Here is shown how a XHP70.2 is DD driven I would not recommend it
left original GT calculation;
middle 50mOhm resistor mod pushing the original driver over the rated specs, Input capacitors should be doubled
regulation can break down as the minimum ripple not met with 10uH Inductor,
right my driver with proper sized upgraded parts
New generation of MOSFETs with 1/3 the conduction and half the switching losses,
2.2uH for proper ripple current and less losses on it,
reduced voltage divider to get the sense resistor smaller,
better diode 20A instead 3A
Its possible to push the original to 5 max 6A, but changing R14 to 12kOhms and adding at least 20-30uF input capacitors
I would no go beyond 7A with the LED its not worth it
Hallo, ich brauche einen Treiber für die BLF GT —XHP 70.2—.Hat noch jemand einen zu verkaufen
.Ich komme auch aus Deutschland (Hessen).Liebe Grüße Andy
But the current is limited always the same, so on 6V the output would be needed to use 2 buck circuits on one board I made such a layout, but its not cheap to make with 26€
I’ll try to find out how to 4S the emitters with the stock 1S MCPCB, and get myself a 4S tailcap. You do sell it a 4S tailcap if I understand? Or is it only for the MF01/02?
I don’t think that price sounds unreasonable for a driver like that. I would be interested in a driver for 5s, 6s, 8s. Higher voltage is fine for the projects I have in mind. Some of the light builds I am considering are as high as 14s.
I have added a link to to this thread in my new BLFGT video as well. If I had know about this driver before I would have included it as an option in the video.
Powerful buck for 36V COB is planned with up to 12S and 5-6A output, above we have to consider how to get proper input MLCCs not cheap in 100V,
also LDOs in more than 60V and fast enough MOSFET above 50(60V rated) is an issue
Nothing speaks against Endermans quad buck driver design I made with just 2-4 circuits equipped, if mounted flsat to a heatsink as it is designed
So I found today a very odd problem with the LM3409 Buck driver
Its related to the voltage regulator, it seems in this case 10 Ohms resistor was to big get the LDO in a stable regulation,
it had a voltage drop over C1 from 16 to 10.5V, which is very bad, the resistor should decouple battery and LDO input voltage from spikes,
but the battery side looked pretty clean while the LDO side had every 20ms a big drop from the LDO probably resetting
output voltage had about 1.4V ripple on about 70% of the ramping very low working fine, then at a level it started
resulting in an unstable max. current as the current control voltage was not stable at 5V
Replacing the LDO and trying to solve probably capacitor issues replacing them as well did not help
I lowered R1 from 10 to 4.7Ohms this cleared all ripple on the LDOs input and output side
I recommend if you can solder SMD to do this on all drivers add a 10 Ohms resistor above R1
Interested in one of the next-gen super high current buck drivers (like the CFT-90 driver for the BLF GT). Intended application is driving 7 ~6v Nichia 144 LEDs in parallel, from either 4s or 2s2p (which would work best?) in an SRK style light. If there’s a driver in this series that fits the bill, please put me down for it.
It’s hard to say. The D4 bin has a tolerance of plus or minus 7%. Assuming you had two that put out the same lumens at the same amperage, you’d need a lux meter that read the different color temps the same. Most of the inexpensive lux meters seem to be more sensitive to CW.
