colour temperature as it is.

    LED in fact simulated a far closer to natural range of colour rather than the weird green- Blue even " Daylight" Fluros produce. The flicker rate of LEDS is much better than Fluros which can also lead to headaches etc when one is exposed to them for long periods.



    There are various wavelengths of light in any light source including the sun which are averaged out. ANY light source has and average Colour temperature which is measured in Degrees Kelvin and unless the light was visibly cycling through a range of colours, any light source is going to be the same temp and have the same wave lengths. This is easy to prove with a camera by dialling in a fixed Colour temperature on the Colour balance and taking photos over a period of time. If the colour balance was shifting you'd see it in the pics but you don't with any light source. When colour balancing, you will also see how very yellow Incandescent is, how unnatural and horrible Fluro is and how Close to Daylight and natural LED is.

    If one is sensitive to colour Temperature, LED is far and away the most natural and Neutral artificial light source there is.




    Mrs wanted a Skylight in the new Kitchen. I have solar panels on the roof already and going to add more. I have heard too many horror stories about Skylights leaking plus the Cost was BS as well. I put a couple of old panels on the Verandah Roof and wired them to a couple of LED Lights that run all the time off the panels.
    They are actually more effective than having a skylight because early/ late in the day or in shitty weather, the panels still pick up enough light to drive the LEDS ( 2x190w Panels driving 2 x 12W LED's ) to give more light than a Skylight would by far.

    Panels cost Nothing, LEDS were $9.50 ea, only took a couple of 90mm holes bored in the ceiling instead of tearing up the roof with penetrations and didn't affect my existing panels. Mrs is very happy with the result and likes the fact the ceiling is clean and dosen't have a box hanging off to one side.

    At night these LED's come on with the rest of them but provide plenty of light in the darker areas during the day.

    I briefly looked at Solar & Battery's for the lights but it does not take much to work out as with anything, the second you involve batteries over Grid power, you are loosing not saving money. If you look at how Little LED lights Cost, the price of batteries, add in a Panel if you didn't have them etc, The amount of power the lights use as against the cost of the batteries simply does not add up.

    For waht I pay for power ( forgetting I'm well ahead on the solar at least 9 months of the year and maybe all of this year,) I would have to run my LED Lights 85 Hours ( for one) to cost me .30 Cents. Even if I have 20 at a time going which doesen't happen and then a number of them would be 4-6W globes not downlights,
    it woud Still be over 20 Hours to cost .30C.

    If a battery cost $100 to get something that would last, that's a long time to get your investment back not even taking into account the stuffing round.

    For some reason Lights are the first thing people think of with power use but I'd suggest in at least 95% of homes are probably one of the lowest users of power of all.
    In my house with a 12 ton AC that runs all winter for heating and all summer for cooling plus the biggest water heater they make, Lighting is well and truly at the bottom of the list for the power we go through which can easily be over 50KWh a day when it's hot or cold. The sump heater in the AC uses 1KWh a day just sitting there and I'm damn sure we don't come near that with lighting. Matter of fact, pretty sure with everything now being LED, every light in the place switched on at once wouldn't even pull near 1 Kw and we certainly don't have every light on for an hour at a time or more.
    There is nothing I said that is false. LED lighting is a mix of very narrow discrete spectral lines. It is not at all like incandescent or sunlight which are a very wide spectral "noise" comprised of many wavelengths. You mention the electromagnetic spectrum. The sun emits energy all over the EM spectrum, and in fact is used by radio astronomers to calibrate receivers. An LED lamp emits only a small fraction of that spectrum and is "tuned" to mimick what the eye thinks is natural light. It is not natural light, and it is not good light for your eyes.

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    I remember my father drumming this urban myth in to us as kids, but only in relation to flourescent lights. A quick back of the envelope calculation shows that even if you assume the light consumes 10A for the first 10 seconds, there is no way it can be cheaper.

    As others have said, you should avoid turning them on and off all the time simply to avoid frequently replacing the starters and tubes.

