How to make your own LED lightbulbs

Step 5

The aluminium sheet will serve as a light reflector and a holder for LEDs in the same time so take care not to bend it. After cutting out the holes its time to see how the led's should be connected.

Go to http://led.linear1.org/led.wiz and fill in the fields with your parameters. Here's a screenshot of what the wizard reccomended for my 22 LEDs 12V array. So now I know how to connect them.

Comments

[bas98]

Why do you need the 1 ohm resistor??

[panchavanparivendhan]

so that the led wo'nt burn

[asafche]

See this. it will explain way - http://led.linear1.org/why-do-i-need-a-resistor-with-an-led/

[claudiopolis]

Just to be on the safe side. The LED calculator reccomended it so I used it. It protects the LED from overdriving by reducing the voltage a bit. You might skip it but you'd better be sure of the voltage applied.

[siamonsez]

I bought a packet of leds that came with 200 ohm resistors. The calculator says to use 1 82ohm resistor per led which is 3-3.2v @ 20mA with a 4.5v power source. After playing with the calculator a bit a can't find any instance which asks for 200ohm resistors, but using wolfram alpha to calculate 4.5v with 200 ohms of resistance, it says 22.5 mA which is near enough the proper current for the leds.
I don't know if i'm misunderstanding something but it seems to me that these are at odds, any help would be great.
Are the 200 ohm resistors meant to be used with a higher voltage? I'm assuming a 1x array because the pack came with the same amount of leds and resistors, is that wrong? can someone explain what will happen if I wire:
(4.5v) > (3vLED) > (200ohm resistor).

[hubi]

Very nice, but it is only for DC.
If yo wire the LED chains in atiparallel, like in that instructable, you can use it at 12V AC, but it wil flicker a bit.

[11010010110]

antiparallel is made to reduce flicker you can place bridge and filtering capacitor inside to eliminate flicker almost completely you can use 4 of the leds as the bridge diodes (bridge of its own for each series line) and no capacitor. the 4 leds that form the bridge will be dim and flicker and all the rest will be 2X brighter and flicker at 100 HZ which is invisible

[Kryptonite]

Damn I hate being only knowledge upon the arts of Dc.