New style Samsung LM561C Board

[PhenoMenal]

yep the 2 x QB-304 boards are run with parallel wiring off the one driver, so I just want to keep it simple and have one dimmer to equally dim both boards at once ... so a 50k is the way to go for that then? Thanks!
ps i like your idea of getting 10 and multimeter testing them, they're only like $1.50ea anyway, i dont mind spending an extra ten bucks to get an extra 10%

 

[PhenoMenal]

ah ok cheers no worries i'll wait til at least tomorrow before ordering them anyway to hear any more feedback

ps. what do you call five potentiometers hopefully trying to work together? a potential pentapotentiometer! *cringe*
... and it's only Monday folks ... (where's the Unlike button anyway)

 

[VJB]

Do we have a list of good board vendors on Alibaba?

Also, which vendor did OP get 'em from? Can't seem to find that here. Cheers!

 

[Theirongrow]

Do we have a list of good board vendors on Alibaba?

Also, which vendor did OP get 'em from? Can't seem to find that here. Cheers!

A list of good boards vendors? All the boards from alibaba are FAKE and all the boards vendors scammers.

 

[VJB]

So far 54 boards from Meijiu have been legit.

Incorrect.

Very interesting! Would you say they're the top source direct from China right now?

By legit do you mean confirmed top bin LM561C diodes used? Or diodes that are good enough to deliver good ass light?

Just very curious. Big thanks!!

 

[PhenoMenal]

oh no! it seems literally every Bourns 100k pentontiometer (PDB181-E218K-104B1) on the planet has been sold! I could not find a single source anywhere who had any in stock.
Does anybody know any suitable alternatives?
P160KNP-0EC15B100K by Welwyn Components / TT Electronics perhaps? it seems similar but i'm not 100% sure

 

[ANC]

You don't need a Bourns pot, man. Just get any pot that is 100k and remember a 10K series resistor so there is always 10k minimum resistance even if you turn the pot to 0. Quarter Watt is probably enough.

 

[PhenoMenal]

ok thankyou, i will try the P160KNP-0QD20B100K !

 

[burnpile]

I just bought some on amazon, came with the knob, worked good, i also got the resistors and put one in but really don't know why.

 

[PhenoMenal]

which resistor?

 

[ANC]

10K 1/4W should be enough, that wire only carries microamps of current.

 

[Randomblame]

@PhenoMenal
There is no need for an additional resistor. Simple solder the dimming wires to the left and the middle prong of the poti. Minimum output of a MW driver is 6-10%, with an additional resistor you can set the limit higher. 10k resistor means min. 10% output, a 25k resistor means 25% minimum.
I do it without, because I can better inspect the plants, if I can regulate the light down to 6%.

And here are 10x B100k linear
https://www.ebay.com/itm/10-pcs-100K-ohm-Linear-Taper-Rotary-Potentiometer-Panel-pot-B100K-15mm-NEW/381407284114?

https://www.ebay.com/itm/10-x-B100K-100K-Ohm-Linear-Taper-MINI-Potentiometer-Pot/262518005371?hash=item3d1f4ade7b:g:e6gAAMXQjWtRKihi

 

[PhenoMenal]

where in the circuit does the resistor go!? I've only used resistors to drop the load never increase it, so i'm confused how to use a resistor with a potentiometer to keep it at 10kΩ/above zero ?
Nice find with the B100K's btw, thanks! I guess using the model number isn't the best way to go

 

[Randomblame]

Add the resistor between the white wire and the left resistor prong when you want a 10% limit, but it's simply not needed. You can stop manually at 10% or where ever you want.

