DiY LEDs - How to Power Them

epicfail

Well-Known Member
Thank you, 100k ohm pot + 10k ohm resistor 1/4w+ will be fine.

I have 2 of these pots, it says 100k ohm on the webpage but one only reads up to 82.6k ohms with my multimeter, is that no bueno? The other one measures 91.1k ohms max.

https://www.futurlec.com/Potentiometers/POT100KBSWITCHpr.shtml

The part number on it is B104.

Im going to try the 91.1k with a 10k resistor.
I put a 9.1K resistor on because its what I had and it works just fine, I have the resistor connected directly from the blue and white wires right at the driver. I haven't tested a 5K resistor yet but when I get the arduino fading on/off working; I will want it to start at the lowest setting possible without the COB cutting out. I only recently realised how bad some pots were and started measuring them all. The closer the 100K the better, 82.6k is going to very limiting not being able to go any brighter than 82%.

When buying parts like that, just get yourself a few extra. They are so cheap to begin with and there is nothing wrong with having spare parts in case you let the smoke out. Also when I get resistors I usually get 1% instead of 5% tolerance ones, the price difference is negligible. My local electronics store sells them all in 10 packs so I usually get a few packs of different ones every time I go.
 

Bueno Time

Well-Known Member
I put a 9.1K resistor on because its what I had and it works just fine, I have the resistor connected directly from the blue and white wires right at the driver. I haven't tested a 5K resistor yet but when I get the arduino fading on/off working; I will want it to start at the lowest setting possible without the COB cutting out. I only recently realised how bad some pots were and started measuring them all. The closer the 100K the better, 82.6k is going to very limiting not being able to go any brighter than 82%.

When buying parts like that, just get yourself a few extra. They are so cheap to begin with and there is nothing wrong with having spare parts in case you let the smoke out. Also when I get resistors I usually get 1% instead of 5% tolerance ones, the price difference is negligible. My local electronics store sells them all in 10 packs so I usually get a few packs of different ones every time I go.
I got it hooked up with just the 91.1k pot right now, had to order 10k ohm resistors should be here in a couple days but works fine now with the pot only can dim up to ~90% of max current. Once I add a 10k resistor, I can dim down to around 10% and up to 100% current.

Couldnt I also have just added a 20k ohm or 2 10kohm resistors with the 82.6k (actual) pot and then be able to run at 100% current but only dim to around 20%?

Ive got the veg light built and running in the veg cab, only got the driver at ~1/2 current right now, 34w on the Kill-A-Watt.

BTW anyone wondering the HLG-60H-42B driver I got runs all 14 of the XML2s I had intended for the project, didnt have to take any LEDs out of the string due to maxing out vF of driver.
 
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epicfail

Well-Known Member
...I have the resistor connected directly from the blue and white wires right at the driver....
Ummmm, No I don't. That would be parallel, not sure why I wrote that.

I have it hooked in series, But only on the HLN-60H-42B with one CXA3070. Without the resistor the light cuts out before you dim all the way down, which I hear is not good for the driver. With the HLG-185H-C1050B and 4 3070's I have no resistor and don't think it is needed because when I turn the pot all the way down they still glow. Meaning even on the lowest setting the driver puts out enough voltage/current to meet the minimum requirements of four 3070's.
 
I
this will work...and get the right resistor... the loss here is about 1 Watt...example in the pic
Guod i have a question about the pic. Please bear with me im not new to electricity just LEDs. I would like to understand more of the circuit you have should me. The resistor are after the COBs on the ground side and that is to stop the vf from running by 2w or am i looking at it and thinking about it backwards?

How did you determine the the LOSS?

And if any of this is already posted by you or any body else I would love to read about it, if you know the name of the thread please let me know.

Again thank you Guod for taking the questions and to all others for your help and knowledge!!
 

Sevren

Well-Known Member
Thanks to all the helpful posts, I've got my quad CXA-3070 AB's up and running, but then my fan adapter blew during a stress test (aka leaving it on for 30 seconds). I'm not sure if it was my fault (wrong connections) or just a crappy adapter. I was using a simple 12V DC 1A adapter to power 4 arctic alpine 11plus fans (rated at .19A?). Any suggestions on another adapter? And if I were to get another similar one, which side of the plug is hot, as one side is not wider than the other?

