Alt-BEAM Archive

Message #05348



To: beam@sgiblab.sgi.com
From: Sean Rigter rigter@cafe.net
Date: Wed, 21 Jul 1999 20:28:33 -0700
Subject: [alt-beam] Re: solar cell v doubler


For one, the "single cell boost converter" is much more efficient than
the charge pump voltage doubler but not because of the 555. I could sub
a 74HC04 for the 555 and probably get similar performance although
perhaps not the <1V operating range useful for single (battery) cell
operation. The 555 converter circuit is kind of overshadowed by all
those external bits. It should be possible to design a cheap and simple
74HC14 true boost converter albeit not as efficient as the more complex
design. Check out Maxim for some of the best
(but not cheapest) solutions.

regards

wilf

television_is@mindless.com wrote:

> Wilf Rigter wrote
> "This voltage doubler circuit is often designed around a 555. "
> I found this circuit on the Zetex site about their 'new and efficient'
> zsct1555 which they say continues to supply 5 volts from down 0.9 volts
> in their voltage booster circuit. (attached)
> The page is at http://www.zetex.com/applic1.htm
> How can a circuit with so many bits be anywhere near as efficient as
> your charge pump Wilf?
> Is this 'new' 555 actually better than the cmos version?
>
> Rob
>
> ------------------------------------------------------------------------
> [Image]

------------------------------------------------------------------------

eGroups.com home: http://www.egroups.com/group/alt-beam
http://www.egroups.com - Simplifying group communications



Home