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    Maybe Ma Baker will ask about keeping bottles of water in her fridge next or in the freezer to save on cycling start up costs?
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    Quote Originally Posted by george65 View Post

    I briefly looked at Solar & Battery's for the lights but it does not take much to work out as with anything, the second you involve batteries over Grid power, you are loosing not saving money.
    Exactly, we tried solar on our radio donga when it was basically the 100ft tower and primarily the 5gig link for the internet connection. The proper long life storage batteries were big bucks and I did not trust the claims of their lifetime so to begin with I put in a couple of big gel cells the same as in the UPS to see how it went, I knew the best was a few years life from these cells. But there are regular lightning strikes on the tower in the rainy season the network connection to it is fiber so the idea was 100% electrical mains isolation not cost of power for 24 hour operation.

    The calc was one days full sun runs the load and delivers a full change and a full charge was enough for 4 days load. It worked great till the rainy season came, then it was only good for a few hours into the first night. According to the weather station UV logging the daily count dropped 70% for a few months, an upgrade to work with those figures was totally unrealistic.

    There was no gain in doing a grid tieback with the panels here so we do the exactly same as Gorge65' skylight replacement, the panels supply daytime led lighting in the staircases to avoid a skylight installation we were considering and a few other dark places along with other dc load in the day when available with the mains picking up the slack overnight.


    But as for running that HVAC system mentioned, I would be looking at moving to a better climate! Here is 30°-32° by day down to 23° at 4AM all year, humidity is up at around 70% and follows the season so we have no need for heating or aircon so it allows an open fresh air lifestyle and also meaning our biggest steady load is lighting and the computers.

    So the led lights provide a great saving in our case.

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    Quote Originally Posted by ol' boy View Post
    Maybe Ma Baker will ask about keeping bottles of water in her fridge next or in the freezer to save on cycling start up costs?
    Thank you snarky for your valuable input to this thread
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    Simple calculus. The answer as you might have gathered form above posts is no.

    Even if there is special pleading with a high start up current we apply calculus to work it out.
    My mum used to say the old wives tale that flicking the lights on and off at the switch used more electricity. Nope.

    What we need to look a is power and energy and understand the difference.
    Lets for example say that a 100W light has twice the current draw for the first 50mS and then remains on for 1 second then off for 1 second.
    We end up with a (200x0.05) + (100x0.95) = 105Ws... 5% more power. But this neglects the 50% duty cycle.
    So it is ...
    [ (200x0.05) + (100x0.95) + (0x1) ] /2 = 52.5Ws.


    Quote Originally Posted by george65 View Post
    I have solar panels on the roof already and going to add more. I have heard too many horror stories about Skylights leaking plus the Cost was BS as well.
    Yep, I run solar sunlight in my kitchen. Oatley electronics actually made it a kit using old 80W CdTl solar panels.
    It runs 4 x 80W leds and they just glow while the sun shines.

    At night these LED's come on with the rest of them but provide plenty of light in the darker areas during the day.
    Mine done. they are hard wired and don't even have a switch.

    I briefly looked at Solar & Battery's for the lights but it does not take much to work out as with anything, the second you involve batteries over Grid power, you are loosing not saving money. If you look at how Little LED lights Cost, the price of batteries, add in a Panel if you didn't have them etc, The amount of power the lights use as against the cost of the batteries simply does not add up.
    Hahaha ... you sir, don't know where to shop
    Now I'm a bit more creative and resourceful than most people. I had a natural resource of batteries that I could round them up like feral goats.
    That resource is not what it used to be but I can still source batteries for practical prices and even at new retail price I can easily compete with grid connect power.
    My house runs on .... shit. I'm not sure. I must have about 100kWhr of batteries but I can easily live on 20kWhr.
    I run my bus on 20kW of batteries quite comfortably with 4kW of solar. I'm about to double that to 8kW with 20kWhr of batteries.

    So the 4kW of panels, batteries, cabling, purlins and 5kW inverter leaves me with change from $2000.
    What's your quarterly power bill George? If it is about $300, then this system pays for itself in under two years. Even if your batteries are end of life surplus you can recover that money in scrap metal price and save for some new batteries.
    And this is at the scale of running an entire house, not just a couple of LED lights.

    But yes, how you use electricity is a very big consideration in the return on your investment.


