Super Strip: Difference between revisions
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== Kostyun RGB+W LED Super Strip Flood == | == Kostyun RGB+W LED Super Strip Flood == | ||
* NOTE - THIS PAGE IS A WORK IN-PROGRESS - IT IS NOT COMPLETE YET * | |||
What is the Super Strip Flood? | What is the Super Strip Flood? | ||
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Typically the RGB LEDs are common anode to support typical usage with DCSSRs or other DC controllers that implement switched grounds and common positive voltage. The circuitry has each LED/color with a series current limiting resistor and all LED/resistors are in parallel for each color. While this increases the number of resistors required, it does allow operation with just 5v as well as allowing you to partially populate the strip. The strips are usually run with either 5v or 12v as these are common DC power supply voltages. The use of 5v supplies allows smaller resistors (1/8W) to be used whereas the use of 12v supplies requires larger (1/4W) resistors. | Typically the RGB LEDs are common anode to support typical usage with DCSSRs or other DC controllers that implement switched grounds and common positive voltage. The circuitry has each LED/color with a series current limiting resistor and all LED/resistors are in parallel for each color. While this increases the number of resistors required, it does allow operation with just 5v as well as allowing you to partially populate the strip. The strips are usually run with either 5v or 12v as these are common DC power supply voltages. The use of 5v supplies allows smaller resistors (1/8W) to be used whereas the use of 12v supplies requires larger (1/4W) resistors. | ||
The values of the limiting resistors can be calculated using Ohm's Law: | |||
'''When usng 5vdc:''' | |||
R = V / I or (5v - Vf) / .02 | |||
Assumption is 20mA for the LEDs (this is what they are from the group buy) | |||
Assumption is 2v for Red and 3.1v for Green, Blue and White | |||
Red - (5v - 2v) / .02 = 3v / .02 = 150 ohms | |||
'''150 ohms''' is a common value so the actual current is 3v / 150 = '''20mA''' | |||
Green/Blue/White - (5v - 3.1v) / .02 = 1.9 / .02 = 95 ohms | |||
The next common value up is '''100 ohms''' so the actual current is 1.9v / 100 = '''19mA''' | |||
Next step is to figure the wattage: | |||
P = V x I = 3 x 20mA = 60mW so a 1/8W will work fine | |||
P = V x I = 1.9 x 19mA = 36mW so again you can use a 1/8W | |||
'''When using 12vdc:''' | |||
R = V / I or (12v - Vf) / .02 | |||
Assumption is 20mA for the LEDs (this is what they are from the group buy) | |||
Assumption is 2v for Red and 3.1v for Green, Blue and White | |||
Red - (12v - 2v) / .02 = 10v / .02 = 500 ohms | |||
Next common value up is '''510 ohms''' so the actual current is 10v / 510 = '''19.6mA''' | |||
GBW - (12v - 3.1v) / .02 = 8.9 / .02 = 445 ohms | |||
The next common value up is '''470 ohms''' so the actual current is 8.9v / 470 = '''18.9mA''' | |||
The next step is to figure the wattage: | |||
P = V x I = 10 x 19.6mA = 196mW so a 1/8W (125mW) will not work - you will need a 1/4W for Red. | |||
P = V x I = 8.9 x 18.9mA = 168mW so again you need a 1/4W. | |||
Revision as of 06:23, 29 May 2011
Kostyun RGB+W LED Super Strip Flood
- NOTE - THIS PAGE IS A WORK IN-PROGRESS - IT IS NOT COMPLETE YET *
What is the Super Strip Flood? The strip was designed and is sold by Frank Kostyun and is available on his web store at http://store.kostyun.com/product.php?id_product=34 as a pack of three strips. The Super Strip Flood is a 3/4" x 18" long strip that can hold up to eighteen RGB SuperFlux LEDs and an additional eighteen White SuperFlux LEDs (hence the RGB+W moniker).
Typically the RGB LEDs are common anode to support typical usage with DCSSRs or other DC controllers that implement switched grounds and common positive voltage. The circuitry has each LED/color with a series current limiting resistor and all LED/resistors are in parallel for each color. While this increases the number of resistors required, it does allow operation with just 5v as well as allowing you to partially populate the strip. The strips are usually run with either 5v or 12v as these are common DC power supply voltages. The use of 5v supplies allows smaller resistors (1/8W) to be used whereas the use of 12v supplies requires larger (1/4W) resistors.
The values of the limiting resistors can be calculated using Ohm's Law:
When usng 5vdc: R = V / I or (5v - Vf) / .02 Assumption is 20mA for the LEDs (this is what they are from the group buy) Assumption is 2v for Red and 3.1v for Green, Blue and White
Red - (5v - 2v) / .02 = 3v / .02 = 150 ohms 150 ohms is a common value so the actual current is 3v / 150 = 20mA
Green/Blue/White - (5v - 3.1v) / .02 = 1.9 / .02 = 95 ohms The next common value up is 100 ohms so the actual current is 1.9v / 100 = 19mA
Next step is to figure the wattage: P = V x I = 3 x 20mA = 60mW so a 1/8W will work fine P = V x I = 1.9 x 19mA = 36mW so again you can use a 1/8W
When using 12vdc: R = V / I or (12v - Vf) / .02 Assumption is 20mA for the LEDs (this is what they are from the group buy) Assumption is 2v for Red and 3.1v for Green, Blue and White
Red - (12v - 2v) / .02 = 10v / .02 = 500 ohms Next common value up is 510 ohms so the actual current is 10v / 510 = 19.6mA GBW - (12v - 3.1v) / .02 = 8.9 / .02 = 445 ohms The next common value up is 470 ohms so the actual current is 8.9v / 470 = 18.9mA
The next step is to figure the wattage: P = V x I = 10 x 19.6mA = 196mW so a 1/8W (125mW) will not work - you will need a 1/4W for Red. P = V x I = 8.9 x 18.9mA = 168mW so again you need a 1/4W.