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Super LED Light 60LEDs@3.2V & 20mA on 9Volts

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zasto said:
Breaddown voltage is the max reverse voltage that LED can sustain without beeing damaged.
Click to expand...

So what you are saying is that i can connect the led in reverse and it will operate up to a certain voltage? I thought that if i connect the led in reverse that it actually blocks current.


On another note, ive been looking into led drivers for my 60 led system. I love the idea, i think it woukd make my project much more professional, but i dont know if i have the skill to put it all together, i have no experience with such "complex circuitry"
 

Thanks for all the answers guys!

Ive been looking at the LM317, my thoughts are converting 18V from 2 9V Batteris to 19.2V so i can have 6LED in one series. Im not sure how many of these series would i need,and what would the drain on the battery be.
But i guessing that that wont work anyways, so im asking you guys where i can get those ISL components for that LED Driver. Ive found a test board that i can use to make the circuitry so i figure if a can arrange the components on the board according to the diagram i can solder them in place and voila :)

Cheers!
 

Dulimir said:
Thanks for all the answers guys!

Ive been looking at the LM317, my thoughts are converting 18V from 2 9V Batteris to 19.2V so i can have 6LED in one series. Im not sure how many of these series would i need,and what would the drain on the battery be.
But i guessing that that wont work anyways, so im asking you guys where i can get those ISL components for that LED Driver. Ive found a test board that i can use to make the circuitry so i figure if a can arrange the components on the board according to the diagram i can solder them in place and voila :)
Click to expand...

You want to use 2 x 9V Lithium to make 18V (Lithium Rechargable nominal voltage is 9V, and for Lithium disposable nominal voltage is 9V).

Lithium disposable:

For 2x 9,6V = 19,2V You can put 6 LED without resistor or use 5 LED with resistor of 180R.
 
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    Dulimir

    Dulimir

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Here is what i am going to do.

i will go with 30LED configuration, 19.2 volts powering 5 series of 6 LED's, a basic on off switch and a potenciometer.
I dont expect great battery life, but consuming 100mA is way better than 600mA that my old plan called for.
 

Of course You can try. If everything ok and time of battery life is good, then ok. Maybe later You wish to make Ver 2 of this with some led driver. ;-)
 
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    Dulimir

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Ive been looking at the design with the two condensators and two transistors, i could do that easily, but i dont know how to calculate which ones i need for my voltage and my LED's...
 

Dulimir said:
Ive been looking at the design with the two condensators and two transistors, i could do that easily, but i dont know how to calculate which ones i need for my voltage and my LED's...
Click to expand...

Its easely, first make this on protoboard then meassure voltage on out, then use led resistor calculator to see what resistor value and how much leds you can use there in one serie.

protoboard_med.jpg
 
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Ok, so here is version 1 of my project.
36LED in 4 series of 9 , this circuit drains 80mA from the source. My next version is going to use an LED driver, thats if i can find one that i can use.
Here is the schematic for the "LED's for dummies" :p with annotation! Ill post pics when i actually build this, somewhere in the next 2 weeks, im still waiting for some components to arrive.
leds.png
 

Hey guys, ive finished the first prototype, i changed the setup again hehe, now its 30 LED's, 5 series of 6 running on 2 9,6V block batteries. I also used a variable resistor to control the brightness. I didnt want to spend alot of cash on the potenciometer, so its a bit too strong, but was really cheap. I turn it about a quarter way to go from full bright to dim, so its a bit fidly but managable.
Here are the pics...
DSC02649.JPGDSC02650.JPGDSC02651.JPGDSC02652.JPGDSC02654.JPGDSC02655.JPGDSC02656.JPGDSC02657.JPG
 
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    tpetar

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Dulimir excelent job! Very amazing nice job! I supose that all girls now looking for you. ;-)

As additional You can put some white transparent silicon between leds to make waterproof.

Nice job.
 

Hahaha, thank you! My fiancee actually said it looked like i had bought it in a store :p I am thinking of somehow protecting the LED's from external influence and reflecting and difussing the light at the same time. But after a few tests, i realized that the LED's are not strong enough. So my next try i will use Nichia LED 5mm white 44000mcd, the ones i have now are only 10000mcd. The Nichia LED's are a bit more expensive, but i think it will be worth it. So far, the battery has been holding up too-but i think i will have to work on my efficiency alot more.

A question for you tpetar: Is it more efficient to step up voltage, and does that draw less current from the battery. So what i am asking is, if i step-up the voltage from the 9v batteries, will a get better batterie life?
 

Always is better to get power from higher voltage and lower current, but voltage booster (dc/dc converters) not 100% efficient. If You whant to boost voltage from 9V to some higher voltage consider additional lose of power. Better use two batterie in serie.

Maybe consider usage of this NiMh with case, You can always recharge:

_Battery_Holder_4xAA_Square.JPG099-038.jpg

There is also complete closed battery case for up to 12 batteries.
 
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i was thinking of using 3 9v is series, so 28.8V and step that up as much as i can, so idealy i have one series of 30LED at 96V :) can that be done ?
 

Of course this can be done, check breakdown voltage of that led in led datasheet and choose right dc/dc booster.


But I think that this voltage is to high. Safety on first place.
 
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yes, it is way too high :) so i have to balance between the voltage and number of series of leds.
If i could do it in two series, that would be 40mA on the battery, which is quite high for the 9V block i think. There bateries operate with very low current. So im guessing that most LED lights, like for a bycicle, use LED Drivers?
Does an LED driver step up voltage? how does that work really, and is it more efficient ?
 

This depends on many things. Usualy led driver regulate voltage and current for led. You need step up dc/dc booster, but efficiency varyabout 80-85-90% good.


Sorry I will back in few minutes, my miniature pincher dog goes crazy whants out.
 
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