LED selections & drivers

Discussion in 'The Projects Forum' started by Rainbow Clouds, Jan 19, 2015.

  1. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015
    7
    1
    Hi all,


    I have no background in EE however i'm facing some problems with a lighting design and would like to seek your professional advice on selecting LEDs & driver.


    Background


    Lighting Design - Decorative Lighting (LED) - not particular about lumen output however estimate will be 300lm-900lm. (because it is a decorative lighting, it is not as important as it is more to aesthetic & ambient lighting design.)


    LED - COB i'm trying to select COB as it would be easier for me not dealing with PCB boards however i'm open to your opinions and advice about this.


    COB options preselection


    COB that i have done pre-selection : CREE CXA 1304, LUXEON 1202, LUXEON 1202s for this project, i did this selection based on the few criteria of the sizes and lm output, however i'm not too certain of the applicable differences here and i can hardly understand the datasheet comprehensively.


    Drivers


    My country AC: 240V

    So i assume that i might need to convert a 240V using a driver / ic driver to perhaps 9V (if based on CREE CXA1304), however (i'm not certain with LUXEON 1202, 1202s because i don't have basic to understand the datasheets because it is not directly stated)


    I would like to learn the differences between selecting a driver vs a IC driver. I'm not sure when should i use which.

    How should i pair the drivers with the LEDs.


    Lighting Design


    If you need the lighting specs that i'm aiming for, it's pretty hard for me to say what i wanted if you ask how many volts or watts you want to achieve, however the only way to answer this with my limited knowledge in EE is this is definitely not a high power LED project, however need to achieve quality light source, if the DC can fit the normal standards where it is convenient to use by anyone etc 12 V? I'm not sure if i'm saying the right things either.


    Hope to get some help and advice.

    Please find attached Datasheet links.


    http://www.philipslumileds.com/products/luxeon-cob

    http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-NonDirectional/XLamp-CXA1304




    Thank you in advance. :)
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,232
    Maybe I can stir up some ideas.

    1000 lumens is about as bright as a 75 watt light bulb. Do you need it this bright?
    This is fairly high for a LED so it will need to be mounted on a heat sink to get rid of the heat.
    If you don't have experience buying a LED driver is the best bet. Otherwise you need to build circuits.
    In order to find a driver the voltage and current of the LED is needed first.
    So if the brightness you want is right we can look for a driver.
     
  3. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    First.. LEDs need to be fed from a constant current source. Which is what most LED drivers are.

    To pick a driver you simply need to know the min/max forward voltage (Vf) of the LED and the amount of current it is rated for (or how much you want to run it at).
    Then you simply pick a driver with a DC output voltage rating less than the min and greater than the max Vf of the LED.
    Then ensure it has a current output rating equal to or less than the amount of current you need.


    I LOVE Meanwell drivers and will not recommend anything else as they are simply the best. The cheap Chinese stuff on ebay,etc.. is hit or miss and can work just fine or become a fireball.

    Example..
    If I have an LED with a Vf of 30-36V and a current rating of 1000mA (or 1 amp) I would pick a Meanwell LPF-40-42
    http://www.meanwell.com/webapp/product/search.aspx?prod=LPF-40
    If I wanted it to be dimmable I would simply pick their LPF-40-42D driver and pick up a 100k potentiometer.

    Their LDD series of drivers is great for when you already have a DC power supply greater than the Vf and just need to turn it into a constant current source.

    an IC obviously requires you to have a circuit board and will require other components too.
    An IC would be used when you are making hundreds/thousands of LED lights.
    Enclosed LED drivers (like meanwell LPF/LDD,etc...) are great for just a couple custom fixtures.

    And lastly don't forget heatsinking.. All "high power" LEDs require decent heatsinking or they will overheat.
    I find a cheap Duron CPU heatsink w/fan works great for LEDs up to 50 watts.
     
  4. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015
    7
    1
    Hey! Thanks guys for the prompt reply. @ronv @mcgyvr
    Appreciate it very much!

    Okay hmmm ... now i have a better understanding.
    I guess i shall try a external driver for a start. (since i will not need circuit board)

    I think i will be aiming at just 500lm - 700lm.
    CCT: 3000k
    Usage Indoor: Does not require high IP ratings.
    Will go for quality driver: willing to pay for longer life spent & safety! =) (thanks for recommending Meanwell will check that out)

    Voltage input: 240 V.
    i will be trying out both cree CXA 1304 & phillips 1202S.
    I have attached some images below.
    How do i start after i have decided on the output lumen & LED type.
    I realize the CREE LED info & Phillips looks different. (I'm rather confuse)

    Thanks in advance!
     
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    You pick a part number that meets all your requirements (color temp/lumen output,etc...).. find its Vf and current requirements and find a suitable driver and suitable heatsink and optics if needed. Buy the parts..mount/wire it up and voila.
    Note!!! DO NOT look directly at high power LEDs.. They can blind you quickly/permanently.
     
  6. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,232
    Can you post a link to the 2 you like. We need a little more of the specs.
    But having said that my bet is they are not the same so they will need different drivers.
    Are you aware that they will need to be mounted on a heat sink?
     
  7. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015
    7
    1
    Thanks @mcgyvr
    Hi @ronv

    Here's the datasheet link to the two LED.
    http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Arrays-NonDirectional/XLamp-CXA1304
    http://www.philipslumileds.com/products/luxeon-cob (1202 / 1202s)

    Yup, i'm aware that i should mount it on a heatsink. =)
    May be i'm just going to use some aluminium extrusion to mount it with, i'm assuming that mine is not that high heat or high power. (correct me if i'm wrong).
    Planning to get these parts from Mouser online shop.

    For the cree there's this product option:
    Product options 9-V, 18-V, 37-V, high-CRI, in which i don't quite understand, does that mean that with any driver i buy it can be drive at 9V, 18v, 37v or this is depending on the driver i get ?
    - Does that mean if i select the lower VF of the LED product means the energy consumption is better ?


    Specs Aim / objective:
    Output lm : 500lm or lower
    CCT: 2700K / 3000K

    Cree:
    http://my.mouser.com/ProductDetail/...4Prknbu83yx7PpVbn5Yo/qi1d56QrVbHWudIlg3SE/A==

    http://my.mouser.com/Optoelectronic.../_/N-8usfj?P=1yzxcyd&Keyword=CXA+1304&FS=True
    (just realize it's not that simple buying a LED, now i'm really confuse with the ranges)

    Phillips:
    http://my.mouser.com/ProductDetail/Philips-Lumileds/L2C1-2790120206A00/?qs=6pHq9bjOlal7L0S1XwMTEQ==

    Thank you in advance! =)
     
  8. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,232
    The good news is they at least overlap. :D
    You should be able to use the 37 volt Cree and the 35.5 volt Phillips at 200 ma.
    Usually the drivers will have a range of voltages at a current. Like 25 to 48 volts @ 200 ma.
    All we need to do is find one.
     
  9. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015
    7
    1
    @ronv

    Oww Thanks !!! :):D
    Just for basic understanding.
    Those 9vf, 18vf, 37vf are basically differentiated for driver purposes?
     
  10. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,281
    1,232
  11. Rainbow Clouds

    Thread Starter New Member

    Jan 19, 2015
    7
    1
    Thanks @ronv!
    I will check it out!

    Thank you all for your help & guidance!
     
Loading...