    In my house with a 12 ton AC that runs all winter for heating and all summer for cooling plus the biggest water heater they make, Lighting is well and truly at the bottom of the list for the power we go through which can easily be over 50KWh a day when it's hot or cold. The sump heater in the AC uses 1KWh a day just sitting there and I'm damn sure we don't come near that with lighting. Matter of fact, pretty sure with everything now being LED, every light in the place switched on at once wouldn't even pull near 1 Kw and we certainly don't have every light on for an hour at a time or more.
    Dang, now I know who's responsibly for global warming

    So I am of course resourceful and a bloody tight arse. The simplest thing anybody can do is get day time air conditioning in summer onto solar.
    That rally makes a big difference to a power bill.
    I'm always exploring solar powered air condition for things like an ammonia absorption system.
    Solar thermal heats an ammonia pipe which then dumps the heat into a higher water heat exchanger (hot water for the house) and then the ammonia trickles down and evapourates in another heat exchanger which blows cool air down into the house and the ammonia gas is then scavanged by water and taken back to the solar heating pipe. No different to how an old LPG or Kero fridge works. It's inefficient but it's free cooling.
    Of course when you consider it, running solar PV and a DC compressor or inverter system is just simpler.
    In any case, as long as you don't run it at night, it's free cooling. I'm still considering other thermal inertia system to try get better cooling on summer nights.

    At other end of system is heating. There's not a lot of sunlight for winter heating. Wood fire heating is the way to go. Especially if you know how to source wood on the cheap. There are several ways to do that but it's obviously harder in the city. I have a few friends in the suburbs who have no trouble running wood.
    In one case their house is just a little bigger than the wood can provide so they also run the air conditioner, but it uses much less power than it did before they put the wood fire in.

    Again, I'm still looking at some other thermal inertia system to help keep a house warm. I'm also looking at diesel heaters to see how well they perform an if they are worth scaling up.

    LED's well yes. I run all of my house lighting on off grid. I also run my bus lighting off grid. Both run on batteries at 12V.
    Though in my house, the 12V sown lights are in a shit place and I can't rewire them, so they run on 240VAC which is powered by a 24VDC 2kW inverter.
    I run multiple banks of 48/24/12V batteries. So rather than spend money on a particular voltage system, I just have that voltage available.
    24VDC because I bought a bot of broken 24V interters and repaired them. They cost me about $5 each so running a bank of batteries at that voltage saves money.

    I'm just flexible. If something doesn't work, I change it or try something else.
    Yes I am an agent of Satan, but my duties are largely ceremonial.

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    Quote Originally Posted by RFI-EMI-GUY View Post
    An LED lamp emits only a small fraction of that spectrum and is "tuned" to mimick what the eye thinks is natural light. It is not natural light, and it is not good light for your eyes.
    Ummm, I would have thought that was pretty obvious apart where you say it's not good light for your eyes. That is patently false.

    Why would you have an artificial light wasting energy spewing out IR and UV light when it is useless for the purpose of allowing humans to see? That would be dumb.
    The closer a light source is to natural the better so I fail to see where your position of not good light comes from while you are espousing other light sources that are further removed from Daylight Colour temperature as being better.

    Obviously no artificial Light source is natural light. Not Fluro, incandescent or LED. Again, LED is the closest in colour temp to natural light and the narrower the colour temp to 60000K the more efficient and the more natural the light source appears. Everything is balanced in colour to the normal response rate of the human eye at 6000oK and nothing other than led other than some filtered source produces that output other then LED. Given I have never seen 82C colour balancing filters on domestic incandescent lights and trying to balance the crappy Green/Blue and never the same spectral wave length of Fluro, not to mention the flicker, LED is far and away the better light.
    There is No reason to have any extraneous wave lengths that the eye can't see and in the case of UV is not only useless but harmful. The tighter the emissive radiation of a light source to it's desired Colour Temp, the better. Even merc arc Vapour and Halide lights are closer to neutral balance in many cases than Fluro and certainly incandescent Although you don't normally find them in households..... Other than mine! )

    The LED's I just put in can do 4000, 5000 or 6000o Colour temp which is pretty much incandescent to daylight at the flick of a switch.
    Trying to propose fluro or even incandescent is superior to LED output and that LED is somehow a bad light source is just unfounded and incorrect opinion but if you want to argue Different, Provide some evidence otherwise.

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