After seeing how far LED lights came, I knew I would be building one. Special thanks for everyone who donated their time and information for this project. Countless hours researching and messaging people about their setups. I made this DIY to help some of you that are interested in LED lights and/or looking for information about assembling your own.
Replacing an old 250w HPS for a 4.5 Sq Ft Tent 1.5ft x 3ft (46cm x 91cm).
Samsung LED LM561c diode:
This hands down this is arguably the best diode out there right now at an affordable price. It has a range of options that can be used build your own custom light spectrum.
- CCT (K):2700K ~ 6500K
- CRI (Color Rendering Index):80
- Size / Dimension:0.197" L x 0.118" W (5.00mm x 3.00mm)
- Height - Seated (Max):0.032" (0.80mm)
- Mounting Type:Surface Mount
- Current - Max: 200mA
- Current - Test:65mA
- Lumens/Watt @ Current - Test:176 lm/W ~ 201 lm/W
- Package / Case:4-SMD, Flat Leads
- Packaging:Tape & Reel (TR)
- Supplier Device Package:5630
- Thermal Resistance of Package:12°C/W
- Viewing Angle:120°
- Voltage - Forward (Vf) (Typ):2.6V ~ 3V
Here are the LM561c CRI 80 (S6) diode spectrums
3500K and 4000K offers the best of both worlds for vegetative and flowering growth. The possibilities are endless.
QB288 vs SolStrip X1 vs H562D:
I was drawn to the Quantum 288 board, SolStrip, and H-Series Gen3 LT-H562D. All these board are in the same class because they all have the LM561c diode and only vary with the amount of diodes on board.
The Quantum QB288 Specs:
- Size: 286mm x 174mm (11.25” x 6.833”)
- Power: 151.2 watts, constant current, no resistors
- LEDs: 288 diodes Samsung LM561C top bin
- CRI: 80 (S6)
- LED Color Temperature: 3000°K, 3500°K, 4000°K, 5000°K
- Efficacy: 161 – 212 lm/w
- Power Consumption: 133.6 to 152.6 W
- Operating Current (If): 2800 mA
- Operating Voltage (Vf): 47.7 to 54.5 Vdc
- Max. Current Rating: 3000 mA
- Cost: $75/board
The SolStrip X1 Specs (My Revisions):
- Size: 400 mm x 30 mm (15.75” x 1.2”)
- Power: 50.4 watts, constant current, no resistors
- LEDs: 96 diodes Samsung LM561C top bin
- CRI: 80 (S6 bin), 90 (S3 bin)
- LED Color Temperature: 3000°K, 3500K, 4000°K, 5000°K (2700°K, and 5700°K tba)
- Efficacy: 161 – 212 lm/w
- Power Consumption: 38.6 to 50.8 W
- Operating Current (If): 2100 mA
- Operating Voltage (Vf): 20.8 to 24.2 Vdc
- Max. Current Rating: 2400 mA
- Cost: $20/board
The Samsung H-Series Gen3 LT-H562D Specs:
- Size: 560.00mm x 18.00mm (22” x 0.7”)
- Power: 25.2 watts, constant current, no resistors
- LEDs: 48 diodes Samsung LM561C top bin
- CRI: 80 (S6 bin)
- LED Color Temperature: 3000°K, 3500K, 4000°K, 5000°K
- Efficacy: 161 – 212 lm/w
- Power Consumption: 21.84 to 25.41 watts
- Operating Current (If): 1050 mA
- Operating Voltage (Vf): 20.8 to 24.2 Vdc
- Max. Current Rating: 1200 mA
- Cost: $13.76/board
These builds offer to spread the light strips throughout the whole grow area. Their lumen output is more directional @ 120° then conventional HPS/MH bulbs @ 360° (even with the best reflector, you are still losing 5% of the reflected light)
Comparative Cost Analysis:
- (1x) Quantum Board (288 diodes/board) power: 151.2 watts = $75
- (3x) SolStrip Board (96 diodes/board) power: 151.2 watts = $60
- (6x) LT-H562D Board (48 diodes/board) power: 151.2 watts = $83
All specs were calculated from the Samsung LM561c diode documentation, board layout, and manufactures documentation. This is all theoretical. Because of this, I’m running their operating specs close to a driver spec giving a fair display of the capability of all 3 boards. It is not ideal to run these boards at 100% power as it may damage the boards after a time. If you are operating these boards with a lower load these lights actually have a higher lm/w anyway so you don’t feel you have to crank it to get good results (Efficacy, in the specs above)
But after talking with Mr. @Baudelaire on the customizability, versatility, coverage, and affordability of the SolStrip. I was sold! 3x SolStrip boards will do the trick for a 150 watt system that can output up to a 400w HPS equivalent. The LED system will operate at a 1/3rd of the cost than a standard HPS.