 

AquariusPanta

Well-Known Member
OK I'm a little fuzzy with what you're doing. I sense your a little confused here but maybe I'm just really high.
lmao

Thank you Franja for clarifying that a simple chip on board and driver setup does not require the builder to include a resistor. I came here to better understand the more technical side, like what to wire the AC wires coming from the driver to and how to plug it all into the wall outlet but instead got all deluded under this hype about resistors.
 

epicfail

Well-Known Member
...I came here to better understand the more technical side, like what to wire the AC wires coming from the driver to and how to plug it all into the wall outlet...
Easiest way: stick the bare wires in the plug socket in the wall. Its good for testing but not recommended for permanent installations.

Cut the plug off some old unused garbage electronic device or extension cord and connect the wires . You can get cheap extension cord at "dollars stores".


7_outlet_wiring.jpg Cable_color_coding11.gif
Sorry I don't have a European plug pic and don't know if you're in North America. Hope this helps.

 

AquariusPanta

Well-Known Member
Cut the plug off some old unused garbage electronic device or extension cord and connect the wires . You can get cheap extension cord at "dollars stores".

My logic led me to this proposal after posting it. I actually have a surge protector opened up; plan on using it as the wire hub for my gizmos.

I can't wait til' I can start soldering wires together. It's been a few years since since I soldered the speakers to my amp and head-unit for my vehicle :peace: :hump:
 

SupraSPL

Well-Known Member
Thanks to all the helpful posts, I've got my quad CXA-3070 AB's up and running, but then my fan adapter blew during a stress test (aka leaving it on for 30 seconds). I'm not sure if it was my fault (wrong connections) or just a crappy adapter. I was using a simple 12V DC 1A adapter to power 4 arctic alpine 11plus fans (rated at .19A?). Any suggestions on another adapter? And if I were to get another similar one, which side of the plug is hot, as one side is not wider than the other?

Nice setup! Ya that adapter should have been perfect for the job may have been a dud. Hot and neutral are interchangeable in this case. Just to be thorough, you had the fans wired in parallel? All positives tied together and all negatives tied together.

Here is a cheap, OEM quality adapter that will be more efficient and reliable. You can tell if it is high quality if it says efficiency level iV or V or it may just have a V in a circle.
http://www.ebay.com/itm/DSA-12PFA-09-FUS-DVE-12V-1A-Switching-Power-Adapter-for-Dell-AS501-AX510-Speaker-/191353655766?pt=LH_DefaultDomain_0&hash=item2c8d9111d6
 

Sevren

Well-Known Member
Nice setup! Ya that adapter should have been perfect for the job may have been a dud. Hot and neutral are interchangeable in this case. Just to be thorough, you had the fans wired in parallel? All positives tied together and all negatives tied together.

Here is a cheap, OEM quality adapter that will be more efficient and reliable. You can tell if it is high quality if it says efficiency level iV or V or it may just have a V in a circle.
http://www.ebay.com/itm/DSA-12PFA-09-FUS-DVE-12V-1A-Switching-Power-Adapter-for-Dell-AS501-AX510-Speaker-/191353655766?pt=LH_DefaultDomain_0&hash=item2c8d9111d6
Thanks! Yeah I think it was a dud, the nerds at the electronic store were slightly unsure as well. I believe all the fans were parallel, I had to remove pins from the molex connectors to make sure all the black and red/yellows were aligned. But, still blew after about 30 seconds. I picked up one of these guys http://www.frys.com/product/7613847 , tested it before incorporating it into the build and so far working like a charm.
 

Sevren

Well-Known Member
Seems I've running into another problem. A big one. I've been turning CXA 3070 box on and after about 10 seconds of constant light, all 4 of the COB's themselves start to emit white smoke from the edges. Is this due to poor thermal grease or is something else at play here?
 

Bueno Time

Well-Known Member
Seems I've running into another problem. A big one. I've been turning CXA 3070 box on and after about 10 seconds of constant light, all 4 of the COB's themselves start to emit white smoke from the edges. Is this due to poor thermal grease or is something else at play here?
That sounds bad and not normal.
 
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