Hello
I have been searching in the web for ways to power LEDs without the always-needed resistor, and I found this great article here :
http://www.fieldlines.com/index.php?topic=131287.0and this other one where a good explanation of LEDs without limiting resistors :
http://tinkerlog.com/2009/04/05/driving-an-led-with-or-without-a-resistor/I would like to, if it is not so much to ask, for confirmation that my design could work, and will not burn the LEDs in matter of hours
Please let me take a couple of minutes of your time
the design a C I I C letters, first one horizontally flipped, the Cs are (intended to be) made of 50 LEDs and the Is of 40 LEDs, the LEDs are to be mounted in tiny plastic stripe, and it should keep as clear design as possible (therefore the intention of not adding more components than just the necessary ones)
the circuit should be powered from a car battery, sometime, form the car itself
so, to power it I thought to use a DC to DC conversor to apply exactly the voltage that LEDs need (I will play in the safe side, and keep 80% of it)
The LEDs I intent to use are :
http://www.ebay.com/itm/190522746092 Forward Voltage (V) : 3.0~3.2
Forward Current (mA):20
And the DCtoDC converter :
http://www.ebay.com/itm/260757400857 Wide range of input 3.0-33.5v
Stable & High efficient up to 92%
Powerful max.3A / Adjustable output 4.5-35v
Max. input up to 35v and output up to 35v
And the design, (sorry for the kindergarden-paint-style) something like :
Mathematically,
50 LED in parallel, 20mAh * 50 = 1 A
40 LED in parallel, 20mAh * 40 = 0.8 A
so load for the DCtoDCD 1.8 A
voltage output for the DCtoDC 3V + 3V = 6V
and as the DCtoDC range is 3A
Should this design works ?
Should I split both branches, the Cs to one DCtoDC converter, and the Is to another DCtoDC conveter ?
Should I add some resistors (please do not ask me to place 180 resistors in the circuit) ?
u other components ?
Should I aim for another configuration that would work better ?
thanks a lot for your help,
I would not like to spend long time soldering to discover the whole thing burns when powering up.