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geekhack Community => Keyboards => Topic started by: tbc on Mon, 28 April 2014, 23:37:39

Title: Please help me with my LED shopping list :D
Post by: tbc on Mon, 28 April 2014, 23:37:39
I'm working on getting parts for a GON board that is going to get blinged out on LEDs...but I'm trying things out on a techkeys business card first. 

basically, I want my switch LEDs to send out as much light as possible.  To that end, I'm planning on clear mx tops + sip sockets + the most diffused LEDs.

I just want to know if I'm getting the best LEDs + compatible sip sockets at a reasonable price.  My planned order is:

http://www.ebay.com/itm/50pcs-8Pin-DIP-SIP-Round-IC-Sockets-Adaptor-Solder-Type-gold-plated-machined-/300932442547?pt=LH_DefaultDomain_0&hash=item4610f8a9b3
http://www.ebay.com/itm/100pcs-2x3x4mm-Rectangle-Blue-Water-Clear-LED-Light-Leds-/320999090146?pt=LH_DefaultDomain_0&hash=item4abd0967e2
http://www.ebay.com/itm/100pcs-2x3x4mm-Rectangle-Orange-Water-Clear-LED-Light-Leds-/320999088871?pt=LH_DefaultDomain_0&hash=item4abd0962e7
http://www.ebay.com/itm/100pcs-2x3x4mm-Rectangle-Red-Water-Clear-LED-Light-Leds-/221138055543?pt=LH_DefaultDomain_0&hash=item337cdaf177


should I expect a high failure rate and double up on LEDs? I plan on using these for a single 75% board.  I'm buying multiple colors to change based on tastes and to match specific backlit caps; but each color needs to be able to cover the whole board.

how are sip sockets counted?  50 means thats enough for 25 switches?  or does it mean 50 pairs of sip sockets?

also, how do I know what resistors to buy? would I need to replace resistors on the techkeys card (i actually don't see any....)?
Title: Re: Please help me with my LED shopping list :D
Post by: n0rvig on Tue, 29 April 2014, 00:11:43
For the SIP sockets, those might be okay. I picked up a bunch all in a row. It seems easier to take them apart that way.

http://www.ebay.com/itm/5-x-40-Pin-DIP-SIP-IC-Sockets-Adaptor-Solder-Type-USA-SELLER-Free-Shipping-/321385380547

Sorry, someone else can tell you about the LEDs
Title: Re: Please help me with my LED shopping list :D
Post by: tbc on Tue, 29 April 2014, 00:55:27
thanks for the link.  they're saying they don't ship to canada though :/
Title: Re: Please help me with my LED shopping list :D
Post by: Oobly on Tue, 29 April 2014, 04:32:03
You need 2 SIP pins for each LED.

You can use this to calculate the resistor values if you know the specs of the LED's: http://ledcalc.com/

The rectangular LED's like you have listed disperse the light well under the caps, the round ones tend to focus it right above them. Most reputable LED sellers will know the output power of the LED's they sell. The more Lumens (lm) or milliCandelas (mcd) the brighter. I have no idea how bright the ones you listed are or what their current ratings are.

Something to be careful of is the current supplied by USB. If you use super bright LED's and supply close to their max current rating you will most likely exceed the current rating of some USB ports and particularly USB hubs. USB 1.0 has a max current limit of 150mA, USB 2.0 is 500mA, USB 3.0 is 900mA and USB 3.1 is 2A.

Multiply the number of LED's by the calculated current draw for each one to get a figure for the total current that the LED's will use. Keep in mind that the keyboard controller also uses some current, so allow a little for that, too.
Title: Re: Please help me with my LED shopping list :D
Post by: Latin00032 on Tue, 29 April 2014, 05:04:25
I want to do my own leds too.

Good luck.
Title: Re: Please help me with my LED shopping list :D
Post by: Razor Lotus on Tue, 29 April 2014, 08:47:06
You need 2 SIP pins for each LED.

You can use this to calculate the resistor values if you know the specs of the LED's: http://ledcalc.com/

The rectangular LED's like you have listed disperse the light well under the caps, the round ones tend to focus it right above them. Most reputable LED sellers will know the output power of the LED's they sell. The more Lumens (lm) or milliCandelas (mcd) the brighter. I have no idea how bright the ones you listed are or what their current ratings are.

Something to be careful of is the current supplied by USB. If you use super bright LED's and supply close to their max current rating you will most likely exceed the current rating of some USB ports and particularly USB hubs. USB 1.0 has a max current limit of 150mA, USB 2.0 is 500mA, USB 3.0 is 900mA and USB 3.1 is 2A.

Multiply the number of LED's by the calculated current draw for each one to get a figure for the total current that the LED's will use. Keep in mind that the keyboard controller also uses some current, so allow a little for that, too.

Useful information in that post mate :)

I remember someone saying something about having at least 3V for your LEDs or something like that? And most reds don't have enough Vs and you need to add some resistor or something.

Do you have any inputs on that?

Thanks