LED Wiring Help

[cklinh]

So I bought these on eBay...

Pre-wired LED's

they're LED's prewired with a resistor...

I'm hooking 5 or 6 of them up together for car use... for all you smarties out there, should I wire them up in series or in parallel?

I thought series would work, but when I tested them out, it seemed to be dimmer... wiring in parallel seems to make everything as bright as possible, but there is a drawback right? (heat, maybe?)

Circuits wasn't always my best subject, and I'd hate to have to bust out the books

[Sentinel]

When you wire stuff up in series each item gets a fraction of the voltage (it's divided evenly if the resistances are the same) whereas stuff in parallel all see the same (full) voltage. Thats why they're brighter in parallel.

If you have enough LEDs in series you shouldn;t need the resistor. Do you have a meter to find their resistance?

You really need to know the voltage rating of an individual LED. That will determine the best way to wire them. You may end up with a combination series-parallel circuit.

I take it the mfg. is not helpful?

[cklinh]

Haven't talked to them yet... but since they were marketing the LED/resistors as for car use, I'd imagine they were designed for 12 V.

Then, wiring in parallel will allow me to use them all together without removing the resistor. But is there a drawback to wiring them in parallel?

LED Info:
# Wavelength: 620nm-630nm
# Luminous Intensity-MCD: Min:40000cd Max: 60000 mcd
# Reverse Voltage:5.0 V
# DC Forward Voltage: Typical: 12.0 V Max: 15.0V
# DC Forward Current:20mA

[Sebas007]

Are you planning to do the 3rd brake light with LED as Milton did ?? If so I'm interested in DIY ! I quickly check how can access the interior of the 3rd brake light...I didn't find.

[cklinh]

If I get it to work, I'll have a tutorial.

I've gotten the rear deck off before while replacing the speakers, and it didn't look like that much of a problem to remove the lens/reflector on the brake light. I was planning on having something that plugs into the 194 bulb socket... just gotta figure out wiring

[cklinh]

Response from seller is to wire them in parallel.

[Sebas007]

Nice stuff !

By the way, thanks for your hint on the flasher resistor unit !! Gone in 60 seconds !!