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how to light up a led!??

k!, i just bought a new led at radioshack
a bi-color led well, the problem is that
i don't know how to light it up!!
any one got ideas!??


the specs on the back of the led!

power dissipation 100mW
Continuous Forward current 30mA
Reverse current: 10A(0.05V)
Forward Voltage: 2.8V
Reverse Voltage: 5V

Foward Voltage: 20V (red)
2.1V (green)
2.5mcd
Lumens Intensity 54
Peak Emission 635nm (red)
Wavelength: 565nm (green)

Comments

  • HylsanHylsan Posts: 11Member
    if im not mistaking, the led comes with three "pins".
    one anod and two katods (or the otherway around, always mix 'em up).
    so...simply put 20v on one and 2.1v on the other (tho that 20v sounds wrong...dunno how to check wich one is the red or green pin...should say in the datasheet tho...
    and dont forget those resistors :)

    /Hylsan

    : k!, i just bought a new led at radioshack
    : a bi-color led well, the problem is that
    : i don't know how to light it up!!
    : any one got ideas!??
    :
    :
    : the specs on the back of the led!
    :
    : power dissipation 100mW
    : Continuous Forward current 30mA
    : Reverse current: 10A(0.05V)
    : Forward Voltage: 2.8V
    : Reverse Voltage: 5V
    :
    : Foward Voltage: 20V (red)
    : 2.1V (green)
    : 2.5mcd
    : Lumens Intensity 54
    : Peak Emission 635nm (red)
    : Wavelength: 565nm (green)
    :

  • FreakboYFreakboY Posts: 117Member
    nope, it only has 2 pins!!!
    anymore ideas!??


    thanx!
  • ItmusItmus Posts: 1Member
    : k!, i just bought a new led at radioshack
    : a bi-color led well, the problem is that
    : i don't know how to light it up!!
    : any one got ideas!??
    :

    You will have to use a DC source of 12V (or any other but the circuit will change if you use another voltage), a resistance and the led.

    The circuit will look like this:

    12V (+) ---- Resistance ---- (+, anode) Led (-, cathode) ---- 12V (-)

    The anode of the led is the longuest pin. The led will have a maximum brightness if you have a current of 30mA in it. To do so, choose a resistance of approximatly 310 ohms ( (12V - 2.8V) / 30mA ). Do not choose a resistance value smaler than 310 ohms because you will burn your led. If you want to use less current (but less brightness), use a resistance bigger than 310 ohms.

    You should be ok with this!

    Itmus

  • ryo_samaryo_sama Posts: 18Member
    Hie.
    I think the diods are conected like this.
    |---->|----|
    ---| |----
    |----|<----|
    mening that if you aply voltage one way its red and the other way its green. As for a smart way of conecting it i think it can be done with 2 transistors that pull up one side of the diod and one resistor 2 ground.


    : k!, i just bought a new led at radioshack
    : a bi-color led well, the problem is that
    : i don't know how to light it up!!
    : any one got ideas!??
    :
    :
    : the specs on the back of the led!
    :
    : power dissipation 100mW
    : Continuous Forward current 30mA
    : Reverse current: 10A(0.05V)
    : Forward Voltage: 2.8V
    : Reverse Voltage: 5V
    :
    : Foward Voltage: 20V (red)
    : 2.1V (green)
    : 2.5mcd
    : Lumens Intensity 54
    : Peak Emission 635nm (red)
    : Wavelength: 565nm (green)
    :

  • cfhcfh Posts: 5Member
    : nope, it only has 2 pins!!!
    : anymore ideas!??
    :
    :
    : thanx!
    :
    Yeah, what you have is a bidirectional LED. when you send current through it one way it lights red, when you send it through the other way it lights greedn!.. OR. if you run AC through it it'll light up BOTH colors.

    in either case the resistor is about the same,, I saw a misprint, it will be about 2.0 volts forward either direction.
    so figure the resistor this way for an input of V volts:

    v(v-2)/.02 = resistor in ohms

    (v-2) X .02 = resistor wattage in watts. ( it has to be at LEAST this large

    Let's say you want to run it on 6V, 6-2=4 4/.02= 200 ohms
    4* .02 + .08 so wee need at least a 1/12 watt resistor
    ( ok they don't make them THAT small, so anything over 1/10 watt will do fine!)

    c

  • ericj2190ericj2190 Posts: 11Member
    Apply 3 volts to one side and GROUND to center or vice versa if the first fails.
    -EricJ2190


  • ericj2190ericj2190 Posts: 11Member
    20v proply should be 2.0v

    : if im not mistaking, the led comes with three "pins".
    : one anod and two katods (or the otherway around, always mix 'em up).
    : so...simply put 20v on one and 2.1v on the other (tho that 20v sounds wrong...dunno how to check wich one is the red or green pin...should say in the datasheet tho...
    : and dont forget those resistors :)
    :
    : /Hylsan
    -EricJ2190


  • ericj2190ericj2190 Posts: 11Member
    apply 3v to one and GND to the other.

    -EricJ2190


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