QB 304 driver questions

Discussion in 'Lighting' started by degrassi2, Aug 25, 2017.

  1. I was able to understand how to use forward voltage to figure out which supply i needed for COBs but I feel rather confused with the QBs. I have a bunch of QB304s (over 4). HLG's website says to use the HLG-240H-C2100 250 watts (59-119v) or HLG-320H-C2800 320 watts (57-114v) to connect 4 of these lights together.

    Max current per QB304 is 1600 mA. Max FV per diode is 200mA. I think the site is trying to tell me to run these in parallel.
    QB304 Board Guide

    My questions:

    Should i without a doubt use parallel wiring only? - I assume i need to in order to keep each board below the 1600mA max because in parallel the mA are divided up between the boards.

    I'm looking at HLG's specification chart. Does "voltage max Vf" mean Forward voltage?

    If using the 320H driver would i be able to get the maximum lumens out of 4 lights? What setup of drivers should i use to get the best quality of lights out of the lights. I can purchase any number of drivers... not that i want to though.
  2. The HLG 240h c2100a is what I use with the qb260 with 2 boards wired in series.

    You're much better off using the 320 for 4 boards. You'd be running 4 boards at half the power they could put out if you used a 240.

    If you use a constant current driver you wire in series.

    I think using 2 drivers for 4 boards is a better approach. Get 2 240h c2100a drivers for each two boards in your fixture. If you get the heatsink that goes with the qb260 it has a higher capacity for wattage then the 4 board fixture. Up to 285 watts. You can get more out of 4 boards with 2 drivers and 2 heatsinks.

    You can spread the lights wider for better coverage and run them at different heights if you want. Two drivers is twice as reliable.
    • Like Like x 1
  3. T bone is on the money

    Sent from my SM-G930W8 using Tapatalk
    • Like Like x 1
  4. I havn't logged back in since the question. Thank you for the reply.
  5. I'm not concerned with having the lights at different heights. 8 Lights will go in 1 tent. If one 320h will provide the same lumens as two 240H running 4 total QB304s then I want to go with the 320H for simplicity. I have already purchased a few of their heatsinks Slate 4 Quad Plate
    In their image of the heatsink it shows a HLG480H c2100A driver which at the time added to my confusion. I will definitely use a 240H driver in another tent.

    At this point I have no plans or desires to purchase external dimmers and such. I don't wish to buy those tools that monitor exactly how many watts I'm pushing out. If possible I would like to turn up the amps "set it and forget it style." I will use the drivers dimmer knob eventually. I'm curious to know if i connected 4 lights to the 480Hc2100a and turned the drivers amperage all the way up, would it burn my lights out? I imagine that it would.
  6. The HLG 480h 2100a is what they use on the 550 at HLG. You can clearly see it in the review video.
    • Like Like x 1
  7. Geez, i forgot i watched this video last month during research. GUess i should just get that 480 since the heatsink is already designed to fit it.
    • Like Like x 1
  8. I assume you changed your stance on this with the info you gave me yesterday no? Just mling sure I'm not buying drivers that will only power my lights 50% or something. The math u gave me seems to add up so what's the final verdict? Worked late last few days so I'm ordering tonight instead. Thanks brother
  9. The missing piece of info is exactly which boards you bought? If you bought HLG qb304 boards then you need the 240h-c1050a driver for each two in series. If you bought the other alibaba sourced 304 boards you can use the 2100a since they are 54 volt boards.
    • Like Like x 1
  10. It's worse then that. They won't turn on with the 2100a driver if you did get the HLG qb304's. It can't make enough volts to turn them on by a long shot. It may be able to run one board.
  11. I'll double check what she said it was but I believe it indeed was 54 v boards. They are bot from hlg so we can assume they are those right ...I'll double check this in a bit. If they are 54 then the 2100 is what I'd need?
  12. What I have written down, going to verify this w the original email if possible, but here is what she said:
    PCB size 286*174*1.6mm
    Wattage: 49.2-136.8
    Voltage: 102.6-114v
    Amps: .48-1.2a
  13. The max amp rating is 1.2a or 1200mA. That's another reason why the 240h-c1050a is needed. See that voltage range? When you wire two in series it doubles to 220 volt range.
  14. Can you point me in th e right direction on how to wire them in series then with the 1050 by chance? I saw on hlg website ur 304 board project that popular drivers are indeed 1050 in series then it says for parallel and a bunch of drivers including the 240h c2100a. The lady I'm dealing w said the the 2100 works w them, "we sell many, the work no problems.

    Not denying u know ur shit cuz I see u are indeed the guru here of leds or at least why i have been reading but I'm just getting confused as to why they say in can work and u say no. Is it one of those cases where either will work or is the 2100 just not what I need. Thanks again my man appreciate your time
  15. You could wire it in parallel. It's just not typical. Those drivers are almost always wired in series. It's so common to do that with the qb260 I never even thought about parallel. Most constant current drivers are used because they supply the same current to a load in series and the voltage varies.

    The "Lady" you're dealing with is correct. Since the qb304 requires 1050mA if you wire two in parallel it creates a 2100mA load.

    This is how they are typically wires in series.

    Series wiring starts at about 17 minutes in.

    In parallel both boards would connect directly to the positive and negative outputs of the drivers.
    • Like Like x 1
  16. Sorry if I messed you up. I've never heard of wiring a qb260 with one of those 2100a drivers in parallel. I own two qb260's with 304 boards and they both use the 240h-c1050a driver in series.
    • Like Like x 1
  17. I didn't even realize that I recommended the 2100a in that first series of posts. That's for qb288's. I didn't even look at my own fixture. Cool thing is I guess they both work.
    • Like Like x 1
  18. No worries brother she said the same thing about series and parallel ..my last question would be is there a benefit of wiring the one way over the other at all?
  19. Not really. They used to always recommend series because it was claimed that series wiring protected leds from thermal runaway they were in danger of if one burnt out in parallel.

    You can google it and read about thermal runaway and wiring in series.

    Wiring them in parallel was the way to use cheaper drivers though so many people have been doing it for a long time now. It didn't make sense that it wouldn't work because if you look at the way the boards themselves are built there's already many strings of diodes wired in parallel on the boards.

    The boards are so bulletproof that wiring parallel there is little to no danger of thermal runaway. The common way to wire in parallel is to use a constant voltage driver like a 54 volt driver. In that case there's nothing keeping the current of the driver from maxing out. Modern cob style leds have proven to be fairly safe from thermal runaway even on constant voltage drivers wired in parallel. That's the only way that 4 qb132's works on an LRS 350-36. It will put out enough power to burn up the boards. It's the 36 volt contant voltage keeping them in check.
    • Like Like x 1
  20. You're using a constant current driver if you use the 2100ma so it will prevent thermal runaway by not letting the current go above that. Completely safe to wire that in parallel.
    • Like Like x 1

Share This Page