Results 1 to 9 of 9

Thread: Help selecting resistors and tri led, cree xp l

  1. #1

    Default Help selecting resistors and tri led, cree xp l

    For example, I want to use all red cree tri led, tcss says
    Red Cree Part# XPEBRD-L1-0000-00901
    80.6 Minimum Luminous Flux @ 350mA
    Forward Voltage @1000mA = 2.59v

    What does the 80.6 luminous Flux mean. I assume I put 1000mah and 2.59v into my calculator and get three resistors wiring them parallel?

    Also looking at the cree xp l, tcss says

    Cree Part# XPLAWT-00-0000-0000V5051 6200K Cool White
    440 Minimum Luminous Flux @ 1050mA
    620 Minimum Luminous Flux @ 1500mA
    776 Minimum Luminous Flux @ 2000mA
    1034 Minimum Luminous Flux @ 3000mA
    Forward Voltage 2.95-3.25

    Totally lost on what to use for mah and forward voltage in this one.

    Can someone please help, just planning on stunt blades

  2. #2
    Sith Warrior darth_chasm's Avatar
    Join Date
    May 2015
    Location
    United States
    Posts
    1,756
    Blog Entries
    2

    Default

    Luminous flux is the measurement of perceived light. Reds will tend to be lower than other colors because the human eye does not perceive reds as bright. That's not to say the LEDs aren't bright, they're quite the opposite.

    mAh is ampere-hour and is in regards to battery capacity/runtime. mA is milliamperes and is in regards to the current a component can accept. Its good to know this difference.

    Yes, the numbers you mentioned are the ones you use for your resistance calculation. You'll also need the third part of that equation which will be your battery supply voltage.

  3. #3

    Default

    This should help you figure things out:

    http://forums.thecustomsabershop.com...e-to-Ohm-s-Law
    TCSS MODERATOR
    All n00bs READ these first (PLEASE)!!!:
    1. Forum Guidelines
    2. FJK’s “Down and Dirty” guide to Ohm’s Law

    "Yeah, yeah, I've heard it all before... you want blindingly bright, super loud, running 1138 blinkies off of the cheapest sound card you can find AND you want all of it to run on a battery the size of a dime, and run for a very, VERY long time. That one cracks me up every time..."
    My email: fjk_tcss@yahoo.com

  4. #4

    Default

    Quote Originally Posted by Forgetful Jedi Knight View Post
    This should help you figure things out:

    http://forums.thecustomsabershop.com...e-to-Ohm-s-Law
    I know about ohms law, what I do not know is why there is a range and different Luminous Flux on the white cree. Is it so I can choose how bright I want it or? Also how do I know what forward voltage to plug into calculator when it gives me a range for the forward voltage as well.

    I know how to select single leds and figure it out but not this when it gives me different options and ranges for forward voltage

  5. #5

    Default

    For the Cree XP-L, you pick the current you will be running the LED at and the rest of the corresponding values are what you will get. The Vf is a relative thing - the lower the current, use the lower end of the Vf range, and the more current, use the higher end of the range.
    TCSS MODERATOR
    All n00bs READ these first (PLEASE)!!!:
    1. Forum Guidelines
    2. FJK’s “Down and Dirty” guide to Ohm’s Law

    "Yeah, yeah, I've heard it all before... you want blindingly bright, super loud, running 1138 blinkies off of the cheapest sound card you can find AND you want all of it to run on a battery the size of a dime, and run for a very, VERY long time. That one cracks me up every time..."
    My email: fjk_tcss@yahoo.com

  6. #6

    Default

    Quote Originally Posted by Forgetful Jedi Knight View Post
    For the Cree XP-L, you pick the current you will be running the LED at and the rest of the corresponding values are what you will get. The Vf is a relative thing - the lower the current, use the lower end of the Vf range, and the more current, use the higher end of the range.
    So if I chose to run at 1000mah on a 3.7 v battery I would need a 1 ohm resistor correct?

    I take it that if u choose a lower mah to run at you will have a less bright led and longer life?

  7. #7

    Default

    Quote Originally Posted by Sidious_999 View Post
    So if I chose to run at 1000mah on a 3.7 v battery I would need a 1 ohm resistor correct?

    I take it that if u choose a lower mah to run at you will have a less bright led and longer life?
    Here, just use this.

    http://led.linear1.org/1led.wiz

  8. #8

    Default

    Quote Originally Posted by Sidious_999 View Post
    So if I chose to run at 1000mah on a 3.7 v battery I would need a 1 ohm resistor correct?

    I take it that if u choose a lower mah to run at you will have a less bright led and longer life?
    Yes, both are correct. Using online calculators will also tend to give you overestimated results, which might even dim your blade more, which is why I recommend doing the math yourself, which you are capable of doing.
    TCSS MODERATOR
    All n00bs READ these first (PLEASE)!!!:
    1. Forum Guidelines
    2. FJK’s “Down and Dirty” guide to Ohm’s Law

    "Yeah, yeah, I've heard it all before... you want blindingly bright, super loud, running 1138 blinkies off of the cheapest sound card you can find AND you want all of it to run on a battery the size of a dime, and run for a very, VERY long time. That one cracks me up every time..."
    My email: fjk_tcss@yahoo.com

  9. #9

    Default

    Quote Originally Posted by jt_trouble View Post
    Here, just use this.

    http://led.linear1.org/1led.wiz
    That's the one I used just wanted to make sure I was reading stuff right and wanted to double check

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •