My project have increased in size since i started, and the LM3407 is no longer suitable for driving the amount of LEDs that i need. I need to drive 12 LEDs in series.

Input voltage must be one of these:
- 230VAC 50 Hz
- 15VAC 50 Hz
- 21VDC

The LEDs:
- 3V and 300mA
or
- 3.15V and 350mA


I would prefer to make circuit myself, but i kinda like the BoostPuck ( http://www.leddynamics.com/LuxDrive/datasheets/4015-BoostPuck.pdf ). High efficiency, easy to use and adjustable.


Anyone know a good circuit (with good efficiency = no LM317 circuit please)?
Or just a good off-the-shelf driver?


Thank in advance!

 

No one at all ?

 

Hello,

Perhaps take a look at the LM3409.
Make it for 600 - 700 mA, put two rows of 6 leds parallel
(a 4.7 Ohm / 1 Watt resistor in series with each row to compensate for led differences).

Greetings,
Bertus

 

Hello,

Perhaps take a look at the LM3409.
Make it for 600 - 700 mA, put two rows of 6 leds parallel
(a 4.7 Ohm / 1 Watt resistor in series with each row to compensate for led differences).

Greetings,
Bertus

Parallel isnt really an option. Adding a resistor will only add to lower effiency - which then removes some of the idea of using LEDs.

 

Hello,

Then take a look at the LM3421 wich is a boost converter.

Greetings,
Bertus

 

Hello,

Then take a look at the LM3421 wich is a boost converter.

Greetings,
Bertus

Looks quite okay - gonna give it a look! Sadly its only made in SMD too.. i like leaded compoents alot more - but it seems hard to find any of those. At least from NS.