I just cranked my 12 volt adapter into my high brightness LED to see if the adapter was working. That's without a resistor before the LED. Bad move.
The adapter sure as hell is working, but there is no more LED. As soon as i touched the ground wire to the LED there was an almighty SNAP, a flash of orange (the LED was red) followed by the LED exploding into 3 pieces. I could've lost an eye. Caught stupid me totally by suprise. hahahaha
...yea...
these kids in a basic electric class that i used to stop by once in a while in 9th grade used to have fun taking random components, usually caps and leds, taping them to a long ruler, and stickign them into the wall outlets. That always made a nice pop :-D
On the weekend I was using an MJE3055 (ie very rugged) tranny to drive the primary side of a car ignition coil (about 1.5 ohms with the secondaries "open"). By accident I closed the secondary. I don't know how much current it pulled (50A?) for that 1 millisecond, but it blew the tranny to bits. Lucky for my eyes and ears it was in a "sealed" diecast box.
From now on I'll ALWAYS use a fuse.
cheers
Perhaps it is a rite of passage in electronics that each one of us must test the necessity of a current limiting resistor at least once...
i can actually go one better than this lol. last term at school i was about mid way through my electronics coursework (building a guitar amp with tone sontrols, was designed to get me the marks not to sound good) and i connected one of the electrolytic filter caps between + 18 and - 18 volts.
problem was it was only rated at 16 volts. i was just retracting my arm from turning the power on when it blew up and fired the metal casing into the underside of my arm leaving a nice little pea sized lump lol. i still got %100 in the coursework so its all good tho :D
When I first started building kits and such about 15 years ago I build a midi interface for my PC ... but somehow I lost one of the current limiting resistors - I think it was about 330 ohms - and by my way of thinking then 330 ohms was quite a small resistance, so surely 0 ohms wasn't too far off? So I made a direct connection, plugged the interface into my PC's soundcard .... smoke escaped from the back, my PC rebooted, and I panicked! 8) The only permanent damage was to the joystick interface on the soundcard, but it DID make me work out what I had done wrong. Could have been a very expensive lesson! :)
Mike
I heard of one way to test caps...reliable source.
These amp builder guys were taking large caps, and charging them up with different voltages, then throwing them into a tub of water, and taking notes on the results. I think I'd start with a large tub, so I could stand back while throwing, and use goggles and rubber gloves.
Wow reminds me of my origninal Tube amp design. 280V B+ and it shorted inside the tube my tube blew, and a small piece(don't know why it didn't just explode)of glass thats olmost perfectly circlular just shot off(like chunk thats like radius of 4mm) and blew through the 1.8 mm aluminum casing of my amp. I now use circuit breakers for everything. Plus I killed the fuses in my house (only upstairs) and my mom lost all her work on the computer :oops: