madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: billstein on April 24, 2015, 06:12:03 AM

Title: Resistor Values for LED's
Post by: billstein on April 24, 2015, 06:12:03 AM
Hi all. Just a quick question. What resistor values do you use for Led's.
1. For diffused?
2. For waterclear?

Thank you
Title: Re: Resistor Values for LED's
Post by: cooder on April 24, 2015, 07:54:56 AM
I use 10K for water clear high brightness LEDs. Works good for me.
Title: Re: Resistor Values for LED's
Post by: alanp on April 24, 2015, 08:24:52 AM
For 9V? 4K7 for normal.

Swearing for different.
Title: Re: Resistor Values for LED's
Post by: cooder on April 24, 2015, 09:00:15 AM
Quote from: alanp on April 24, 2015, 08:24:52 AM
For 9V? 4K7 for normal.

Swearing for different.
Well 10 K is  a little less bright than 4k7 but still enough to light up my music room when my board is powered up.... just not too retina scorching.
Title: Re: Resistor Values for LED's
Post by: Mich P on April 24, 2015, 12:21:37 PM
Diffused      :     1 to 4.7K
Waterclear  :  15 to 100K
Mich P.
Title: Re: Resistor Values for LED's
Post by: HKimball on April 24, 2015, 12:51:30 PM
Wow that explains a lot - I just use 4.7k for everything haha. Makes sense now why my white LEDs on my 18v pedals are like staring into the sun
Title: Re: Resistor Values for LED's
Post by: muddyfox on April 24, 2015, 02:55:37 PM
yeah I'm with Mich. All over the place, depending on the application.
Title: Re: Resistor Values for LED's
Post by: jimilee on April 24, 2015, 03:17:29 PM

Quote from: cooder on April 24, 2015, 07:54:56 AM
I use 10K for water clear high brightness LEDs. Works good for me.
Great to know! I've never even thought about it, just complained to myself.


Sent from my iPhone using Tapatalk
Title: Re: Resistor Values for LED's
Post by: davent on April 24, 2015, 03:52:27 PM
I have a lot of random LED's (sorted by colour) from many different suppliers, diffused/clear, three sizes etc., i check each one before installing to get the appropriate clr and that has ranged from ~500r to 47k. Have a box with 24 steps  from 500r to 18k to test for a clr value.

(http://i216.photobucket.com/albums/cc305/davent/IMG_4619.jpg)
(http://i216.photobucket.com/albums/cc305/davent/IMG_4614.jpg)
Title: Re: Resistor Values for LED's
Post by: billstein on April 24, 2015, 04:12:35 PM

Quote from: davent on April 24, 2015, 03:52:27 PM
I have a lot of random LED's (sorted by colour) from many different suppliers, diffused/clear, three sizes etc., i check each one before installing to get the appropriate clr and that has ranged from ~500r to 47k. Have a box with 24 steps  from 500r to 18k to test for a clr value.

(http://i216.photobucket.com/albums/cc305/davent/IMG_4619.jpg)
(http://i216.photobucket.com/albums/cc305/davent/IMG_4614.jpg)

That's a great idea.
Is that resistor on the left a safeguard so you don't apply to much voltage and burn out the LED?
Is that a 1x12 rotary switch?
Title: Re: Resistor Values for LED's
Post by: pickdropper on April 24, 2015, 04:28:05 PM
Usually between 1k and 5k for diffused and between 15k and 20k for ultraclear.
Title: Re: Resistor Values for LED's
Post by: davent on April 24, 2015, 04:45:24 PM
Quote from: billstein on April 24, 2015, 04:12:35 PM

Quote from: davent on April 24, 2015, 03:52:27 PM
I have a lot of random LED's (sorted by colour) from many different suppliers, diffused/clear, three sizes etc., i check each one before installing to get the appropriate clr and that has ranged from ~500r to 47k. Have a box with 24 steps  from 500r to 18k to test for a clr value.

...

That's a great idea.
Is that resistor on the left a safeguard so you don't apply to much voltage and burn out the LED?
Is that a 1x12 rotary switch?

That's just a 10k that gets added in series with other 12 resisitors  so you get the next 12 higher steps.

Have an amp with  a bicolour led that needed a quite different clr for each colour to achieve equal levels of brightness, there is no one size fits all.
Title: Re: Resistor Values for LED's
Post by: billstein on April 24, 2015, 11:46:48 PM
Thanks guys.

I always use 4k7 for diffused but tried a waterclear blue with 4k7 and now I think I need to replace the retina in my eye! :)
So, just wanted to know if there was a consensus out there for the high brightness LED's. I'm hearing anywhere from 10K all the way to 100K.
I might have to build a tester like davent.
Title: Re: Resistor Values for LED's
Post by: guile on April 25, 2015, 11:58:10 AM
Quote from: billstein on April 24, 2015, 04:12:35 PM

Quote from: davent on April 24, 2015, 03:52:27 PM
I have a lot of random LED's (sorted by colour) from many different suppliers, diffused/clear, three sizes etc., i check each one before installing to get the appropriate clr and that has ranged from ~500r to 47k. Have a box with 24 steps  from 500r to 18k to test for a clr value.

(http://i216.photobucket.com/albums/cc305/davent/IMG_4619.jpg)
(http://i216.photobucket.com/albums/cc305/davent/IMG_4614.jpg)

That's a great idea.
Is that resistor on the left a safeguard so you don't apply to much voltage and burn out the LED?
Is that a 1x12 rotary switch?

Completely OT: wheredid you find that LED-tester? Would love to have one
Title: Re: Resistor Values for LED's
Post by: davent on April 25, 2015, 05:17:17 PM
Just a bunch of random bits gathering dust thrown together into something useful. Idea was put forward by Mark Hammer over at diysb.
dave
Title: Re: Resistor Values for LED's
Post by: peAk on April 25, 2015, 06:25:47 PM
Very cool Dave!
Title: Re: Resistor Values for LED's
Post by: guile on April 25, 2015, 06:38:33 PM
Quote from: davent on April 25, 2015, 05:17:17 PM
Just a bunch of random bits gathering dust thrown together into something useful. Idea was put forward by Mark Hammer over at diysb.
dave

Well... Could you throw that together again? ::)
Title: Re: Resistor Values for LED's
Post by: muddyfox on April 26, 2015, 06:49:14 AM
i do it on a small breadboard. A led, followed by a 1k followed by a 100kB pot. insert led, twist pot till desired led brightness, measure pot, add 1k :)
i have a tiny breadboad dedicated to this, with two pots so that i can judge the brightness of two separate leds at the same time (because sometimes even leds from the same batch are sufficiently different in output). not fancy but very efficient and easy to put together and use.