Overclock.net › Forums › Case Mods & Cases › Builds & Case Mods › Case Mods › LED Question
New Posts  All Forums:Forum Nav:

LED Question

post #1 of 8
Thread Starter 
I feel dumber just asking this question but I was standing in radio shack and had a complete brain fart. I went to pick up some 5mm LED's to moun in the back of a XSPC rasa res. and there were two types one was 5v and one was 3.7v the 3.7 was brighter (considerably) and I could not for the life of me remember how to pull the voltage down from the 12v power feeds to what I need for the LED's
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
post #2 of 8
Here you go: http://led.linear1.org/1led.wiz
post #3 of 8
Thread Starter 
That is freaking awesome, thanks man
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
post #4 of 8
Thread Starter 
So whats the rule if I put 2 inline? Make sure the total resistance is = 470 (thats what the converter gave me)

EDIT: saw the option to choose more than 1
Edited by PLeXuS4200 - 5/16/11 at 6:12pm
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
Paper Weight
(11 items)
 
Home Work
(15 items)
 
 
CPUMotherboardGraphicsRAM
i7 2600k  Gigabyte Z68 UD6H-B3 GTX 580 HC2 2x4 GB G.Skill Ripjaw X 2133 
Hard DriveCoolingOSMonitor
A-Data N001 SSD  XSPC Rasa 750 Win 7 Ult. 64bit Asus 22" 
PowerCaseAudio
Corsiar TX750 Antec 1200 X-Fi Xtreme Gamer 
CPUMotherboardGraphicsRAM
Q6600 (3.6Ghz 1.487v) Asus P5Q-E (2x CF)Sapphire HD 4870 512 & 1GB 4GB (2x2GB) G.Skill PC8000 
Hard DriveOptical DriveCoolingOS
A-Data N002 128GB SSD, 1.5TB WD Green Pioneer DL-DvD/RW XSPC RASA 360 push/pull Windows 7 64bit Ultimate 
MonitorKeyboardPowerCase
22" Asus WS-HD VK222H Logitech Elite Corsair Tx750 Antec 1200 
MouseMouse PadAudio
Logitech G5 Series 2 Rocketfish 2 sided X-Fi Xtreme Gamer / Logitech 5.1 
  hide details  
Reply
post #5 of 8
i did the same thing a few weeks ago. i went to The Source (Canada's Radio Shack) and looked at the LEDs they had. they wanted like $5 for 2 5mm Red LEDs. So i went on Ebay and ordered 100 Red LEDs with 100pcs 100Ohm resistors for less than $9 shipped from Hong Kong. It took 9 days to arrive.

With the 100Ohm resistors i could use 5 LEDs in series on 12v. i have 30 total in my case right now. They are not the brightest but for the price they are great!
HAL 9000
(13 items)
 
  
CPUMotherboardGraphicsRAM
Phenom II X6 1055T Asus M4A89GTD PRO/USB3 XFX/Sapph HD5770 Crossfire 8GB 
Hard DriveMonitorPowerCase
Crucial C300 64GB, WD Black 1TB 22" + 23" Ultra 750W Cool Master HAF 922 
  hide details  
Reply
HAL 9000
(13 items)
 
  
CPUMotherboardGraphicsRAM
Phenom II X6 1055T Asus M4A89GTD PRO/USB3 XFX/Sapph HD5770 Crossfire 8GB 
Hard DriveMonitorPowerCase
Crucial C300 64GB, WD Black 1TB 22" + 23" Ultra 750W Cool Master HAF 922 
  hide details  
Reply
post #6 of 8
Or....and it seems like everyone forgets this... use the 5V to power them, not the 12V circuit...voila, no resistors. Or, the 3.3V circuit too.
My System
(13 items)
 
  
CPUMotherboardGraphicsRAM
5000+ BE 3.4G @1.447v DFI 790FX-M2RS Sapphire 3850 8G Corsair XMS2 DHX 
Hard DriveOSPower
Seagate Win7 Ultimate 64bit Antec TPQ-850 
  hide details  
Reply
My System
(13 items)
 
