1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Don't know what Resistor to use

Discussion in 'Xbox - Hardware mods' started by Guarino, Mar 14, 2011.

  1. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    Im am placing some 5mm UV LED's in my 360.

    I have ordered the LED's already but dont know how to find out what resistor I should use,100, 180, 220 ohm, just have no idea, and I have tried figuring out the calculator for this but not really understanding much of it.

    So I was wounding if someone could please help me out
    I am wanting to use 8-10 LED's

    Here are the spec's on the LED's.

    http://alan-parekh.vstore.ca/uv-led-5mm-3000mcd-p-16.html

    LED Specifications

    Emitted Colour : UV (ULTRA VIOLET)
    Size (mm) : 5mm T1 3/4
    Lens Colour : Water Clear
    Peak Wave Length (nm) : 380 ~ 400
    Forward Voltage (V) : 3.2 ~ 3.6
    Typical Voltage (V) : 3.4
    Reverse Current (uA) : <=30
    Luminous Intensity Typ Iv (mcd) : 2000 ~ 3000(Max)
    Life Rating : 80,000 ~ 100,000 Hours
    Viewing Angle : ±10°
    Absolute Maximum Ratings (Ta=25°C)
    Max Power Dissipation : 80mw
    Max Continuous Forward Current : 30mA
    Max Peak Forward Current : 75mA
    Reverse Voltage : 5~6V
    Lead Soldering Temperature : 240°C (<5Sec)
    Operating Temperature Range : -25°C ~ +85°C Preservative Temperature Range : -30°C ~ +100°C
     
    Last edited: Mar 14, 2011
  2. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    *BUMP*

    Anyone?
     
  3. TreePro

    TreePro Regular member

    Joined:
    Mar 1, 2010
    Messages:
    145
    Likes Received:
    0
    Trophy Points:
    26
    Assuming you will use the 12 volts of power the LED you selected according to the sites calculator you will need a 330 ohm .5 watt per LED. Or up to max of 3 in series a single 68 ohm .25 watt resistor in series with LED's. To put 8 in series you would need min 28 volts so max of 3 in series at 12 volts.
     
  4. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    So how are you saying I should wire this up? From my understanding my options would be : One resistor per set of 3 LEDs will use one 68 ohm .25 w? (or) 8 LEDs with one 330 ohm .5 w?
     
  5. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    okay how about this, what resistor should I use if I wanted to use 8 LED's and have one resistor per LED?

    Sorry, I love doing this kind of thing but when I go to the calculator I just dont understand how it works..
     
  6. TreePro

    TreePro Regular member

    Joined:
    Mar 1, 2010
    Messages:
    145
    Likes Received:
    0
    Trophy Points:
    26
    330 ohm .5 watt per LED if you use a 12 volt input.
     
  7. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    So much appreciated!!
     
  8. TreePro

    TreePro Regular member

    Joined:
    Mar 1, 2010
    Messages:
    145
    Likes Received:
    0
    Trophy Points:
    26
    No problem, glad to help. Remember to observe the polarity on LED, positive to Anode or it won't work.
     
  9. Guarino

    Guarino Member

    Joined:
    Mar 9, 2011
    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    11
    What do you mean exactly?
     
  10. TreePro

    TreePro Regular member

    Joined:
    Mar 1, 2010
    Messages:
    145
    Likes Received:
    0
    Trophy Points:
    26
    Diodes will only allow current to flow in one direction So, you must connect them properly. A LED is a Light Emitting Diode. The longest lead is the Anode so positive is connected here. There is a flat spot also on most led's which is Cathode (shorter lead) and the negative is connected here. All LED's have a maximum continuous current, if exceeded they will burn out so, that is why resistor is needed to limit current. Different voltage require different resistor for same type LED.
     

Share This Page