[geeks] my first electronics project

[Francois Dion]

On 8/4/05, Atom <rescue at port11.net> wrote:
> On Aug 3, 2005, at 9:59 PM, Bill Bradford wrote:
>
> > I figure I needed to learn how to properly use a soldering iron in
> > order to
> > keep my geek credentials.
> > http://www.flickr.com/photos/mrbill/sets/693178/
> Words of advice if you want to do some serious soldering.
>
> - Get a nice iron. Weller makes a pretty nice one in the $99 range
> (WES-50). Analog control but solders pretty nice

SMD is where it makes the most difference, but it is easier if you
have a nice iron with temperature control. I couldn't afford a decent
one until I got into university. But I'll mention that I was able to
do quite a few complex kits with cheap irons.

In particular, I remember when I was 14 or 15, me and 2 friends in
high school, decided to compete in:
http://www.exposciencesbell.qc.ca
We decided to build a robot. Weeks of sleepless nights and we almost
pulled it off. The robot was built on a copper pipes frame (talk about
variety in soldering skills!), with a record player turntable for the
rotation, T arm made with copper tubes with 2 bearings with a
counterweight on one end and a clamp grip on the other, made from
aluminium. This would have been pretty impressive in itself, but the
stepping motors were all controlled by a card we had designed. Using
regular motors and a switchboard was cheating in my mind. Of course we
might have won had we done that.

Instead, we went the complex way. We wanted something computer
controlled, unattended. We had a passive backplane, and each card was
controlling a motor. There was also a power supply card, a demux card,
an IR receiver card. On the computer side (an Apple II clone) we had
interfaced an IR emitter, using the joystick port on the motherboard
(this was not just an input port for joystick pots and buttons, it
also had TTL annunciators).

We soldered everything using this:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTL
G%5F011%5F009%5F007%5F003&product%5Fid=64%2D2070

And of course it didn't work right, but not because of the soldering.
Everything up to the stepping motor controllers was working. Plug in
the motors and it didn't. Post mortem 2 years later, once we knew what
we were doing: not enough power to supply the steppers, and no
freewheeling diode. Carnage. (We did recycle many parts to make an
electronic spectrometer(!)).

The winner that year was a hands free phone. Of course, this was
sponsored by Bell Canada... None of us ended up working in robotics,
or even in electronics. We all ended up working with computers tough.

I also have another noteworthy soldering iron story. In 1986, I went
to Expo 86 in Vancouver with my parents (from Montreal, in an RV). We
then went down to california. The way back was going to be long so I
stopped at Dick Smith Electronics (they are no longer in the US):
http://www.dse.com.au
And picked up a few amplifier kits:
http://www.dse.com.au/cgi-bin/dse.storefront/42f37f4e0a49fe762740c0a87f9c0755
/Product/View/K3431
this one looks much simpler in design than the one I had back then,
the component count was at least 2-3 times that one (and you'd need
two of them, and 2 power supplies, at a minimum)

The van didn't have 110v, just 12v, so I had to pick up a 12v soldering iron:
http://www.dse.com.au/cgi-bin/dse.storefront/42f37854093227de273fc0a87f9c06ea
/Product/View/T2100

They worked for many years. When one failed, a few years back I
emailed them to see if the schematics were still available, and not
long after that I received a manilla enveloppe from Australia, with a
set of schematics. That's service!

What prompted my interest in electronics was because well before my
teen years, my parents got me a radio shack kit (solderless type). I
did the same for my daughters, giving them solderless kits (with
breadboard) that I made, housed in hard shell crayon boxes. Hopefully,
that will spark their interest toward technical things.

Francois