Thanks for pointing this out. You see, that's the beauty of "solid state" electronics: the old tube circuits needed much bigger components, since the tubes were made of glass, and couldn't withstand much internal smoke pressure (I think that they were barely above atmospheric pressure, actually). With the advance of polymer chemistry came the development of transistors, and then later integrated circuits; as we all know, the cases of these modern components are made of polymers, which are much stronger and can withstand extremely high internal "smoke pressures". Hence, a lot of smoke is packed in there under extremely high pressure. Therefore, when you let it escape, it expands to fill a very large volume. Note: Electrolytic capacitors are carry overs from the old technology: although their metal cases are stronger than glass, they still tend to leak smoke much more easily than transistors and ICs. Hence, the more of these that you have in a circuit, the more the chance that the circuit's "essential smoke" will leak out.
Sometimes the smoke in an electrolytic capacitor comes out in a concentrated gooey state, often preceded by a loud bang. Did you ever put tantalum capacitors in a power strip? That makes a great noise. Turn off the power strip, shove a small tantalum cap into one of the power sockets, and wait for some poor sucker to turn the strip back on: BANG!, and a puff of smoke. Tom
Thanks, Tom. What a great idea about the capacitor. I've never tried that. I've used another approach: wait until someone has just finished servicing some high voltage device. As they turn it on, secretly pop one or more bubbles on a section of "bubble wrap". The big bubbles snap louder. The small bubbles can be snapped very quickly in succession, making a sound like rapidfire mutliple arcs. Stepping on them works great for this approach.
That's very nasty. The guys used to like to smack a yardstick down on the table behind me when I had my hand inside of HV gear. They liked to watch me jump. Tom
This crosses the line into horseplay. Having grown up in an environment with lots of power tools, heavy machinery, and firearms, and where horseplay was considered a serious character defect, and a major cause of serious injury among teenage males, I have zero tolerance for horseplay in the workplace.
Another one that may cross into the realm of horseplay is to take a high voltage capacitor, charge it up, and toss it across the room to someone while yelling "Here, catch." They won't catch it a second time. Tom
Thank you for that link, Steve. That was perfect! See, I never even knew that it had an official name: "magic smoke". I'd only found out about the magic smoke within the last couple of years. So I'm just a novice when it comes to "smoke theory".
On a serious note, I totally agree. I never, ever startle anyone who is ever in any type of potentially dangerous situation. I'm especially careful when approaching anyone working around power equipment or electronics, who may not hear me coming. I know that when I'm using my shop tools, I can be startled quite easily if someone comes into the shop unexpectedly because I cannot hear them approaching.
I pulled a similar stunt on a terrified student by using a large diode. As you're aware, depending on how you bias the diode, it will easily block the voltage. I stuck the diode in the lab power port - properly biased of course - and with our safety glasses on, I flipped the switch. My lab partner flinched and ducked under the table as ... nothing happened So I turned the bench power switch off, and flipped around the diode. I then ducked under the bench with my terrified lab partner, reached up for the switch, and .... CRACK!!! The leads were still in the receptacle. Everything else had made an instant transition to Smoke. Funnily enough, my lab partner spoke with the prof, he got a different lab partner, and I was assigned a cute perky redhead with a chest to die for, which had been my sinister plan all along ... Did I mention we got the highest lab grades? Probably because we spent so much time together, in many different positions urgh hurhum I mean locales
I'm sure if the HV equipment was "live" the entire room of engineers would have been deadly serious. But with all routine safety precautions, expect engineers to act like a bunch of 10 year olds: after half an hour, even farting noises become the norm! And to that guy at the radar site we scared the hell out of, we sure did appreciate you didn't grab a 16 and start shooting at us. And we sincerely hope that we didn't give you a brain tumor from all that energy we pumped into the air ....
I am an engineer. But the rural environment full of farm machinery, logging equipment, and firearms came first. Unfortunately, not all Darwin Awards are caught by the person with the 'winning' genes. In a quarter century, only one officemate was a serious prankster, having been raised and educated in a completely different (and much less hazardous) environment on the opposite coast. At first he didn't understand my objections. But after pulling a stunt intended to put me in momentary fear of an assault, in a region where lethal force is a legal option to stop violent assaults, I responded ... "don't ever do that to a gun owner." Suddenly he understood. His other horseplay also ceased. He was one of numerous acquaintences who came from backgrounds opposing civilian gun ownership, yet simultaneously enjoying pranks putting people in momentary fear of injury or assault. But he was a fast learner.
We wouldn't get on at all at work. One of my work mates is still wondering who put all the pages in his legislation manual up side down.
A funny little story from the Apollo space program: For the moon walks, the astronauts had checklists on wrist bands which clearly spelled out each task. Before the launch of Apollo 11, the guys on the ground "edited" the checklists and added some photos of naked women. So here you have Neil and Buzz, with all of the world listening, and the ground controller tells them to turn to step whatever, and what do they find staring back at them but a photo of a naked woman. The conversation went something like "Roger...ah...I like the looks of that procedure." Tom
Yes, in that environment, safety comes first But in a boring lab environment, it's healthy to blow off a little steam. You'd be surprised how all that tomfoolery - Tom are you listening? - actually contributes to a much better working environment, and even some genuine breakthroughs And despite whacky fun in the lab, all the engineers I personally know are deadly serious around firearms, tanks, field artillery, tractors, and chainsaws Actually, the Geneva Convention should make it illegal for a left handed person to even *touch* a chainsaw. I once watched a lefty try to operate a chainsaw, it was scary. Made me appreciate having "normal" dominant hand assignment
Something tells me if we were in the same shop, our exploits would become legendary, and we'd always be keeping each other on our toes
