I'm going to be powering 33 LEDs in series of 3 from a 12v battery that may range from 11-14v. The LEDs are 2.6v, 70mA. That's 7.8v at 770mA.
Here is the LED datasheet. HPWT-DH00.... Page 5:
www.philipslumileds.com/uploads/3/DS05-pdf
Here is the Linear Regulator I am looking at, .5v drop out, 1A:
http://www.newark.com/national-semiconductor/lm2940ct-9-0-nopb/voltage-regulator-ic/dp/41K4578
That's 2.31 watts of dissipated energy on the regulator and about 1 watt over the 11 resistors.
Is that too much dissipated power? I don't really have any idea what to base it off of.
I'd like to use 4 in each series and only have about a tenth of a watt of dissipated energy but I don't see how to get a constant 12v from a 11-14v range. I can't find any switching regulators that preform such magic.
This is not for a vehicle.
Thanks
Here is the LED datasheet. HPWT-DH00.... Page 5:
www.philipslumileds.com/uploads/3/DS05-pdf
Here is the Linear Regulator I am looking at, .5v drop out, 1A:
http://www.newark.com/national-semiconductor/lm2940ct-9-0-nopb/voltage-regulator-ic/dp/41K4578
That's 2.31 watts of dissipated energy on the regulator and about 1 watt over the 11 resistors.
Is that too much dissipated power? I don't really have any idea what to base it off of.
I'd like to use 4 in each series and only have about a tenth of a watt of dissipated energy but I don't see how to get a constant 12v from a 11-14v range. I can't find any switching regulators that preform such magic.
This is not for a vehicle.
Thanks