Let's talk DIY lights

They are not dimmable because LEDs don’t work like incandescent bulbs. They have to have the minimum forward voltage to make any light or conduct any current. Then the current can go up maybe 4 times and the voltage will rise just a few volts. So you have to dim them by controlling current, not voltage. If you had the really cheapo “big resistor” driver than you could dim them just a bit, but with a better driver it will regulate at just the same current until the voltage drops too much and then they shut down completely.

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What is in these that’s not in a standard bulb?

https://www.amazon.com/gp/aw/d/B01MFGH6EQ/ref=mp_s_a_1_6/146-7095504-1056211?ie=UTF8&qid=1511469548&sr=8-6&pi=AC_SX236_SY340_QL65&keywords=dimmable+led+bulbs&dpPl=1&dpID=31UmLw%2BOB2L&ref=plSrch

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Assembly and wiring. Oh yay!

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Looking awesome @Daddy let’s see how bright it is!

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Still wiring …it’s tough, I’m half drunk stuffed full of food and watching a movie while trying to get it done lol @Covertgrower

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That’s commitment right there @Daddy don’t work too hard…

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half done.

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Looking great! Did you decide to go with constant current hlg 320?

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Yes constant current 320s. Everything just got ran up on individual drivers. The 4000k’s draw 332 watts at the wall. Deeper light penetration and heat. The 3000k’s draw 337 watts and actually seem to run really cool but have less strength. Cheapo light meter shows that the 4000s have the same output as the 3000s 9 inches farther away.

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there’s 1Kw of light gentlemen.

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More photons in the 4000k, better photons in 3000k. That’s about the only way to look at it.

When you calculate led Watts, what’s difference between that and wall watts? And do you have dimmers wired in?

The way they are sitting there, are they hooked up to light controller? Or just plugged into 120v?

I think you did a great job, congrats on the build?

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Just plugged into 120 outlets on individual cords for testing each separate string. I will wire them all into a junction tomorrow so only 1 power cord. So if the driver output is 320w max +/- 2% then my driver is using the other 15w correct? Pretty high efficiency. And yes each driver has its own pot.

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Possibly. Assuming you have the driver loaded to 100% and you’re not seeing any unintentional dimming from your pot having too low of resistance.

If I remember, fv at 2100ma is like 37.6 right? If so, 37.6x4=150.4. 150.4x2.1=315.84

Subtract led Watts from wall watts and you’ll have driver efficiency loss. On the 3000k, 337-316=21 Watts loss or 93.7 % efficient if my math is right. Obviously I rounded to 316, but it’s close.

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My math came out the same so a little bit better efficiency on the 4000k. 947 true watts for $840.

And I actually tested with and without dimmers wired in and had the same wattage draw so I know the dimmers are actually running at 100%

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As long as they are 100k or more I think is all that’s required. Although, it should’ve been a little higher with dimmer circuit open. Most of the hlg b series will put out a little more than rated current with it open

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Ya, there not really any issue with including driver loss in what you say they draw. Everyone else does. They draw what they draw, you just have the benefit of knowing that you have about as efficient as driver that’s available. Mainly because you bought a good one, but also because you filled it properly. Most can’t say that.

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Also I had alot of the things I needed that weren’t in the cost. But even someone that has to buy everything can still build a high quality light for less then $1 per watt.

And you are right about slightly higher with the dimmers open but it was .3 I believe. My pots are over 100k but not sure what their rating is (rapid led) I checked when I purchased and verified that my driver’s could be dimmed to zero.

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Ya, I have a dimmer from them as well. If I remember, mike told me they purposely weed through them and remove any less than 100k. Being over not really a big deal, will just have a touch of deadband in the knob. But they will dim linear. So if max was 97k then you’d only get 97% of the output current. It’s just good to verify.

I agree, you’re good dim to zero. Not that you’d really have any reason to do so. But if you fat finger it on accident won’t be an issue. I knew some of the newer drivers were, but not which models for sure. So I went and double checked.

Now that you’re flinging photons, what’s the first experiment?

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Right on, and enough said. I was just curious, so by all means fly under radar.

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That’s a pretty good driver! I assume it’s a full switching current regulator. They can get up around 95% if you do everything right and hold yer mouth just the right way. Once you get an inductor in there for supplying current when the power is switched off it gets kind of squirrelly. You get voltage ringing you need to snub, you have to protect your semiconductors from EMF spikes, and such. Lots of little improvements that make the output smoother but cost a little efficiency.

The ones that I have done used a little microprocessor to sense the output voltage and switch the MOSFETs on and off. Nice because you can program it to do whatever you want. For example, one was a boat generator voltage regulator that could charge 12 volt or 24 volt “house” batteries and a starter battery. Or it could use either one of those batteries to charge the other. It could even take a 12 volt input and charge a 24 volt battery. It was buck-boost so it could go either way. Impossible to find an off-the-shelf part that would do all of that.

That dimmable LED lamp is probably just a big resistor current regulator. That’s why it is so inefficient: Just 107 lumens per watt. That’s because so much of the power is being burned up by the resistor. The minimum voltage is probably about 70 volts VAC input, so it makes a little light. When you dim it less it burns up most of the voltage difference in the resistor but that sends more current through the LEDs.

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