DIY led grow

Positivity

Positivity

Well-Known Member
Seems to have run into a problem..

Hooked my light to a kil a watt to see the draw. Only 95w..I thought they were kinda dim..

So the driver came with only two wires on the dimming circuit. I thought there would be a 10v source like the others I have. Nope!

So I read through the data sheet and saw a resistor type setup. Setup my pot with the ground wire on the wiper and the other voltage line on one of the ends..to make a voltage resistor. I think at least..trying to figure it out..

But not getting full output?

So me thinks I need a seperate 10v source...darn it. Was trying to avoid that

Any ideas/suggestions to get this dimming set up?
 
Positivity

Positivity

Well-Known Member
Thanks supra. That's what I've been doing all this time. This driver is different, only two wires. Looks like they left the 10v source out like the meanwells.

Just need to get a 10v power supply I think..set it up like a meanwell.

Now I need to find a really small 10v supply to fit in my project box

This was pretty bright at 95w..lol. 200w more! I gotta see this..
 
stardustsailor

stardustsailor

Well-Known Member
Hey Posi ...

-If it is "resistor" dimmed ,you do not need a 10 V power supply ...
You need a pot with R / N value ( R=resistance value of max-100%- output power / Number of drivers to be dimmed simultaneously ..

-A link of the driver's datasheet,would be useful ,here ...



- Even if it takes 10 V power supply for the drivers to be dimmed,

a) Just use a simple LM 317 ( $.5 ) adjustable voltage regulator with a pot ..
After the 12 VDC output of the Fan's PSU
(You 'll have to choose res values ,in order to 'program ' it to output 1.25 - 10 VDC ...)
programming lm317.JPG

(Forget the Iadj*R2 term ...Don't calculate it ...)
http://www.ti.com.cn/cn/lit/ds/symlink/lm117.pdf
http://www.fairchildsemi.com/ds/LM/LM317.pdf

b ) Or you can use ,in series ,one after another (starting with largest )
,
few constant voltage regulators ,output selected by a rotary switch ....

Like LM78012 => ML78010=>LM7809=>LM7806=>LM7805=>LD33

(LD 33 pin out differs from rest .Middle pin/ case is output ,instead of 'Ground" like on LM's ...)

http://read.pudn.com/downloads139/doc/project/597623/三端器件/LM7805_1233165.pdf

http://www.digchip.com/datasheets/parts/datasheet/064/LM780X.php

http://www.fairchildsemi.com/ds/LM/LM7805.pdf

You'll need some few additional passive components ,mainly capacitors ...

Very cheap,easy ,efficient ...

Example of circuit "voltage regs in series ,out selected via rotary switch " :
(This is a whole power supply ..
Just check the 78xx's and the rotary switch output selection ...)
stablised-power-supply-with-short-circuit-indication_med.jpg
 
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stardustsailor

stardustsailor

Well-Known Member
Positivity said:
Heres a link to the datasheet..http://www.inventronics-co.com/upload/EUC-200SxxxDT(ST)_2013112801453103111.PDF

Looks like two ways, resistor or dc input.

Dc input looks to have a more gradual curve. Resistor jumps up rather quickly.

Only problem is there diagram is really vague. I assume 10v source needed and I could use the pot I have?
Click to expand...
dim method.JPG




Dimming method #1 :
Via Voltage n'Signal " 1-10 VDC, 200microAmperes max current needed..

Solution A : IC LM317 (1.25-10 VDC ) after 12 CV PSU ..

R1 : 560 Ohm R2 (pot ) : 5K . (pot connection : Pin 1 -'start' - to R1. Pins 2 -wiper- & 3 -end- ,together commonly connected to Ground. )


Vmax =10 V (9.9 to be exact ...) = 1.25 ( 1 - 5000/560 ) ..
You can change the values to a better 'fit' ....
It is just a ..quick calc example ...


Solution B : In series voltage regulators of the 78xx 'line' .
Last ones ,can be two LD 33 ,one at 3.3 V and the other at 1.2 V

http://doc.chipfind.ru/nsc/lm1117ld33.htm


Dimming method #2 :
Via pot >200K pot needed for one driver .

For dimming both drivers simultanouesly ,
parallel connect commonly their purple and grey wires ..
(purple wire from driver #1 with purple wire from driver #2 ..
And grey from driver #1 with grey from driver #2 ...)

