Custom tail LED brightness

[wildweasel_pt]

Hi all

I want to make a custom tail light and blinkers for my bike and i've been browsing the web trying to find out the proper brightness for the LEDs. I was thinking of getting the brightest and if too much i'd just use resistors to dim it. Any way if anyone can let me know what would be a good number in mCd for this use i'd be appreciated. I want to use standard clear 8mm LEDs not the straw hat type LEDs. Im also thinking of using the same LEDs for running and braking lights so a parallel circuit with a resistor for running and straight circuit for braking light might be the best option but i'd also like to know what you all have to say regarding alternatives. So all i need to know is:

Clear bulb Amber 8mm LEDs - ???mCd
Clear Bulb Red 8mm LEDs - ???mCd (Used for running and braking)

Thanks in advance...

 

[Diablotin]

I would check what Radianz is offering. They may even give detailed specifications.

With that you might get a baseline.

Sent from my GT-I9100 using Tapatalk 2

 

[wildweasel_pt]

And do you think they'll give me the specs on the LEDs? Hmm don't see that happening though...

 

[timscues]

Sean offers a real nice taillight

 

[satariel666]

Besides luminous intensity defined in Candels diodes also have luminous angle.
Usualy from around 20 to 180 degrees. For indicators I would use as wide I can but for stop light you might consider max 60'.

20 000 mC is a max luminous intensity what you will get from electronic shops(if we are talking about 5mm leds which are commonly used)and use as much intensity as you can archive as leds have much lower parameters as bulbs anyway.

Usualy super bright 5mm(never used 8mm) led consumes 20mA with 3,2 V of suply voltage.
For calculating proper balast resistors use one of hundreds free online LED calculators
if I=U/R is to complicated for you. You may also consider using for diodes in series, one resistor and suply directly from 12V. I've seen also some 12v leds on market.


Datasheets for diodes were alsways avaible...free. Just ask the seller what manufacter they are reseeling.

 

[wildweasel_pt]

I know everything i need besides the optimal brightness. Thats all i want to know. I've seen LEDs going from 5KmCd to 200KmCd (straw hat type with multiple chips) so i was a little confused on what to use because price varies a lot. Thank you for the thorough explanation though.
Usually brighter LEDs have narrower beams as well... I think i'll be set with 45KmCd ones that i found to be cheap enough...
I will be doing several series of 6 LEDs (for rated 2v) or 4 (rated 3v) in parallel. That will make it in order not to need extra resistors and increase consumption. Im considering using the same LEDs for running and braking lights and for that i'll be needing a resistor on the running light circuit to decrease current and thus reducing brightness. I thought someone would have an idea on what resistor rate to use... I'll need to calculate that afterall after i define how many series i'll have on the circuit.

 

[wildweasel_pt]

Sean offers a real nice taillight

I bet he doesn't have what im looking for... :biglaugh:

 

[satariel666]

I know everything i need besides the optimal brightness. Thats all i want to know. I've seen LEDs going from 5KmCd to 200KmCd (straw hat type with multiple chips) so i was a little confused on what to use because price varies a lot. Thank you for the thorough explanation though.
Usually brighter LEDs have narrower beams as well... I think i'll be set with 45KmCd ones that i found to be cheap enough...
I will be doing several series of 6 LEDs (for rated 2v) or 4 (rated 3v) in parallel. That will make it in order not to need extra resistors and increase consumption. Im considering using the same LEDs for running and braking lights and for that i'll be needing a resistor on the running light circuit to decrease current and thus reducing brightness. I thought someone would have an idea on what resistor rate to use... I'll need to calculate that afterall after i define how many series i'll have on the circuit.

5mm 20Cd is what is comonnly used in tailights, more for indicators maybe around 30Cd.

Google a "led calculator" and you will get a lot of results...like this:
http://www.hebeiltd.com.cn/?p=zz.led.resistor.calculator

 

[wildweasel_pt]

Thanks...

 

[bazwell]

Hey Fred, I'm just finishing up making led lights. Do you still need this info?
PM me.