I have this SST-300 High-power LED which requires 10A and 12-14V as described in the product characteristics. The product is suggesting with its own power supply as well as its own constant current led driver which comes as a separate unit from the supply. however, i would like to make my own power supply system for this one, for budget porpuses. So im thinking of buying one of those ‘led strip supply’ of 10A and 12V which gives a 120w (lesser than the maximum led power which is 150w) and make the current that comes from the supply even more stable and free of harmful spikes, using this “600w 8-16V 12V 24V to 12-60V 48V boost converter”, even for the price of losing some few watts. Should it work that way? there are any calculations i need to take in account? It will be nice to get your help. Thank you!
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\$\begingroup\$ What calculations could you take into account with equipment from AliExpress and no data sheets? \$\endgroup\$– Andy akaJul 30, 2019 at 13:47
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\$\begingroup\$ The 12V supply used directly with the LED will probably 'work well enough'. Either the LEDs will want less than I_Supply_max at 12V and so "just work. Or will try to draw more than 10A at 12V so need a small series R. At 10A every 0.1R will drop 1V so adding lead length may suffice. \$\endgroup\$– Russell McMahon ♦Jul 30, 2019 at 14:50
2 Answers
The cheapo converter posted in the question will pop its output caps at 10A, they won't handle the converter's ripple current. No way. Be careful with these cheap chinese items, the specs are usually fantasy. Especially the "LM2596" ones, they're usually counterfeit chips.
Wiring a cheap converter at the output of a low quality switching power supply increases risk of trouble, and converting the voltage twice means more losses than using a simple offline constant current LED driver.
So, let's use an all-in-one constant current driver. These have an allowable output voltage range, and this must include the voltage range of your LED. Actual output voltage is determined by the LED, but it must be within the range allowed by the driver.
Your LED has a Vf of 12-14V at its nominal current of 10A, so you can't use a driver than is limited to a max voltage of 12V in constant current mode.
Thus, a Meanwell HLG-150H-15 is a good fit. It delivers 10A constant current with an output voltage between 7.5V and 15V, which is what you need. Get the -B version if you want it dimmable. It is not expensive and it works.
You will also need a fan, and I'd definitely recommend a thermal shutdown sensor on the LED. Heatsinks and filters tend to clog up with dust over time.
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\$\begingroup\$ i found the datasheets of the power supply (google 's-120-12 datasheet') and i also got components names of the converter which are MBR20100 and 072N10N which both heatsinked, while the LM chip is "LM358 HLF108". in a brief look at the first two components's datasheets, it seems for me, that they can handle 12v at 10A, but of course, i need the answer from an expert. For the HLG-150H-15, i searched a bit for a price and the price range is still a bit high for me, although i can buy it anyway. so my question is if are there any imitations of this supply that are even more cheap than this one? \$\endgroup\$– meowcatJul 30, 2019 at 15:23
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\$\begingroup\$ Well, your power supply may work but 12V isn't the correct voltage and it is constant voltage, not constant current, so another converted is needed, which costs more and increases losses. Instead you can search for "AC-DC LED driver" or "offline LED driver" on aliexpress, you will find cheaper off-brand mains powered constant current drivers. Make sure the output voltage range includes the 12-14V range your LED requires, and that it can output the amps. \$\endgroup\$– bobfluxJul 30, 2019 at 15:56
The 12V supply used directly with the LED will probably 'work well enough'.
Either the LED will want less than I_Supply_max at 12V and so "just work.
or
The LED will try to draw more than 10A at 12V and so will need a small series R. At 10A every 0.1R will drop 1V so adding lead length may suffice.