The region between 400 nm and 700 nm is what plants use to drive photosynthesis is typically referred to as Photosynthetically Active Radiation (PAR)
The HPS is struggling to provide within plant absorption peaks for photosynthesis (PAR). Most of the HPS spectrum is in the plants low PAR range. However, a deHPS is 10-15% increase in spectrum than a standard HPS system and produces slightly more towards the reds, but the majority of all HPS are green/yellow spectrum light. The plant can use any spectrum light however at different efficiencies. The red light is easier to photosynthesize.
I chose to utilize 2x 3500K CRI 80 and 1x 4000K CRI 90 for my build.
I also made two graphs to represent the spectrum covered between the 2 boards. You can see the overall spectrum produced is following the plant absorption chart above. Ultimately providing a huge boost in spectrum efficiency.
I believe this combination will offer the fullest spectrum closest to sunlight. Notice how the 4000K board has a CRI of 90. This makes the spectrum have minor differences compared to a 4000K board with a CRI of 80.
Mean Well HLG-150H-24A LED Driver:
The specifications tells us all the information we need to select a driver with the highest efficiency. I’ve chosen a remote ballast to keep heat down and to offer access to the ballast without entering tent. I wanted dimming capabilities since this light will be for vegetative growth of seeds, clones, and mothers.
For my needs, I decided to use Mean Well HGL-150H-24A LED driver as all of their drivers are documented technically and offer the features I wanted. It meets all requirements for 3 SolStrips.
Note: If I had chosen the qb288 board, I would use the HGL-150H-54A LED driver
Note: If I had chosen the LT-H562D boards, I would use the HGL-120H-C1050A LED driver
So we are going to play a matching game between the specs of the LEDs and Driver.
Total watts of 151.2w for all 3 boards matches the drivers’ rated power of 151.2w (yellow).
• Amps x Volts = Watts | 6.3A x 24Vdc = 151.2w
Total Operating Current of 6.3A for all 3 boards matches the drivers’ rated current of 6.3A (green)
• Watts / Volts = Amps | 151.2w / 24Vcd = 6.3A
Total Voltage of 24v for all 3 boards (wired in parallel) matches the drivers’ DC voltage of 24v (red)
• Watts / Amps = Volts | 151.2w / 6.3A = 24Vcd
Now to figure out our efficiency
Using the graph above from the manufacture we can now see that our setup running wide open has a 92% efficiency running on 115Vac (from the wall). But this is on the 48v model, and I am using the 24v which loses 1% efficiency according to the drivers’ efficiency ratings per model. So we come in at 91% efficiency (Which is pretty darn good!)
Now we will calculate the minimum diming capabilities and where the efficiency range is for this setup.
We will make our range by taking the lowest voltage on the driver range and highest voltage on the LED circuit. Then we do the same for the Current (Amps) to give our actual systems’ operation range.
Systems Operating Voltage range | 22Vdc to 24Vdc = 138.6 watts to 151.2 watts
Systems Operating Current range | 3.8A to 6A = 91.2 watts to 151.2 watts
Maximum Operating range | 24Vdc x 6.3A = 151.2 watts
Minimum Operating range | 22Vdc x 3.8A = 83.6 watts
Maximum Operating Load | 151.2 watts / 151.2 watts = 1.00 = 100%
Recommended Max Load | 144 watts / 151.2 watts = 0.95 = 95%
Recommended Min Load | 91.2 watts / 151.2 watts = 0.60 = 60%
Minimum Operating Load | 83.6 watts / 151.2 watts = 0.55 = 55%
So now we see that we will be staying at the 90 to 91% efficiency on 115Vac (taking into the 1% loss noted above) The minimum dimmer settings on this unit for this system keeps it from going too low.
Lumen per Watt and System Efficiency
Looking at the diagram above, we can calculate how much current and volts this board will be running at for max power.
