Alt-BEAM Archive

Message #07786



To: beam@sgiblab.sgi.com
From: Thomas Pilgaard Nielsen [mailto:ascii@hum.auc.dk]
Date: Wed, 17 Nov 1999 12:12:23 +0100
Subject: Re: More PCB etching



"Van Zoelen, Bram AA SSI-TSEA-352" wrote:
>
> That depens on how steady your hands are.
> If i wants to make really fine traces then i cover
> the complete area with an etch resistance pen and
> then i use a knife to scratch or cut paths in the
> cover. This way i can make very fine traces. Example: i can make 3 lines
> between two IC pins this way.

Uuh - ok, I reckon that requies some skill (ie. skills i !don't! have)

A local retailer has some sort of transparent cover that you cant
laserprint your cirquit on - then iron it onto the printboard and then
etch it. It sounds fairly simple though I'm not sure of the quality.

From what you write i understand it's not like in the etching process
the whole thing would be gone just like that due to lines that are too
thin?

Thanks for the reply,

Thomas, Denmark


>
> Bram van Zoelen
> Robotics, kites, personal and more
> http://vsim.freeservers.com
> http:/beam.to/vsim
>
> E-mail
> vsim@mail.com
> vsim@vsim.freeservers.com
>
> -----Original Message-----
> From: Thomas Pilgaard Nielsen [mailto:ascii@hum.auc.dk]
> Sent: Wednesday, November 17, 1999 9:17 AM
> To: Beam Mailing List
> Subject: More PCB etching
>
> Hi all,
>
> since I have only had little previous experience in etching PCB's I was
> wondering how fine one can mask the traces. How thin can I make each
> trace and how much space would I need to leave between them.
>
> Naturally I am talking about etching it at home using some kind of
> chemical. Would there be differences in the possibilities of these
> chemical or is that just plain vanilla?
>
> Cheers and all,
>
> Thomas, Denmark
>
> --
> ---
> "Fremtidens computere vejer maaske ikke mere end halvandet ton."
> Popular Mechanics 1949

--
---
"Fremtidens computere vejer maaske ikke mere end halvandet ton."
Popular Mechanics 1949



7787 Wed, 17 Nov 1999 08:49:14 -0600 [alt-beam] Re: SPLIT BICORE POWER beam@sgiblab.sgi.com Richard Piotter Make sure the voltage is appropriate for the motors. Using this method
is how my 3 motor walker "Bronco" got it's name. Just think about that
name for a moment! :)

"Van Zoelen, Bram AA SSI-TSEA-352" wrote:
>
> Yes.
>
> Bram van Zoelen
> Robotics, kites, personal and more
> http://vsim.freeservers.com
> http:/beam.to/vsim
>
> E-mail
> vsim@mail.com
> vsim@vsim.freeservers.com
>
> -----Original Message-----
> From: Mike Kulesza [mailto:mikekulesza@hotmail.com]
> Sent: Wednesday, November 17, 1999 1:04 AM
> To: beam@sgiblab.sgi.com
> Subject: SPLIT BICORE POWER
>
> Can i run 5V to the 240 through a 7805 volateg regulator, and supply the
> full 9V to the h-bridge?
>
> that will keep the chip safe, and increase the motor power
>
> ______________________________________________________
>


7788 Wed, 17 Nov 1999 07:12:17 -0800 [alt-beam] Re: Chloroplast-o-mania! "'beam@sgiblab.sgi.com'" Wilf Rigter Well it was a clear case of parallel evolution I send mine just as I
received yours. Difference? Not much to look at but you may be =
surprised
they are based on completely different principles (remember small =
changes,
big effects). In the Chloroplast Thingy, the motor driver with the most
light turns ON and in the PhotoChlor the driver with the most light =
turns
off! Notice that in your design the PDs are facing the right way ie as =
PD
with leakage current proportional to light level. In my design they are
upside down ie as small solarcells generating voltage and current.=20

The Chloroplast Thingy

The effect of using the PDs as PDs can be likened to using two parallel =
500K
potentiometers: the base current and the drive currents are =
proportional to
light and the switching between drivers is soft. Any light on the PDs: =
both
are on. Variation in light : 10 to 1 variation in base current. Medium
light: slow speed. In the dark: no juice.=20

The PhotoChlor

The effect of using the PD as a photovoltaic generator (PV) can be =
likened
to using two variable zener diodes in parallel: the PV with the lowest =
light
has the lowest zener voltage and gets all the base current: switching
between drivers is non-linear and relatively abrupt. Any light on the =
PV :
the PV with the lowest light is switched "on". Variation in light: no =
more
than 2 to 1 variation in base current.=20

Anyway it's a bit theoretical at this stage since the photochlor has =
not
been proven but may the best tech win, eh!=20

regards

Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493=20
fax: (604)590-3411

> -----Original Message-----
> From: Richard Caudle [SMTP:richard@cqc.com]
> Sent: Tuesday, November 16, 1999 5:57 PM
> To: beam@sgiblab.sgi.com
> Subject: Re: Chloroplast-o-mania!
>=20
> Ok Wilf,
> =A0
> I'll bite.=A0 What's the difference between my phototropic =
chloroplast and
> yours?=A0=20



7789 Wed, 17 Nov 1999 09:32:09 -0500 [alt-beam] Re: absorbpsion circuit or something beam@sgiblab.sgi.com "Peter A. Low" Haven't you seen The Matrix? You just need to use a whole lot of people in
their special battery pods. ;o)

At 01:02 PM 11/17/99 +0100, you wrote:
>Hi
>
> >I was reading an article about Cyborgs a few years ago and there was a
> >collage kid in the mid west that claimed he could run his PC off the
> voltage
> >that surrounds the human body... I think it was either a coil receiver or
> >possibly a skin contact battery that used the wearer as the dielectric???
> >but the article did not say... just a strong statement of "fact"... ?????
>
>The human body burns about 100 to 200 Watts energy ... dependent on what it
>is doing. Is it possible to convert this warmth to electricity .. don't
>know how efficient that could become, but I doubt it will provide enough
>for a PC to run on.
>
>Wouter

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