Stone_Free's Samsung Strip Build & Grow

Stone_Free

Well-Known Member
That value tell you the resistance of your pot, not the percent dimming. What is the value stamped on the pot?
Yeah I realise that dude. It's a 100k pot and the resistance I was getting, if I measured it correctly, was 1075 which I think is 107,500 which is 7,500 over the 100k, or 7.5%, meaning it dims from 0 to 107.5%. Rb was saying that often they are not exactly 100k. If the pot only has 94k resistance then it is 94% dimming rather than 100% at 100k......if that makes sense...if I got my measuring correct......a lot of "ifs" lol
 

Stone_Free

Well-Known Member
Got the basic frame built today. It needs some more cross members & slats adding which I'll do tomorrow. Luckily there is a timber yard 10 minutes walk from home where I can get all I need. Then I'll fit the blackout material, mylar, fans & lights so should be ready in a few days. Waiting on wire to arrive to connect strips together. Getting there slowly but surely! I'll put some pics up over the weekend.
Damn it was hard holding 3 pieces of wood in place whilst fitting brackets and screws...might have used an expletive or 37 lol :D
 

Sour Wreck

Well-Known Member
And pics you shall have. Tomorrow or Sunday. Deffo! :D
It's just a simple frame atm so nothing to really look at. I'll take a pic of it tomorrow tho', just so you can see the build from start to finish...and then more pics as I go along :)
How's your lights doing man?

check my thread in a few mins, will have an emulation photo up.

and, i am installing these in my tent tonight.

so we will get to see them in action later this evening. :bigjoint::blsmoke:bongsmilie:hump:
 

Rider509

Well-Known Member
Yeah I realise that dude. It's a 100k pot and the resistance I was getting, if I measured it correctly, was 1075 which I think is 107,500 which is 7,500 over the 100k, or 7.5%, meaning it dims from 0 to 107.5%. Rb was saying that often they are not exactly 100k. If the pot only has 94k resistance then it is 94% dimming rather than 100% at 100k......if that makes sense...if I got my measuring correct......a lot of "ifs" lol
LOL, no offense meant! I presume nothing when it comes to someone else's understanding of electricity. :)
I understand what you're saying but you have it kinda backwards. Consider that with no potentiometer connected you have essentially infinite resistance, and the driver outputs 100% power. The design requires 100K resistance to achieve full output. At 0ohms, or essentially a dead short, the driver will deliver the minimum design output. So if your pot was only capable of hitting 94K you wouldn't be getting full output. That's why it's important to measure pots if you want to be able to run wide open. At 100K and above the driver will deliver full output. Dimming occurs as you reduce the resistance across the dimming leads.
 

Randomblame

Well-Known Member
None taken man (: I appreciate your help and explanation.

Yeah I see what you mean now!
So just to clarify, the measurement I got of 1075 means it's all OK and I won't be under-running the driver?

Yepp!
It's most probably a 107,5k poti so you can use the full potential of the driver. As I said earlier, more does nothing but too less would limit the driver output.
You could also wire an on/off switch into the dimming circuit to switch dimming completely off.
If you look at the datasheet, dimming section(screenie below), you see the driver output can be up to 108% with open dimming circuit.
For a HLG-240 this means you could get another 15-20w by simply switch off the dimming circuit.
This means that the driver can deliver more than 100%, but not with the dimming function switched on. It has to be open to use its full potential. Most of the "B-type" Meanwells I have tested maxed out at 105-106% with open dimming circuit!
Screenshot_20171118-100639.png

On the picture of my old lamps you can see three switches next to the dimmers. The first one switches off the fans, the second one is the dimmer circuit and the third is to switch the Osram Oslon on/off.
 
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Randomblame

Well-Known Member
Of course, it can be doneScreenshot_20171118-110600.png later, no problem. Simple cut one of the wires and solder the switch in between.
Since there are only 10v in the dimming circuit you can use the cheapest mini switch you can find.
Like this below, 10pcs. 1£, e3ay!
 

dannykay

Well-Known Member
Perfect, thank you!
Is fitting an on/off switch something I need to do when I solder on the pot or can that be done at a later time?
I remember reading somewhere that it's not recommend to drive COBs less than 10% capacity (or using the dimmer function to on/off), I've put a 10k resistor on the pot that connects to the COBs driver. Not sure if it's the same with the strips, but I've used the same on my quantom boards just to be on the safe side.
 

Stone_Free

Well-Known Member
I remember reading somewhere that it's not recommend to drive COBs less than 10% capacity (or using the dimmer function to on/off), I've put a 10k resistor on the pot that connects to the COBs driver. Not sure if it's the same with the strips, but I've used the same on my quantom boards just to be on the safe side.
Thanks for that dude, I'll ask around. I don't think it is a problem....... maybe @Randomblame and/or @Rider509 can confirm?
 
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dannykay

Well-Known Member
Check this post/thread, that one of the places I remember seeing the 10k resistor reference

Meanwell doesn't recommend dimming below 10% if I'm not mistaken. It causes flickering type issues. The light will shut on/off with a light timer, unless you're going to physically turn it on and off every day.

Your potentiometer will look like this. You connect the positive +wire from the driver dimming to the + on the pot. Then you connect the -wire from the driver dimming to one end of the resistor and connect the other end of the resistor to the - on the pot. Done. Put some type of sheath or shrinkwrap over it and you're good to go. Buy any typical 50k ohm pot like THIS, some have nicer knobs than the other. Add any approximately 5k resistor like THIS.

View attachment 3896361
 

Stone_Free

Well-Known Member
@dannykay is right. Mean Well doesn't recommend turning the lights off with the dimmer, and the flicker that can be produced when dimmed that low isn't good for the lights.
Thanks for that @Rider509 and @dannykay much appreciated. I'll be sure not to dim them that low. I'll grab a resistor off of eBay in the next couple of days and fit it, just to be on the safe side. Really don't wanna damage my strips.....
 

Rider509

Well-Known Member
You must have sheep for neighbors. A lumber yard down the street but no place to buy electronics stuff! I'd go crazy. But then I'm a bit like the Monty Python couple scrounging in the dirt. "Oh look! There's a nice bit of filth over here!" Except my filth is the electronic innards of whatever has died.

edit: Speaking of sheep, when I was a kid we lost sheep to the coyotes. They'd get in under the electric fence in one spot. Enter one big bank of capacitors and a bit of wire. Who knew that you could explode a coyote? :shock:
 
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Stone_Free

Well-Known Member
You must have sheep for neighbors. A lumber yard down the street but no place to buy electronics stuff! I'd go crazy. But then I'm a bit like the Monty Python couple scrounging in the dirt. "Oh look! There's a nice bit of filth over here!" Except my filth is the electronic innards of whatever has died.

edit: Speaking of sheep, when I was a kid we lost sheep to the coyotes. They'd get in under the electric fence in one spot. Enter one big bank of capacitors and a bit of wire. Who knew that you could explode a coyote? :shock:
Haha! Yeah it's a bit weird not having a decent electricals store nearby. There is a store in town that sells basic stuff like plugs, mains cable, fuses but not one that sells resistors, single core cable, wire strippers or the stuff I need for this project. So glad that eBay is quick on delivering these days.
Gotta love Monty Python. I grew up listening to this record. It came out in '73 I think. This is part 1 of 4.


Exploding coyote LOL! That was the cousin of Wile E Coyote....Wire D Coyote :bigjoint:
 
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