I want to design a driver circuit for power led. i have a solar panel from which i am charging my battery. my battery is of 12V. Now, i want to get 6W power so around 6 power led can be adjusted with it. or 9W or 12W power.
Basically, idea is to design a power LED circuit that can give sufficient output from my 12V battery.
since u require 6 WATT at the output u will use 6 high power LED of 1 watt each. use both series and parallel connection for LEDS (3 LED in series, thus u will have 2 rows and 3 column). As 3 LED are connected in series and each LED requires 3.3 volt, U will require total of 9.9 volt at the output and output current will come around 600 mA. For this circuit u will require BUCK CONVERTER i.e DC-DC STEP DOWN CONVERTER because output voltage requirement is less then input voltage. There are many IC's available in the market, u can choose any one.. Go to TI.COM site and search for DC-DC CONVERTERS u will get IC'S along with the circuit diagram.
@HIREN DAVE:what is your battery capacity(mAh) ?????
---------------------------------For some reason a post on battery capacity of 40 Ah was deleted-----------------------------------------
40 AH is a pretty big battery seeing that you only want to extract 6 W from it.You may need to think about maintaining constant current & using current sense resistors.
You could also think about using Voltage Regulator,LM 317 & definitely a heat sink.
Peter,in post #4 he says he needs 6 W o/p power so that he can light 6 power led's.So he may be talking about 6 W only.
But again he said about 9 W & 12 W.
An LED driver,so LM 317 with a nice heat-sink could do it
However, LM317 is linear regulator and its not efficient for this design, if he want efficient design should use switcher regulator not linear. He didnt specify which led he want to use on which voltage.
OK my friend...
I want to design a driver circuit for power led. i have a solar panel from which i am charging my battery. my battery is of 12V. Now, i want to get 6W power so around 6 power led can be adjusted with it. or 9W or 12W power.
Basically, idea is to design a power LED circuit that can give sufficient output from my 12V battery.
@rahdirs: LM 317 can provide voltage regulation to power 6 watt LED but efficiency will be very poor. So he should go for pwm based driver where he can get efficiency >85%. so pwm circuit is required. and the pwm signal will be fed to mosfet, then output of the mosfet will be connected to diode and capacitor in parallel followed by a good LC filter. this way we can achieve better LED driver.