Each LM561c Diode = 200mA @ 3v MAX
96 Board Layout = 12 parallel circuits of 8 series circuits
We can stack volts by wiring in Series | 3 volts x 8 per series = 24 volts MAX
We can stack amps by wiring in Parallel | 200 mA x 12 per parallel = 2400 mA MAX
MAX Operating mA @ v for each diode on board with HLG-150H-24A Driver |
Driver max current 6.3A / 3 boards = 2.1A per board
2.1 A / 12 Parallel circuits = 0.175A = 175mA @ 3v
MIN Operating mA @ v for each diode on board with HLG-150H-24A Driver |
Driver min current 3.8A / 3 boards = 1.27A per board
1.27A / 12 Parallel circuits = 0.106A = 106mA @ 2.75v
Each Diode operating range for this system | 106mA @ 2.75v to 175mA @ 3v
Each Diode operating range for this system | 0.2915 watts to 0.525 watts
But how do we actually know the Luminous Efficacy?
Luminous Flux is represented as Φv
The LM561c diode with a CCT of 3500 @ CRI 80 has an average luminous flux of 36Φv. As you can see our luminous flux increases based on a percentage when our forward current increases. This means if each diode is getting 106mA of power, the luminous flux range increases to 54Φv, however if each diode is getting 175mA of power the luminous flux range increases to 90Φv by using the graph above we can calculating lumen per watt for this systems operation ranges.
36Φv x 100% = 36Φv @ 65mA (33% power) (Samsung testing current)
36Φv x 150% = 54Φv @ 106mA (53% power)
36Φv x 250% = 90Φv @ 175mA (88% power)
36Φv x 275% = 99Φv @ 200mA (100% Power)
(Maximum power the diode is capable of 200mA @ 3v)
Relative Luminous Flux / Watts = Lumens per Watt | 99Φv / 0.6w = 165 lumen per watt
(This is the standard Samsung testing done 65mA @ 2.75v)
Relative Luminous Flux / Watts = Lumens per Watt | 36Φv / 0.1787w = 201.4 lumen per watt
(Our LEDs system operating range lumens per watt)
Relative Luminous Flux / Watts = Lumens per Watt | 54Φv / 0.2915w = 185.2 lumen per watt
Relative Luminous Flux / Watts = Lumens per Watt | 90Φv / 0.525w = 171.4 lumen per watt
Our SolStrip LED system lumen per watt average | 171.4 to 185.2 = 178 lumen per watt average
Lumens @ 100% System power(max) | 151.2 watts x 171.4 lumens per watt = 25916 Total Lumens
Lumens @ 55% System power(min) | 83.6 watts x 185.2 lumens per watt = 15483 Total Lumens
Compared to HPS (w/plain bulb)
HPS 400w | 400 watts x 65 lumens per watt = 26000 Total Lumens
HPS 250w | 250 watts x 65 lumens per watt = 16250 Total Lumens
This theoretically is an adjustable LED system that can output 250w hps to 400w hps equivalent. Also cost a little over 1/3 to run compared to the HPS (w/plain bulb)
Lowest LED setting compared to 250w HPS | 83.6 watts / 250 watts = 0.33 = 33% cost to run
Highest LED setting compared to 400w HPS | 151.2 watts / 400 watts = 0.38 = 38% cost to run
LED efficiency compared to HPS (w/plain bulb) efficiency | 178 lumen per watt / 65 lumen per watt = 2.74 = 274%
LED efficiency compared to HPS (w/grow bulb) efficiency | 178 lumen per watt / 95 lumen per watt = 1.87 = 187%
LED system is 274% more efficient than HPS (plain bulb)
LED system is 187% more efficient that HPS (grow bulb)
Outlet to Lumen: Wiring explained
Lets check the systems load on the houses’ circuits, and verify that our AC power source is suitable.
This is the standard in houses. And a good rule of thumb is if its 15 amps then only run 12 amps
(80% Total AC Load)
AC Load on House Circuit | 1.7A / 15A = 0.11 = 11%
It has a minimal drain on the house circuit. Which is desired since more than likely pumps, heaters, and fans are going to be plugged in on the same circuit
It does state 4 units (drivers) maximum on one circuit. This is to prevent any over loads that may occur when other electrical devices are using the same circuit.
Let us start at the wiring for AC plug for the system and work our way to the SolStrip boards. Our whole goal is to make sure everything is properly rated for our system and is built to last. Please do not take short cuts in wiring, it will lead to an electrical fire.
Since this LED system will be on a 15 amps circuit running 120 volts, the appropriate grounded plug has been chosen. UL Rated for 15 amps and 125 volts
I used a 9 ft power cord. 18 AWG should be good for this driver and power load, but I decided to use 16 AWG and this is also UL rated for 300 volts. I want to point out the drivers wires are at 18 AWG, because of that we base our system off of the smaller wire in the circuit.
