The Tuesday 2004-10-12 at 08:13 -0500, Steve Kratz wrote:
I can vouch for the fun of the charge-capacitor trick... Learned that from a high-school physics teacher that got tired of people stealing parts from the electronics drawers before class. He simply charged the caps, left them in the drawer, end of problem :)
X-) On a university lab, we had to design and test a multimeter. One part was the AC voltage measurement. We used a potentiometer to get a variable voltage from the 110 volts "safe" lab ac supply (remember that the standard here is 220). One chap reversed the connections, so that the wiper was connected to the live side, instead of being the output. When he turned it down, it went on fire, of course. The funniest thing was watching his face while he wondered what he dad done, and not having the foggiest idea. On that same lab, electrolytic capacitors were preconnected below a small plastic board with metal legs, so that the connections were upside, and the capacitor was downside. The lab technician said he was tired of painting the ceiling every term. I can testify to one blowing up, next year, while I had volunteered to help at the lab. I wasn't fast enough to stop the newbie from connecting the cap (he was supposed to ask me to check his connections first). -- Cheers, Carlos Robinson