Good usage Bright Light LEDs 5W or 10 Watts

[engineerpervez1]

Good usage of 5W or 10 Watts Bright Light LEDs

In my countary home power supply fail oftenly.
I want to make use of bright light LED 5 watts or 10 Watts, but these LEDs
are very current sensitive,
I want to run 5 watts LEDs 5 numbers of LEDs, run on 12 Volts DC battery.
LEDs current is 350 milli amp.
I want to make a series circuit of 5 leds, The led I got this have a working volts 6
so for 5 leds total voltage will be 30 Volts DC.
It will be a boost circuit.

If some body have some good circuit, Pl provide me.
thanks:razz:

 

[randallfarmer]

Why not just parallel them across the supply voltage and put each one one a current limiting resistor? You will have to take note of the high power rating of each resistor. Can you post a schematic of what your trying to do?

 

[engineerpervez1]

we use these LEDs in series because there is some sensing circuit (normally a low value resistor). if we put many line of LEDs parallel combination many sensing
resistor and sensing circuit to be incorporate, that will be more difficult.
simply light-up LEDs with regulated supply is no problem.
but this is not long lasting circuit.good circuits are which continously wacth the
current.that type of circuit is required.
LEDs which I have it 6 volts on 12 volts I only light up 2 LEDs. I want more LEDs

 

[swordfish01]

Hi,

Is there a problem in using a standard DC/DC converter IC for this? You could have a look at e.g. Linear Technologies, National Semiconductors or Texas Instruments, just to name a few companies. All of them produce pretty easy to use DC/DC converters, mostly with pretty explanatory datasheets. Some of the even provide simulation tools for their own parts.

Most of the time you will be able to find a usable circuit for you requirements in the datasheets to the parts.

Regards,
Andreas

 

[asimov]

Well, one can use dc-dc convertors but generally these small IC ment to run LEDs are in smd package and are hard to solder and are about 2-3$ each(expensive for hobby purpose), Why not make a small chopper circuit using NE555(PWM) and some reference source likt TL431 to maintain a constant current. I had designed on such circuit(on paper but never got the time to build it!!!)

Asimov

 

[swordfish01]

Hi,

Since the topic is in the "Professional Hardware and Electronics Design" Section, I wasn't thinking of some circuit hacking... We could discuss your "hard to solder" point, but I think that in general it should not be a problem to solder an SOIC or a TQFP, we do that on milled test-PCBs all the time.(Though a nice PCB with solder mask etc. is a great help). But if you're not used to it you might have problems...
Otherwise a nice idea, you'll maybe have to spend some thoughts on stability. OTOH, a DC/DC converter gives you a lot more functionality (over current protection, over temperature protection, fast FET drivers, etc.), but basically they are nearly the same circuit as you proposed, only with some additions. The cheapest parts I could find are from Texas Instruments a little more then 1$, which is indeed more then your solution will cost.

In the end it all depends on your needs/your application, which variant to choose...

You might also get along with some voltage doubling circuits and regulation afterwards, depending what you can do with your sensing circuits afterwards.

As I said, like most of the time, which solution is right highly depends on your needs/your application.

Regards,
Andreas