Let's talk DIY lights


@daddy yep that’s what a dehumidifier is for. Lol. That was a needed purchase. Temperatures are mild comapared to lower Michigan. I miss the snow.


Side note… I spent time in Adak when I was very young. Too young to remember, but I was there lol.


@1BigFella yes the entire rapid LED kit, frame and everything. Not just COB’s. If it were just those even $100 to AK is ridiculous. Lol


@dbrn32: I’ve been to Adak, too! Research ship back in the 70’s. I got to walk around on the Western tundra, which was actually a couple feet thick in mid-summer. Very strange. Lots of seals and sea otters.


Sounds like qb 304 and kits will be available at hlg in about 30 minutes.


Question for all you light gurus.

At some point this winter I am going to get a 2x4 tent to set up as a veg station. When I do that, I plan on moving one of my two cheapo LED panels into the 2x4, and replacing it.

I am considering buying an LED Kit like the 260w QB LED Kit at HLG. I figure buying a kit and putting it together would be a good primer on what all goes into building an LED, rather than trying to figure it all out from scratch.

Does this seem like good reasoning, or should I do more research and actually buy components separately?

A couple of those 260w QB LED kits looks like it should flower my 4x4 tent well. Throw in one of my two 1500w cheapo panels and I might be cooking with gas…


The hlg kits are excellent introduction to diy lighting. They send everything you need, and you can even find some assembly videos on youtube. Pretty much risk and hassle free.

The only real downfall to the kits is that you pay about a $40-$60 premium for the buy it all in one shot at one place. For a lot of people though they find a lot more confidence in doing that. These kits are really more of assemble yourself than do it yourself, and there’s a lot to be said for that. Especially for your first project.

Hlg now offers a new heatsink that flips the orientation of the boards 90 degrees, you’ll want to make sure you get the older design if going that route. Probably what they refer to as 260 watt xl kits, 2 of those would have good board spacing in a 4x4 to light it up very well.

Also, I think we’re about to see some new boards from hlg. So if you’re not in a big hurry, maybe standby for a bit. I’m thinking there will be 90 cri options, possibly a more efficient Samsung chip, and maybe even a different string ratio to change up voltage and currents.


I did find a 7 part series on DIY lighting on YouTube that has been extremely informative. Especially the first one - “LED Basics,” where he describes what each part is, what it does, what forward voltage means, etc. For a newb to the world of electronics it was really helpful to just understand all the stuff you guys talk about with ease.


Growmau5? Probably one of if not the best resources on youtube. Led gardener is another good one.

You can never have too much information @Bogleg!


I was just outside fixing some avocado irrigation when I got attacked by killer bees! Only one sting so I must have been pretty far from the hive. You can run faster than honey bees can fly but that doesn’t help if you fall down. Just some lacerations and bruises, and meat tenderizer took care of the sting. I was actually very lucky.

Growing inside is SO much nicer! Now I have to go to Fry’s and get one last part for my DIY COB rig.


Ouch! Them cobs will do you some good.


@1BigFella wanna borrow my shotgun in case they come back? Lol


@1BigFella here’s a little diy project for them.



Fired up one of my total DIY COB fixtures last night: It’s only running at 789 ma instead of the target 1140 because my capacitor is too small, but holy crap it’s blinding! I ordered a cap that is 10 times bigger. That should help. The incoming voltage peak charges up the capacitor to 170 volts but then the COB and current limiter drain the charge down too quickly. The solution is a lot more capacitance but the voltages and current limiting are working.

My current limiter is one giant resistor: 33.3 ohms at 75 watts, which should limit it to about 1140 ma when the input voltage is 120 VAC. The circuit is pretty forgiving because even 132 volt input surges will only drive it to 1528 ma, which is well less than half of what the COB can handle. Since I am using two of the Vero 29 high voltage parts in series, my efficiency is about 80 %. Not as good as the Mean Well drivers but then again only about $10 for two COBs. Still should get about 160 lumens per watt.


@1BigFella. You should be able to measure voltage and current on both sides of your power supply to calculate efficiency right? Is that how you’re coming up with the 80%?


Congrats on the build too!


When I get it to the finished state, I’ll measure the efficiency. It’s a little difficult to actually measure now because my meter averages the 120 Hz pulsing readings. It has to charge to 170 VDC because there’s little resistance in the inflow path but a 0.7 ohm NTC and the ESR of the capacitor. (And I measured that before connecting the COBs.) But then when the line voltage goes lower, the LED drains a lot of charge out of the capacitor. I can measure the average current in the LED side and it’s about 789 ma. It should be about 1140 ma at the peak so that shows you how much it is drooping. A bigger cap should fix the drooping.

I can calculate the efficiency by taking the voltage across the LED COBs and dividing that by 170. That is 79.2% The other 20.8% will be across the big resistor and will be converted directly into heat. Of course the COBs also have their own efficiencies but that is taken into account by the 200 lumens/watt figure.

My watt meter says 143 watts right now on the line side, but what the COB does is very complicated because it is not a straight resistive load. It puts out about 200 l/w when it is drawing 1140 ma but even more at lower voltages and currents.


New to sight, first grow, diy lights.90, 9w/60w led equivalent in parallel

Wired in parallel topped off all contacts with liquid electric tape.

Originally was supposed to get 7 in one fixture through ebay From Hong Kong never came already had bulbs so I had to take matters in my own hands a lot of frikin work. Hoping to pull at least .5 per watt. Thoughts


Those are essentially a19’s with diffusers removed? Hard to tell from pics, but looks cool!


If you don’t mind me asking, where does the 170 come from?

I typically just measure power in vs power out. Haven’t had an issue ever doing it on any of my builds. If I’m pushing the heatsinks you may see a little voltage droop there over time, but that’s about it.

You definitely get a little boost in efficacy at lower current. But you’re also running less overall output while still consuming that power from wall. Not exactly sure if I would consider that a trade off. If you were dimming to 700ma range and then also seen a relative drop from wall draw, then you could consider that running more efficiently.