Take apart the plug and string the power cord through the housing of the plug. Slide it down a bit so it is not in the way when we are striping the wires. Strip the power cord about 1 ½ inches, remove the insulation, and then strip the 3 wire about ½ inch.
WHITE wire to the SILVER neutral screw
BLACK Wire to the BRASS hot / live screw
GREEN wire to the GREEN grounding screw
Slightly bend the wire and put it in the wire vice and screw tight. Make sure you are clamping on the bare wire and not the plastic insulation. Do this with all 3 wires. Next slide the housing for the plug and screw together, then screw the clamp on the plug so the cord is secure. We have one end done!
I don't solder to often but I do have some experience. I gathered up some supplies for this build, not everything I used shown in the picture but you get the gist of it.
So looking at the AC side (input) of the driver, the wires are labeled by color according to ground / live / neural (, ACL ACN) These wire ends come pre-tinned (wicked with solder) from the driver, so I cut them off and re-striped them so I could inter mesh them with the corresponding wire. As you can see I don't have the nicest solder work, but the solder is completely wicked through and has a very strong connection.
Now just match function of each wire from the power cord to the driver.
WHITE (neutral) ---> BLUE (ACN)
BLACK (hot/live) ---> BROWN (ACL)
GREEN (ground) ---> GREEN ()
Next I extended the DC side (output) wire. I used a 4 foot power cord with 2 conductor wires. I matched the driver red + (positive) wire to the white wire and the black - (negative) wire to the black wire.
WHITE (positive + ) ---> RED ( + )
BLACK (negative - ) ---> BLACK ( - )
I shrink wrap my wire connection to give a nice tight seal. I also put dielectric grease in the tube before shrinking it to protect it from moisture. Its certainly not necessary but it provide extra protection plus it looks very neat.
To finish off the driver side of the light I will be wiring in a waterproof quick connect. This will be convenient with the installation within the tent. Same as before wires are soldered together then shrink wrapped.
Space Age Aluminum Frame
I decide that the frame would be constructed out of aluminum for the add benefits of; low profile, higher heat conductivity, and it just looks cool . I'm not a fabricator, however I was able to build a frame for these LED strips by using some tools I had on hand (Sawsall, Hand Drill, Orbital Sander) Not the best tools but just enough to get the job done.
I picked up some aluminum at my local hardware store to make a frame. Cutting and drilling aluminum is very doable with some metal bits and blades. I also sanded all the aluminum to make it smooth once again after drilling and cutting it. Then I used M3 x 8 screws to secure everything together. I picked up some washers at the hardware store for each screw. Everything came together square and the frame is very rigid.
I used 18 AWG red and black wires. Since I want to wire these board in parallel I made my own parallel wires for the system. I soldered each junction and shrink wrapped them. I also tinned the tips of the wires so when they slide in and out of the SolStrip they will not fray.
The heat sinks (SolSinks pre-tapped from @Baudelaire) are attached by more M3 screws and washers to secure into place. We can move, add, or remove the lights as needed. I attached the wires to the frame with zip ties for lack of a better (permanent) solution. (I might add two more strips to this unit so I would rewire it anyway)
I generously apply lots of super lube (silicon heat compound) between the heat sink and the SolStrip then tighten into place with some M3 screws. Then slide in the wires into the boards.
Now we finish of the light by wiring in the other side of the waterproof quick connect. Yep you got it...soldered wires together and then shrink wrapped. (just makes it look so neat)
This was at the lowest setting, it was the only way I could see the frame in the picture. Any higher the frame was blacked out.
LED 150w SolStrip X1 Light System
- Light Bar Size: 18in x 16in x 1in (457mm x 406mm x 25mm)
- Light Bar Weight: 2.69 lbs (1219 grams)
- Power Range: 85w - 150w
- LEDs: 288 diodes Samsung LM561C top bin
- Spectrum: 2x 3500K CRI 80 / 1x 4000K CRI 90
- Max output: 26,000 lumens
- Lumen Efficacy: 171 - 185 lu/w
- Viewing Angle: 120°
- Power Consumption: 83.6 to 151.2 W
- Operating Current (If): 3800 to 6300 mA
- Operating Voltage (Vf): 22 to 24 Vdc
- Max. Current Rating: 7200 mA
- Remote Ballast - Mean Well HLG-150H-24A
- Adjustable Voltage and Current on Ballast
- 10 foot AC power cord
- 5 foot DC cord w/ water resistant quick connect
- Cost to build: $175 for whole system (driver incl.)
Last Edited: 12/14/2017