GrowLightResearch
Well-Known Member
This past weekend I threw together a test fixture to test the newish Bridgelux Gen 2 strips.
I collected data on currents, temperature, and PPFD.
6 Bridgelux BXEB-L0560Z-30E2000-C-B3 strips. $7.36 ea.
Driver: HLG-185H-54A, Constant current ≈$50
3 pair of strips with two strips wired in series
Vf @ 500mA (Sets Measured Individually)
37.94v
37.86v
37.77v
The 3 pairs were then wired in parallel
No heatsink needed even at max current
Temperature at 1 Amp ≈ 42° C
Parallel Vf = 39.0v @ ≈1 Amp
Parallel Vf = 39.6v @ ≈1.4 Amp (max)
The currents in all three sets of strips were periodically measured.
Currents in the strips were unbalanced due to the parallel wiring.
Each pair had a 0.010Ω 1% resistor wired in series to it's current supply
The resistors voltage drop were measured and converted to current.
The yellow current measurement were supposed to be around an amp. But instead varied 15-28% becasue of the unbalanced loads.
Yellow 965 mA to 1245 mA, Vf= 36.06v
Blue 12238 mA to 1523 mA, Vf= 36.60v
=============================================================================
The test floor of a Gorilla LIte tent: 30" x 24".
Fixture: 22" x 24"
I will be adding a seventh strip when I get a new driver to run all the strips in series.
The unbalanced strip currents did not cause major problems with uniformity.
The unbalance load will put stress on some of the strips.
The forward voltage of these strips are rather good.
The Vf of each individual strips @500mA are:18.55v, 18.88v, 18.89v, 18.89v, 18.92v, 18.94v.
I was surprised to find nearly 30% differences in strip current.
The thing is they all look good, the PPFD measurements are good. At distances less than 36" the measured irradiance had greater fluctuations.
=====================================================================
PPFD was measured at 36” with a US StellarNet Blue Wave Spectrometer.
The current was adjusted to get the values around 100µmol/m²/s
The actual measured values were normalized to 100 in order to compare them to the simulated values which were also normalized to 100 max.
The yellow strips show the relative location of the strips to the sensor measuring the irradiance. The sensor was moved inch by inch along the line shown above and below (simulator screen shot).
========================================================================
PPFD was simulated at 36”
This is an app I have been working on since August 2016. It simulates the uniformity of grow lighting. Here we can see it works fairly well. The simulated values nearly match the measured.
I collected data on currents, temperature, and PPFD.
6 Bridgelux BXEB-L0560Z-30E2000-C-B3 strips. $7.36 ea.
Driver: HLG-185H-54A, Constant current ≈$50
3 pair of strips with two strips wired in series
Vf @ 500mA (Sets Measured Individually)
37.94v
37.86v
37.77v
The 3 pairs were then wired in parallel
No heatsink needed even at max current
Temperature at 1 Amp ≈ 42° C
Parallel Vf = 39.0v @ ≈1 Amp
Parallel Vf = 39.6v @ ≈1.4 Amp (max)
The currents in all three sets of strips were periodically measured.
Currents in the strips were unbalanced due to the parallel wiring.
Each pair had a 0.010Ω 1% resistor wired in series to it's current supply
The resistors voltage drop were measured and converted to current.
The yellow current measurement were supposed to be around an amp. But instead varied 15-28% becasue of the unbalanced loads.
Yellow 965 mA to 1245 mA, Vf= 36.06v
Blue 12238 mA to 1523 mA, Vf= 36.60v
=============================================================================
The test floor of a Gorilla LIte tent: 30" x 24".
Fixture: 22" x 24"
I will be adding a seventh strip when I get a new driver to run all the strips in series.
The unbalanced strip currents did not cause major problems with uniformity.
The unbalance load will put stress on some of the strips.
The forward voltage of these strips are rather good.
The Vf of each individual strips @500mA are:18.55v, 18.88v, 18.89v, 18.89v, 18.92v, 18.94v.
I was surprised to find nearly 30% differences in strip current.
The thing is they all look good, the PPFD measurements are good. At distances less than 36" the measured irradiance had greater fluctuations.
=====================================================================
PPFD was measured at 36” with a US StellarNet Blue Wave Spectrometer.
The current was adjusted to get the values around 100µmol/m²/s
The actual measured values were normalized to 100 in order to compare them to the simulated values which were also normalized to 100 max.
The yellow strips show the relative location of the strips to the sensor measuring the irradiance. The sensor was moved inch by inch along the line shown above and below (simulator screen shot).
========================================================================
PPFD was simulated at 36”
This is an app I have been working on since August 2016. It simulates the uniformity of grow lighting. Here we can see it works fairly well. The simulated values nearly match the measured.
Last edited:
