Run Red LEDs on same circuit?

Matty1973 · Post by **Matty1973** » Sat Apr 23, 2011 4:24 pm

Ok so I have a circuit that has 20 white LEDs that runs on 9v DC, a 15 ohm 5watt resistor, works great but I want to add 2 red LEDs to it, can this be done if each red LED has it's own resistor on the positive lead? If yes will a 300ohm resistor be the choice?[/quote]

robiwon · Post by **robiwon** » Sat Apr 23, 2011 6:57 pm

Input the specs for your red LEDs here and your source voltage. It will tell you what resistor to use.

http://led.linear1.org/led.wiz

Matty1973 · Post by **Matty1973** » Sat Apr 23, 2011 7:10 pm

robiwon wrote:Input the specs for your red LEDs here and your source voltage. It will tell you what resistor to use.

http://led.linear1.org/led.wiz

I am not sure it really helps me as the setup i want requires 22 3-3.4v white LEDs and 2 Red LEDs at 1.8v, and i cant enter in that info

USS Atlantis · Post by **USS Atlantis** » Sat Apr 23, 2011 7:23 pm

Matty1973 wrote:
robiwon wrote:Input the specs for your red LEDs here and your source voltage. It will tell you what resistor to use.

http://led.linear1.org/led.wiz
I am not sure it really helps me as the setup i want requires 22 3-3.4v white LEDs and 2 Red LEDs at 1.8v, and i cant enter in that info

Enter it as if each were a different circuit - that's actually what you're doing

You can run multiple circuits from one power source, take each "group" of LED's separately

When doing parallel runs of LED's from a single power source, each is electrically a separate circuit, even though they share the battery/wall-wort/etc

robiwon · Post by **robiwon** » Sun Apr 24, 2011 8:33 am

Exactly. The other LEDs dont matter at this point. What you want is to know what resistor to use for your red LEDs and a 9v power source. The white ones wont effect the answer to that question.

Matty1973 · Post by **Matty1973** » Sun Apr 24, 2011 8:40 am

Thanks all, I understand now, it's all under control

paraclete1 · Post by **paraclete1** » Sun Apr 24, 2011 2:29 pm

Matty1973 wrote:Thanks all, I understand now, it's all under control

I like all the lighting and detail. Did the kit come with the open shuttlebay? And do you remember what LEDs you used for the blinking lights? Were they self blinking or did you have an IC set up?

Matty1973 · Post by **Matty1973** » Sun Apr 24, 2011 7:10 pm

paraclete1 wrote: I like all the lighting and detail. Did the kit come with the open shuttlebay? And do you remember what LEDs you used for the blinking lights? Were they self blinking or did you have an IC set up?

The blinking lights are run by the trek modeler kit, which includes all the blinkers and strobes, and for the shuttlebay I just left the doors off

paraclete1 · Post by **paraclete1** » Sun Apr 24, 2011 9:03 pm

Matty1973 wrote:
paraclete1 wrote: I like all the lighting and detail. Did the kit come with the open shuttlebay? And do you remember what LEDs you used for the blinking lights? Were they self blinking or did you have an IC set up?
The blinking lights are run by the trek modeler kit, which includes all the blinkers and strobes, and for the shuttlebay I just left the doors off

Thanks. Great Work.