Results 1 to 7 of 7

Thread: resistor question

  1. #1

    Default resistor question

    Hi all, let me start by stating i'm a first time saber builder.

    I have purchased most everything i need and am in the process of final design.

    My question is about the resistor requirements for foc using onboard Pex.

    I have a pack of 7.4v Li-ion 1050mAh 14650 batteries

    a cf8

    a blue/royal blue/ white tri-cree (white for foc @ Forward Voltage @1000mA = 3.15v)

    I'm not sure that my understanding of the manual is correct. From page 39/40 i believe i need a 4.7ohm, 4.7w resistor for foc.

    Does this sound correct? What will my battery life be expected to be?

    Any and all info is appreciated!
    thanks,

  2. #2

    Default

    Resistor is correct. You're looking at about half an hour or so of runtime. You could bump up to a larger pack made with 18650 cells and get more runtime if you need, or else design your saber to allow easy swapping of battery packs.
    We all have to start somewhere. The journey is all the more impressive by our humble beginnings.

    http://led.linear1.org/1led.wiz for the lazy man's resistor calculator!
    http://forums.thecustomsabershop.com...e-to-Ohm-s-Law for getting resistor values the right way!

  3. #3

    Default

    hmm...... what is my best option for extending that run time? two 18650 wont fit......
    should i hack the board to run on 3v?

  4. #4

    Default

    That is another option. You could do the single-cell hack and use a single 18650 cell. Or a pair of 14650 cells wired in parallel. There are several options.
    We all have to start somewhere. The journey is all the more impressive by our humble beginnings.

    http://led.linear1.org/1led.wiz for the lazy man's resistor calculator!
    http://forums.thecustomsabershop.com...e-to-Ohm-s-Law for getting resistor values the right way!

  5. #5

    Default

    I have a pack of 14650 in series, i suppose i could change those over to parallel and double my ma to 2300ma @ 3.7v


    Assuming my new voltage supply of 3.7v i would need a 1ohm 2w resistor for foc. does this sound like a better setup?

  6. #6

    Default

    It would have a longer runtime with that setup.

    If you want maximum runtime with minimum space, http://www.thecustomsabershop.com/Pa...tery-P853.aspx is the way to go. I don't know what your saber design is like, so picking out battery solutions is a bit tricky.

    There are many, many options when building a saber. You typically have to make some compromises at some point. You can go for the brightest, or the loudest, or the longest running, but you're not gonna get the best of everything without building an ENORMOUS saber.
    We all have to start somewhere. The journey is all the more impressive by our humble beginnings.

    http://led.linear1.org/1led.wiz for the lazy man's resistor calculator!
    http://forums.thecustomsabershop.com...e-to-Ohm-s-Law for getting resistor values the right way!

  7. #7

    Default

    Thats what i figured. Thanks for the replies, its been VERY helpful!

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
  •