  
CPUMotherboardGraphicsRAM
5000+ BE 3.4G @1.447v DFI 790FX-M2RS Sapphire 3850 8G Corsair XMS2 DHX 
Hard DriveOSPower
Seagate Win7 Ultimate 64bit Antec TPQ-850 
  hide details  
Reply
post #7 of 8
Just remember
- Ohm's Law for the voltage drop across a resistor - V=IR
- Power law for the power consumed by an element - P=VI : P=(I^2)*R for a resistor
- Voltages/resistances add in series
- currents add in parallel
RAD GT
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i5 2500K MSI P67A-GD65 eVga GeForce GTX 480 Hydro Copper G.Skill Ripjaws X DDR3-1066 4x4Gb 
Hard DriveOptical DriveCoolingOS
2x 500Gb SATA | 750Gb SATA | 1Tb SATA LG SATA DVD-RW DangerDen Water Windows 7 Ultimate X64 
MonitorMonitorPower
AOC 2236VW 1920x1080 22" WS AOC 2236VW 1920x1080 22" WS SilverStone Strider ST850 
  hide details  
Reply
RAD GT
(15 items)
 
  
CPUMotherboardGraphicsRAM
Intel Core i5 2500K MSI P67A-GD65 eVga GeForce GTX 480 Hydro Copper G.Skill Ripjaws X DDR3-1066 4x4Gb 
Hard DriveOptical DriveCoolingOS
2x 500Gb SATA | 750Gb SATA | 1Tb SATA LG SATA DVD-RW DangerDen Water Windows 7 Ultimate X64 
MonitorMonitorPower
AOC 2236VW 1920x1080 22" WS AOC 2236VW 1920x1080 22" WS SilverStone Strider ST850 
  hide details  
Reply
post #8 of 8
Quote:
Originally Posted by Furball Zen View Post
Or....and it seems like everyone forgets this... use the 5V to power them, not the 12V circuit...voila, no resistors. Or, the 3.3V circuit too.
Unless you have LED with built in resistors you need to limit the current around 20mA will be the probably be the max. The resistor needed will vary quite a bit with supply voltage. i.e you might want 150Ω or 500Ω depending on 5V or 12V. I am approximating the forward voltage at 2V, I did solid state physics 20 year ago and can't remember excatly what it is. get it wrong and you might find it dim or you cooked yer LED.
To work it out it will be something like:

resistor_needed:=(supply_voltage-forward_voltage) / diode_current.


As an alerntaive to cheap LEDs you can get really bright LED's. I mounted some in the face of a bike speedo, I put all the idiot lights on the speedo face, I got something like a superhyper[?] bright red LED for the oil light and at whatever was the mid current recomended it was blinding! it looked more like a laser, you could see it with your eyes closed!
Edited by integerspin - 5/23/11 at 3:03pm
bigbox
(13 items)
 
  
CPUMotherboardGraphicsRAM
Opteron146 MSi? Quadro FX3500 1 G PC2700 
Hard DriveOptical DriveMonitorPower
320G WD, 10 assorted scsi drives 2 plextor CD drives and a Sony CD drive Compac 21" and a Hanns 19" cheap thing with a blue LED in it 
Case
Dec prioris HX server case 
  hide details  
Reply
bigbox
(13 items)
 
  
CPUMotherboardGraphicsRAM
Opteron146 MSi? Quadro FX3500 1 G PC2700 
Hard DriveOptical DriveMonitorPower
320G WD, 10 assorted scsi drives 2 plextor CD drives and a Sony CD drive Compac 21" and a Hanns 19" cheap thing with a blue LED in it 
Case
Dec prioris HX server case 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Case Mods
Overclock.net › Forums › Case Mods & Cases › Builds & Case Mods › Case Mods › LED Question