[Noisebridge-discuss] A simpler circuit for ... [driving multiple LEDs with minimal batteries]

[Christoph Maier]

On Wed, 2011-01-19 at 09:59 -0800, Dr. Jesus wrote:
> On Wed, Jan 19, 2011 at 9:21 AM, T <t at of.net> wrote:
> > IYHO, why focus on linear regulators?  As Jonathan Foote pointed out,
> > they aren't really more efficient than a simple resistor.  Are they
> > simpler in any sense?
> >
> > If you want efficiency (which IMHO is a must when powering with
> > batteries) don't you need a boost or buck or other switching supply? 
> Sure, if I'm the one doing the design.  However, there's an entire
> class of people at Noisebridge who just want some power for an art
> project and they're more interested in cheap and fast than efficiency.
>  If you have a simple switching supply you want on the poster, draw
> one up!

http://www.diodes.com/datasheets/ZXSC380.pdf , Figure 2.

Doesn't get much simpler than that (and Tony found and posted the most
simplest implementation recently):
http://www.ledsales.com.au/catalog/index.php?main_page=product_info&cPath=131_132&products_id=384

Different question:
How do you make an iterative optimization heuristic _stop_ when it has
found an optimum?

Christoph