 

[PhenoMenal]

thankyou!!! just to be clear though, when you say 10% limit, you mean it will always keep the LEDs running at 10%, ie. never 0%? eg, 'level 10' on the knob would still permit ~100%, while level 0 would go no lower than 10%?
(I don't want to risk accidentally manually turning it down to 0 if it will damage the LEDs ... but [is that the case]!?)
I'll also do some breadboard experiments first

 

[Randomblame]

thankyou!!! just to be clear though, when you say 10% limit, you mean it will always keep the LEDs running at 10%, ie. never 0%? eg, 'level 10' on the knob would still permit ~100%, while level 0 would go no lower than 10%?
(I don't want to risk accidentally manually turning it down to 0 if it will damage the LEDs ... but [is that the case]!?)
I'll also do some breadboard experiments first

Meanwell HLG series drivers are dimmable (without resistor) between 6 and 100% (with 110k potentiometer a tad more[108%]).
If you use a 10k resistor, it is between 10 and 100% dimmable.
If you take an ELG series driver you can dim to 0. And no, that does not damage the LEDs. In fact, dimming even extends the lifespan.(lower Tj.)

 

[Joe Dirt 23]

I'm not a member here but I have been kind of following this thread. I thought I would share my experience. I ordered 6 288 boards in 3000k with lmc561c s6 diodes off Alibaba. They arrived yesterday and I installed them on a 38"×38", 3/16 thick, 6061 aluminum. I'm running the 6 boards off 3 ELG-240H-C2100 drivers. When running I can rest my hand anywhere on the back of the light and leave it there. My tent dropped 6° immediately from 26° to 20°. The light seems much brighter them by 1000w HPS and MH. I put my Klein clamp on amp meter and got 6.5 amps off the 6 boards. So 120v × 6.5a=780 watts at the wall. 2 HLG boards are rated at 260 watts so mine seem to be spec. Any non confrontational opinions are welcome. I don't have an image sharing host so out of luck there. Here's a video but it doesn't do the light justice because it dims so you can view the light.

 

[VJB]

I'm not a member here but I have been kind of following this thread. I thought I would share my experience. I ordered 6 288 boards in 3000k with lmc561c s6 diodes off Alibaba. They arrived yesterday and I installed them on a 38"×38", 3/16 thick, 6061 aluminum. I'm running the 6 boards off 3 ELG-240H-C2100 drivers. When running I can rest my hand anywhere on the back of the light and leave it there. My tent dropped 6° immediately from 26° to 20°. The light seems much brighter them by 1000w HPS and MH. I put my Klein clamp on amp meter and got 6.5 amps off the 6 boards. So 120v × 6.5a=780 watts at the wall. 2 HLG boards are rated at 260 watts so mine seem to be spec. Any non confrontational opinions are welcome. I don't have an image sharing host so out of luck there. Here's a video but it doesn't do the light justice because it dims so you can view the light.

Wow! Which vendor did you get them from? How was your ordering experience like? Thanks!

 

[Viceman666]

Hello I have a question. So Im getting 2x two qb304 (from china shhhhhh ) with 2x driver HLG-240H-c2100b
So one driver for 2 boards

I dont know much about electricity and I tried to read about it but it still looks like chinese to me

Correct me if Im wrong.. my understanding is volt x amp = watt

Options to plug the board is series or parallel lets assume I leave everything at 100% power

So if I do series it would mean volt add up and amp divide.. so for example a qb304 board is about 100-115 volt. If I put them in series the driver would need 200-230v and each board would have around 1050mA (the driver is 2100mA)---- that being said for that specific driver it appear max Volts is 119v (unless im looking this wrong) so only option would be to go parallel.

If I do parallel that would mean half the volt for 2 boards but double the mA so each bord would be around 50-57.5V per board at 2100mA but board capacity i think is around 1600mA

Im clearly not understanding all those electric thing so any help would be great!

Thank you

 

[Joe Dirt 23]

Wow! Which vendor did you get them from? How was your ordering experience like? Thanks!

I dealt with Russell at R2T. He was a pleasure to deal with. He is easy to communicate with. Responds quickly. He had 15 days to build the boards and mail them and I explained how my current light stopped working and if he could try to send them as soon as possible. He got them done in 10 days. I ordered 6 boards in 3000k and I will be ordering some in a few months 5000k or 4000k for veg. There was a vendor selling $10us less a board but he was jerking me around. I ordered 6 board through him and a week into the 15 days he tells me he can't get 3000, would I take 4000k. I said no and got a refund. I then went to Russell at R2T. If you go to Russel, tell him Joe Dirt sent you.