Alt-BEAM Archive

Message #05349



To: beam@sgiblab.sgi.com
From: "Travis D." beam_bot@yahoo.com
Date: Thu, 22 Jul 1999 00:38:02 -0400 (EDT)
Subject: [alt-beam] Re:solar cell v doubler


Maxim's web site also had one based around their
860...

--- 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
>

> ATTACHMENT part 2 image/gif
Attachment: ell.gif 5350 Wed, 21 Jul 1999 21:45:40 -0700 [alt-beam] Re: Hoverbot & balancing acts ( was: LEGO lawnmower) beam@sgiblab.sgi.com Bruce Robinson Wilf Rigter wrote: > > Nice topic Zoz! > > Try a 2DOF balancing act with a 4 foot rod on the tip of your finger. > Note that your eyes, focused on the position of the tip (top) of the rod, > are the feedback sensors. Well, the eyes are the feedback sensors you're conscious of. Their are dozens of proprioceptive feedback sensors in your arm and finger muscles. They are so good at making small adjustments that you are unaware of them. > At first I experienced some wild excursions of the bottom of the rod > while the tip moved relatively little but after some practice, the > correction signals (bottom swings) became smaller ... Due to

The mechanical equivalent: multiple control devices with different types
of feedback and different sensitivities.

So ... how does a BEAM device "learn" motor skills? Aside from us humans
tweaking pots and so on? That's the real challenge here, isn't it?

Regards,
Bruce



5351 Thu, 22 Jul 1999 00:41:25 -0400 (EDT) [alt-beam] Re: solar cell v doubler beam@sgiblab.sgi.com "Travis D." Do you loose any current in the process of doubling
the voltage???

--- Sean Rigter wrote:
> 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]
>



5352 Thu, 22 Jul 1999 00:57:14 -0400 [alt-beam] Re: Hoverbot & balancing acts ( was: LEGO lawnmower) beam@sgiblab.sgi.com "George Rix" > So ... how does a BEAM device "learn" motor skills? Aside from us humans
> tweaking pots and so on? That's the real challenge here, isn't it?
>
> Regards,
> Bruce
>
Is there any type of pot which would adjust itself? Other than light and
thermal sensors (though if you could use one of those to do this, I'd give
you a prize), I mean. I could see the addition of this to BEAM bots as a
major advance, but then, I don't really know. It just seems like a good
idea.
How would you implement such a pot into the bot, anyway? Perhaps have
whatever lead it has controlling the resistance (I'm making a few
assumptions, of course) connected to a mercury switch, so it could try to
keep its balance.
Just a few thoughts.
Signing off,
Rob Rix

'If anything can possibly go wrong, it probably already has'-Murphy's law



5353 Wed, 21 Jul 1999 22:13:42 -0700 [alt-beam] Re: solar cell v doubler beam@sgiblab.sgi.com Sean Rigter At 100% efficiency, the voltage doubling process would supply 2 times the
input voltage at half the current . Efficiency = power out/power in x
100%. However, the output resistance and switching losses always limit the
efficiency. The charge pump absolute losses are lowest (about 0.5mw) at zero
output but efficiency is 0% (0mw/0.5mwx100%=0%) The ucpump efficiency is
the highest when the output current is about 20-30ma (to be confirmed).

regards

wilf

"Travis D." wrote:

> Do you loose any current in the process of doubling
> the voltage???
>
> --- Sean Rigter wrote:
> > 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]
> >
>
> _________________________________________________________
> Do You Yahoo!?
>


5354 Thursday, 22 July 1999 2:23 Re: which SE to use? beam@sgiblab.sgi.com Craig Maynard
>I think the Chloroplast would be a great SE to use for your
>application... You can free-form it quickly and the parts count is
>quite low.
>
>You can see the instructions and a free-form wiring diagram at
>http://members.home.com/cybug/Chloro/chloro~1.htm .
>
>
>Craig
>
>
>----- Original Message -----
> From: David Perry
> To: beam@sgiblab.sgi.com
> Sent: Tuesday, July 20, 1999 2:06 PM
> Subject: Re: which SE to use?
>
> so, does anyone know which circuit i should use, i'd like to go
>with the d1 SE but i don't want to overcharge the gold cap and blow it
>up. But
> i'm not sure if the PM1 SE can handle these sorts of loads. any1?
>
> David Perry
>
>
> -----Original Message-----
> From: David Perry
> To: beam mailing list
> Date: Sunday, 18 July 1999 3:31
> Subject: which SE to use?
>
> ok the dilemna, not to release to many secrets but my
>caterpliller bot has 4 motors which draw around 70ma each, plus there
> is an additional circuit to make it make a cricket sound when
>dark (it draws 1ma while idle and 8ma while making annoying
> noise) plus a microcore w/ LED's (5) , 2 reversers and cold
>start PNC and 4 high power h-bridges and ahhh, thats about it.
> As you can imagine i really need a bigger robot to carry all
>the circuitry. Now to power it i have 2 24x33 solarcells and a
> 1farad cap. It hasn't really got a very stiff walking gate so
>losing sync ain't much of a problem. Now what sort of solarengine
> do i use? d1, which i don't want cause i'm impatient or a PM1
>SE? For emergencies i also have a .33 gold cap and 2
> 22x24mm solar cells which i might be willing to give up to use
>on this bot? Please help!
>
> David Perry

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