The Planted Tank Forum banner

Here’s a fun one - Can I convert a black box to RGB

380 6
Premise: I have a 2 of the black boxes that have grown plants very well, not the best color rendering but definitely lush growth. These have now been retired and I’m wondering if there’s maybe a way to convert the blue channel over to RGB. My understanding is that RGB led diodes operate at a higher wattage so at 1 to 1 conversion would not be possible. What would be the next best option in order to achieve this.

thanks
1 - 7 of 7 Posts

· Premium Member
Joined
·
238 Posts
You’re in luck, that’s exactly what I did. Color turned out great. This thread probably covers everything you need thanks to big help from @jeffkrol

 

· Registered
Joined
·
124 Posts
Discussion Starter · #3 ·
Thank you, I quietly followed your thread with great interest. I’m considering this route if what I’m thinking is not possible.
Basically I would like to avoid the individual colored LEDs and want to use one of the all in one RGB ones. This would avoid the need to try and balance the individual diodes. If adding RGB LEDs is possible I would be able to control them instead.


You’re in luck, that’s exactly what I did. Color turned out great. This thread probably covers everything you need thanks to big help from @jeffkrol

 

· Registered
Joined
·
13,292 Posts
Thank you, I quietly followed your thread with great interest. I’m considering this route if what I’m thinking is not possible.
Basically I would like to avoid the individual colored LEDs and want to use one of the all in one RGB ones. This would avoid the need to try and balance the individual diodes. If adding RGB LEDs is possible I would be able to control them instead.
Well "technically" you could do that BUT it is a bit more work and you need to like the RGB native balance.
Most will be like 10000k look with all colors driven equally.
Technically there are 2 ways

Now for the complication with ONE way
A three up rgb diode with all in series will have a V(f) of around 9V or so..
So you need to decrease the amount of diodes running on the driver.
Take the channel with 28 leds.
Roughly the V(f) will total 92V-ish
Sooo you only use 10 of the RGB (in series) diodes.
You will need to solder a jumper over each "missing" diode.
Make sure any voltage is below the drivers max DC out.
Wiring all three in series is a bit tricky.
You would need to carefully bend the ears up which can crack the plastic/ceramic case but has been done successfully.
Point is it can't touch the contact points on the circuit board except for the 2 marked +, -.
Not an insurmountable problem.
Kitchen utensil Gesture Tableware Art Drawing


This will run each at the "normal" 550mA current but adds up to 3 diode replacement each.
The overall chip needs to be rated "9W".
Actually about 5.6 Watts..


Now the EASY way.
Just solder the chips so all 3 colors are in parallel.
This will divide the 550mA current between the 3, probably a bit unevenly but that is another issue.

Automotive lighting Amber Jewellery Natural material Glass


Voltage across should be "normal", around 3.3v
Chips only need "3W" rating.
.183 x 3.4 + .183 X 3.4 + .183 x 2.4 = .622 + .622 + .44 = 1.68 Watts​
 

· Registered
Joined
·
124 Posts
Discussion Starter · #5 ·
Thank you for the detailed response. It’s much appreciated. Now the ultimate question would be is there a benefit to doing it like this vs how @Eric Tran
Did it.

@Eric Tran would you mind sharing your final lay out?
Also, where did you get your led chips from and what color temps did you end up ordering.

thank you in advance


Well "technically" you could do that BUT it is a bit more work and you need to like the RGB native balance.
Most will be like 10000k look with all colors driven equally.
Technically there are 2 ways

Now for the complication with ONE way
A three up rgb diode with all in series will have a V(f) of around 9V or so..
So you need to decrease the amount of diodes running on the driver.
Take the channel with 28 leds.
Roughly the V(f) will total 92V-ish
Sooo you only use 10 of the RGB (in series) diodes.
You will need to solder a jumper over each "missing" diode.
Make sure any voltage is below the drivers max DC out.
Wiring all three in series is a bit tricky.
You would need to carefully bend the ears up which can crack the plastic/ceramic case but has been done successfully.
Point is it can't touch the contact points on the circuit board except for the 2 marked +, -.
Not an insurmountable problem.
View attachment 1048798

This will run each at the "normal" 550mA current but adds up to 3 diode replacement each.
The overall chip needs to be rated "9W".
Actually about 5.6 Watts..


Now the EASY way.
Just solder the chips so all 3 colors are in parallel.
This will divide the 550mA current between the 3, probably a bit unevenly but that is another issue.

View attachment 1048797

Voltage across should be "normal", around 3.3v
Chips only need "3W" rating.
.183 x 3.4 + .183 X 3.4 + .183 x 2.4 = .622 + .622 + .44 = 1.68 Watts​
 

· Premium Member
Joined
·
238 Posts
Well "technically" you could do that BUT it is a bit more work and you need to like the RGB native balance.
Most will be like 10000k look with all colors driven equally.
Technically there are 2 ways

Now for the complication with ONE way
A three up rgb diode with all in series will have a V(f) of around 9V or so..
So you need to decrease the amount of diodes running on the driver.
Take the channel with 28 leds.
Roughly the V(f) will total 92V-ish
Sooo you only use 10 of the RGB (in series) diodes.
You will need to solder a jumper over each "missing" diode.
Make sure any voltage is below the drivers max DC out.
Wiring all three in series is a bit tricky.
You would need to carefully bend the ears up which can crack the plastic/ceramic case but has been done successfully.
Point is it can't touch the contact points on the circuit board except for the 2 marked +, -.
Not an insurmountable problem.
View attachment 1048798

This will run each at the "normal" 550mA current but adds up to 3 diode replacement each.
The overall chip needs to be rated "9W".
Actually about 5.6 Watts..


Now the EASY way.
Just solder the chips so all 3 colors are in parallel.
This will divide the 550mA current between the 3, probably a bit unevenly but that is another issue.

View attachment 1048797

Voltage across should be "normal", around 3.3v
Chips only need "3W" rating.
.183 x 3.4 + .183 X 3.4 + .183 x 2.4 = .622 + .622 + .44 = 1.68 Watts​
Didn’t know about this “easy” way. How would you dim each rgb though and would all diodes be able to be used?

Thank you for the detailed response. It’s much appreciated. Now the ultimate question would be is there a benefit to doing it like this vs how @Eric Tran
Did it.

@Eric Tran would you mind sharing your final lay out?
Also, where did you get your led chips from and what color temps did you end up ordering.

thank you in advance
Final layout would be near the end of the thread. Curious what brand black box do you have? I found the leds on aliexpress for cheap and they’re still working just fine for me.
 

· Registered
Joined
·
13,292 Posts
Thank you for the detailed response. It’s much appreciated. Now the ultimate question would be is there a benefit to doing it like this vs how you did it
Just another way to skin a catfish.
Well might be a blending improvement.

Didn’t know about this “easy” way. How would you dim each rgb though and would all diodes be able to be used?
You wouldn't be able to separately dim the ind colors.

Yes you can use all the diodes. It will just be a 3 core diode or " cob" like if you run all 3 in parallel.

Just like this sort of.
Font Number Document Parallel Screenshot


Just another type of " white" really

NOTE:
I'm not Exactly sure this all works.
Also I made a mistake in the calc above.I used system current not current at the diodes (550/3).
 
1 - 7 of 7 Posts
Top