Hello,
I need help determing the PROPER/BEST way to light up a bunch of led's. I've done a BUNCH of reading on this forum, but haven't been able to determine my best option yet. These are being installed in a vehicle with a massive power supply (5 batteries, HO alternator, plug in charging capacity, etc). Voltage in the vehicle will range from 11.5 - 14.5 volts. It may rarely dip below the 11.5 from time to time, but I'm not too concerned if the LED's dim or go out at that time. Once the LED's are installed, they will take hours and hours of work to replace should they burn out. As such, I want to get the circuit right the 1st time!
What I need is to figure out what to control, the voltage, the current or both and how to do that.
I have a bunch of NTE956 (lm317) on hand and all the resistors I could ever need. I also have some generic NPN and PNP transistors. I can get other stuff as needed but would like to make use of what I have already.
There are about 70 LED's total. About half are green, about half are white.
Specs for WHITE LED's:
5mm FLAT TOP Wide Angle 20,000 mcd LEDs
Reverse Current (uA) : <=30
Absolute Maximum Ratings (Ta=25°C)
Max Power Dissipation : 80mw
Max Continuous Forward Current : 24mA
Max Peak Forward Current : 75mA
Reverse Voltage : 5~6V
Specs for Green LED's:
If=25mA
Min voltage 3.0
Typcial voltage 3.2
MCD 14,000
reverse current w/ Vr=5V = 10 uA
( the led's came from different sources and each source only listed the above info)
I would like, if possible, to wire strings of 3 leds (of the same color) in series and then parallel them together or run each string to a "device"
What I need to know if how to do this the best way possible?
Can I run 36'd led's off one device (12 strings with 3 in series per string?) Do I use one nte956 to control the current and another to control the voltage. Do I need resistors? Will each LED color require different resistors? I am not good with figuring this stuff out, so a drawing would be most helpful!
Oh, and of course, I need to try to get this done asap.....
THANKS!!!!!!!!
I need help determing the PROPER/BEST way to light up a bunch of led's. I've done a BUNCH of reading on this forum, but haven't been able to determine my best option yet. These are being installed in a vehicle with a massive power supply (5 batteries, HO alternator, plug in charging capacity, etc). Voltage in the vehicle will range from 11.5 - 14.5 volts. It may rarely dip below the 11.5 from time to time, but I'm not too concerned if the LED's dim or go out at that time. Once the LED's are installed, they will take hours and hours of work to replace should they burn out. As such, I want to get the circuit right the 1st time!
What I need is to figure out what to control, the voltage, the current or both and how to do that.
I have a bunch of NTE956 (lm317) on hand and all the resistors I could ever need. I also have some generic NPN and PNP transistors. I can get other stuff as needed but would like to make use of what I have already.
There are about 70 LED's total. About half are green, about half are white.
Specs for WHITE LED's:
5mm FLAT TOP Wide Angle 20,000 mcd LEDs
Reverse Current (uA) : <=30
Absolute Maximum Ratings (Ta=25°C)
Max Power Dissipation : 80mw
Max Continuous Forward Current : 24mA
Max Peak Forward Current : 75mA
Reverse Voltage : 5~6V
Specs for Green LED's:
If=25mA
Min voltage 3.0
Typcial voltage 3.2
MCD 14,000
reverse current w/ Vr=5V = 10 uA
( the led's came from different sources and each source only listed the above info)
I would like, if possible, to wire strings of 3 leds (of the same color) in series and then parallel them together or run each string to a "device"
What I need to know if how to do this the best way possible?
Can I run 36'd led's off one device (12 strings with 3 in series per string?) Do I use one nte956 to control the current and another to control the voltage. Do I need resistors? Will each LED color require different resistors? I am not good with figuring this stuff out, so a drawing would be most helpful!
Oh, and of course, I need to try to get this done asap.....
THANKS!!!!!!!!