poolman966554
Newly Enlightened
- Joined
- Oct 20, 2010
- Messages
- 77
opinions on ways to wire led series in "high/low" mode/ and cooling question
hello everyone. Ive been working on putting together an xml light bar for a while now.
Im still waiting for supplies, and with this 'wait' time, i keep thinking of more stuff i could try.
To get up to speed, im building a (now) 12 xm-l led lightbar running 4 xml in series with a .68 ohm resistor and a TVS(suggested by DIWdiver)
specs say xm-l2 @ 700lm is 3.2v @2300ma
math says that on a 14.4v supply, i need a .68ohm resistor.
how about this idea? Id like the 2300ma as a "low" mode and run them at 3A on "high" mode - like this-(pardon my fancy Mspaint skills)
So orange being low, and yellow being high, this should work right?
If so, i still have no idea what diode i need to separate the .68ohm and the .3ohm resistors.. or will it be cheaper to just run a rocker with separate resistors? I could do that, but it will require more space inside the u channel,and id rather no make things tight. Also, Im just trying to work with what i have on hand..
Also i realize the voltage will increase to approx 3.3v with the amperage increase, so figured that in to make the resistor output at .4ohm
Another opinion if i may ask..
For cooling, i have 3 old P4 processor heatsinks (fins are 2" tall, 1/16"wide) i am planning to cut down middle and bolt to the entire length of my u channel (approx 16" x 2") with artic silver 5. (fins mounted vertically) Will this be sufficient?
btw, this circuit will also have a fuse as well, forgot to add it.
Thanks guys!
Edit: upon reviewing circuit, i realize my resistor values may change.. will this high/low separation diode have a resistance value to it? if so, how much will/might it throw off my calculations?
hello everyone. Ive been working on putting together an xml light bar for a while now.
Im still waiting for supplies, and with this 'wait' time, i keep thinking of more stuff i could try.
To get up to speed, im building a (now) 12 xm-l led lightbar running 4 xml in series with a .68 ohm resistor and a TVS(suggested by DIWdiver)
specs say xm-l2 @ 700lm is 3.2v @2300ma
math says that on a 14.4v supply, i need a .68ohm resistor.
how about this idea? Id like the 2300ma as a "low" mode and run them at 3A on "high" mode - like this-(pardon my fancy Mspaint skills)
So orange being low, and yellow being high, this should work right?
If so, i still have no idea what diode i need to separate the .68ohm and the .3ohm resistors.. or will it be cheaper to just run a rocker with separate resistors? I could do that, but it will require more space inside the u channel,and id rather no make things tight. Also, Im just trying to work with what i have on hand..
Also i realize the voltage will increase to approx 3.3v with the amperage increase, so figured that in to make the resistor output at .4ohm
Another opinion if i may ask..
For cooling, i have 3 old P4 processor heatsinks (fins are 2" tall, 1/16"wide) i am planning to cut down middle and bolt to the entire length of my u channel (approx 16" x 2") with artic silver 5. (fins mounted vertically) Will this be sufficient?
btw, this circuit will also have a fuse as well, forgot to add it.
Thanks guys!
Edit: upon reviewing circuit, i realize my resistor values may change.. will this high/low separation diode have a resistance value to it? if so, how much will/might it throw off my calculations?
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