Then connect purple pair to the 1 or 3 pin of the pot (start or end ,it does not matter ...
It matters only in the 'motion' of the pot ..Clockwise or counter clockwise the dimming should be done ...)

Connect the grey wire pairs to pot pin 2 (wiper ) ....

Pot value for two drivers dimming ) has to be of 200 K / 2 = 100 K .

(if it works same as on MeanWells ..Which probably is the case ...)
 
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stardustsailor

stardustsailor

Well-Known Member
Posi,the way I see things ..
The most easy and space,time,money saving dimming option is the 'Pot' option ...
It takes only a pot and nothing else ...

(200K for one driver => 2 x 200 K pots for separate driver dimming
or
100K for simultanouesly dimming both drivers ... )

Notice the datasheet's graph ....

From 0 to up 10 K ,power output is at 10% (minimum current = Iomax *10 / 100 )

And reaches at 100% ,just something less of 200K ..
(for one driver .... )

If you want you can add a resistor (or a trimming pot ) in series with the pot
to set minimum output current .

Example :

Wanted range 350 -2100 mA ...

350mA is 350/2100 *100 = 16.6% of Iomax (2100mA ) .....
From graph 16.6% is about ~12 K ...

12K / 2 drivers = 6 K

A series resistances of 5.6 K+ 360 (or 6x 1K ) with a 100K pot ,will be
dimming the drivers to the 350-2100mA range ...

(pot will never go to '0' .Min value will be 6K ... )
 
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Positivity

Positivity

Well-Known Member
So it Was right there in the graph. I was using a 10k pot..and it wasn't giving me the full range.

I think I'll leave the trimming pot out this go around. I don't really need to set a lower limit. Actually the lower the better..I've been dimming my lights all the way down when I work in the area.

Amazing your ability to work out the math with these items. I'm trying to make sense of these things but it's sometimes hard to find the resources to put the whole picture together.
 
stardustsailor

stardustsailor

Well-Known Member
Positivity said:
So it Was right there in the graph. I was using a 10k pot..and it wasn't giving me the full range.

I think I'll leave the trimming pot out this go around. I don't really need to set a lower limit. Actually the lower the better..I've been dimming my lights all the way down when I work in the area.

Amazing your ability to work out the math with these items. I'm trying to make sense of these things but it's sometimes hard to find the resources to put the whole picture together.
Click to expand...
Posi,from what I can see ,you 've already a certain 'level in electronics ..
Practice and experience ,always they teach more and more ...
It's not really some kind of special ability ...
I 've been 'there' before ,so I got to 'know' some things ...
In fact I have been same-if not more- dazzled and confused like you feel ...
But , I've asked,studied ,tried,failed ,practiced ,etc ...

But ,hey ..
Nothing's impossible ..


As for the lower limit ...
You can skip the trimming pot and have a simple 1/4 W resistor ..
A lower current limit,is something good to be there .
Driving leds too low (*below a limit ..) is not advisable ,by led / chip manufacturers..
Leds/ chips run 'unstable' and nasty things may/can occur ...
 
Positivity

Positivity

Well-Known Member
Little progress..tightening things up

Cut the pot off for now. Now full draw with everything is 380w.

Osram hyper reds mounted with coolpad thermal adhesive. They have a 30psi and 200psi strength "temporary" bond. I chose the 30psi for now. All stuck good except one..going to cycle the lights on a few times to see if the heat helps it bond completely. No screws...didn't want to commit to placement. If this dosent work I'll try the 200psi version.

Got a few weeks before I switch lights out so I'll take my time working out the kinks..

Heatsink warms up just a bit...less than my xml light with 20 more watts..just about right. Glad I didn't push them harder. Will try and take some Tj measurements later

All reflected

image.jpg image.jpg
 
Positivity

Positivity

Well-Known Member
spazatak said:
are you only using 2 drivers in that pic man...

I thought each COB needed an individual driver...
Click to expand...

No..there are other options available. Once you start going over one cob your in high voltage range though. I thinks it's 60v and up (don't quote me on that) is considered high voltage and more dangerous to work with. I did a bit of high voltage research while waiting for parts...I'd recommend anyone considering these type drivers to study first.

Inventronics brand goes up to 300w I think..

I'm using 2 200w 1.05a drivers. Each running 4 cxa 3070 with 30w extra room for whatever will run at 1a current. One driver is maxed out at 204w...not sure I'm going to leave it that full..may take an led or two out. It's running cool with minimal airflow..
 
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