Results 1 to 3 of 3

Thread: Maths/Resistor Query/check when using Nano Biscotte V3

  1. #1

    Default Maths/Resistor Query/check when using Nano Biscotte V3

    Using a:
    Nano Biscotte v3
    Seoul P4 blue LED 3.5W
    18650 Li-po cell 3.7v 3000mah
    AV switch (led requirements= 3.3v 20mA)

    Using that cell and the biscotte my resister needed for the led is
    R=(Vsupply-Vled)/ Led currant
    R=(3.7-3.5)/1A=0.2ohm
    Looking on bicottes manual they recommend using the Drive adjustments for anything less than 0.5ohm

    So calculating the drive value:
    Drive= 1023x(3.5/3.7)= 967.7 <----should i round up or down for this?

    Lastly the Power indicator resistor (for the Lit AV switch)
    R= (Vsupply-Vled) / LedCurrent
    So inputting my maths

    (3.3v-3.3v)/.02=0?

    So no resistor required for both the main Led and the Switch Led?
    I cant seem to find anyone else with this kind of setup
    Thanks for the help in advance

    Edit: Even if i used a fully charged Li-po at a rounded value of 4.2v And took the Max forward voltage of the Seoul P4 (4v) I still have the same issue of a required resistor of 0.2ohm
    Last edited by thetopcat; 04-22-2017 at 05:02 PM.

  2. #2

    Default

    Math is valid.

    Many would recommend using a 0.1ohm resistor to protect your LED in any case, but you can eschew the resistor. A resistor is cheap and relatively small compared to the work and cost of repairing your saber if the LED burns out.

  3. #3

    Default

    Thanks jbkuma
    If i get a 0.1ohm resistor should i still do the Drive value on the Nano?

Tags for this Thread

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
  •