<div dir="ltr"><div>That's amazing! I had no idea the uO solar car generated that much current!<br>What kind of motor was all that power being used to drive? I was under the impression it was a tiny motor running at high RPM and geared down for torque.<br>
</div><div><br></div><div>Zot's a pretty cool nickname, though. ;)<br></div><div><br></div> -Jason Cobill<br><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Jun 24, 2013 at 4:49 PM, Richard Guy Briggs <span dir="ltr"><<a href="mailto:rgb@tricolour.net" target="_blank">rgb@tricolour.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Mon, Jun 24, 2013 at 04:00:51PM -0400, Jason Cobill wrote:<br>
> Experiments gone wrong? Tools gone out of control? What's the dumbest<br>
> thing you should have caught before you nearly set your house on fire? What<br>
> did you learn from it?<br>
><br>
> Me first: I plugged in a table saw without checking the switch first -<br>
> it was on. And it was covered in 2x4s and sheetwood scraps, which it<br>
> proceeded to launch across the garage and nearly take out a window.<br>
> It _should_ have been off, but I _should_ have checked. So now I check.<br>
> Every. Time.<br>
<br>
</div></div>Oh, this one's easy. ;-) I have two related to electricity.<br>
<br>
<br>
1) When I was about 10 I had a power transformer that I had taken out of a<br>
wood-cabinet vacuum tube TV set. I had learned to solder when I was about 8.<br>
I knew which side was the primary and I wanted to test the secondaries. I knew<br>
they would be high. I had a cheap analog multimeter from Radio Scrap with a<br>
750V rating. I carefully attached and shielded the primary wires to a<br>
standard two-prong plug. I was sitting on my bed (so no danger of<br>
grounding out, plus it was an isolated secondary). I pinched one<br>
secondary wire with the meter test lead, then grabbed the second test<br>
lead and went to pinch it with the other secondary... (It was about 350V.)<br>
I haven't done that ever again! Now I used insulated leads.<br>
<br>
<br>
2) In my last year of Electrical/Computer Engingeering at U of Ottawa,<br>
I was working on the U of Ottawa solar rayce car RALOS-II, wiring up the<br>
main power backplane of the car (I was the Electrical Systems<br>
Co-ordinator) working on some low-voltage wires on one card that<br>
happenned to be facing a high-voltage, high-current card connected to 7<br>
car batteries in series (90VDC, 1000A?). As I pulled my hands away from<br>
my work something sparked. Naturally I pulled back, jamming my family<br>
gold ring into the high-voltage card. Once the sparks stopped, two of<br>
my fingers were black. After a quick throw of the main power switch for<br>
the car to avoid any further incident, one of my teammates packed me off<br>
to the hospital to clean things up. On the way to the hospital, I was<br>
babbling with all the wire cross-sectional diameters, materials and<br>
resistances per metre still fresh in my mind, calculating that must have<br>
been a 100kW arc welding burn.<br>
I was lucky. I still have all my fingers, but one has an<br>
interesting ring-shaped scar (that was 20 years ago this month) and the<br>
bloodstone with the family crest in the ring cracked. I thought of<br>
getting it repaired, then decided to leave it as a reminder. I was very<br>
lucky it didn't instead hit the iron ring on the adjacent finger that I<br>
had earned not 2 months prior. Gold is a much better conductor, so it<br>
didn't heat up much compared with the other parts involved. The two<br>
one-inch spade terminals on the card along with 1/2" PC board traces<br>
vanished. I had to check a second identical card to find out what was<br>
there. I earned the nicname "Zot" for that one...<br>
I now remove my rings when working with high voltage/current.<br>
<br>
<br>
I still love electricity! :D<br>
<br>
<br>
> -Jason Cobill<br>
<br>
slainte mhath, RGB<br>
<br>
--<br>
Richard Guy Briggs -- ~\ -- ~\ <<a href="http://hpv.tricolour.net" target="_blank">hpv.tricolour.net</a>><br>
<<a href="http://www.TriColour.net" target="_blank">www.TriColour.net</a>> -- \___ o \@ @ Ride yer bike!<br>
Ottawa, ON, CANADA -- Lo_>__M__\\/\%__\\/\%<br>
Vote! -- <<a href="http://greenparty.ca" target="_blank">greenparty.ca</a>>_____GTVS6#790__(*)__(*)________(*)(*)_________________<br>
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