Does blowing them up on purpose in school count? We learned "by example" in school what happens when you got it backwards...before one does it after you graduate...nope never have since 1984, when I "learned".
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Rick...
Back in the 70's I worked building TV studios and mixing consoles never provided phantom power back then, we added it on the patch field, two resistors and a 47uf capacitor. I could never remember which way round the 48 volts was meant to go. Gave the wireman instructions to terminate about 40 mic points and started testing. Throughout the following week I could hear these gunshot sounds but no idea where they were coming from. One afternoon I was leaning on the patch bay and 'bang' I had my answer. Never understood why they didn't all go off in salvo in day one but there was a hell of a mess to clear up.
Did that to my small dog. There was a power strip on the floor. There may have been kibble behind it, she was checking. BANG! Dog-tag crossed something. I was unable to repeat the event by hand but the burn-marks on the copper dog tag told the story.
I was lucky. My first was a PA setup. The amp sounded really good! 10 minutes later BWOOM!!!! Mushroom cloud. I asked if the power in the room was good, and the woman in the next office said her coffee-pot was hardly warm. Burnt-off Neutral at the box, low-bid contracting strikes again. Anyway the "117V" on my side of the wall was over 170V (like 64V in the next office). The soup-can sized e-Cap had puked a quart of paper-pulp inside the mixer/amp.
About 30 years ago, when I was 15 years old, I was working on a small amplifier with 2N3055 and a single power supply of about 40-50V, I accidentally reversed the polarity of a small ROE 47u/63V, the explosion was instantaneous after switching on, mother and father immediately ran from the living room to my room to see what happened, the room was a bit smokey and the aluminum can flew into the ceiling and returned to the table like a pancake. That was the first and last time🙂
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I built up a simple valve pre amp.
It didnt work so I turned it off and touched the circuit.
I off course got a shock from it.
My tutor said to discharge main cap before working on it.
So powered it up again and still not working.
So discharged the main cap.
Touched circuit and again got a belt.
Forgot to turn it off !
That was 40 years ago
Amazingly I have got to 65 without serious injury.
It didnt work so I turned it off and touched the circuit.
I off course got a shock from it.
My tutor said to discharge main cap before working on it.
So powered it up again and still not working.
So discharged the main cap.
Touched circuit and again got a belt.
Forgot to turn it off !
That was 40 years ago
Amazingly I have got to 65 without serious injury.
I blew up a smallish Panasonic HFQ part by inserting it backwards - it stank so bad I had to toss it in the dumpster outside. It smelled kinda like rancid burning Parmesan cheese...
55 years ago I convinced a neon sign company to sell me a 400w 10kv power transformer for my gas laser.
And I'm still here!
😎
And I'm still here!
😎
I’ve seen decommissioned pole pigs for sale on E-bay. Attractive prices if you can arrange local pick up, prohibitively expensive to ship. Even at 1/5 kVA rating when run dry, you could still build one hell of an amplifier, laser, or Tesla coil. Did Tubelab George ever buy one?
Biggest NST I have is about 200W. Got it from Skycraft many many years ago. It’s done it’s share of ‘experiments’ over the years - never anything serious, and nobody’s been hurt.
Biggest NST I have is about 200W. Got it from Skycraft many many years ago. It’s done it’s share of ‘experiments’ over the years - never anything serious, and nobody’s been hurt.
As part of my Mr. Fixit duties I maintained several gas "scribe and break" lasers, and a few Yag "laser trim" lasers in a microelectronics build operation. The scribe and break lasers were used to scribe a dotted line across the face of a large ceramic substrate so that it could be broken out into individual modules. We did 25 mill and 30 mill substrates with 50 and 100 watt CO2 lasers made by Photon Sources in the 1970's. When the new 800 MHz radios appeared in the early 80's there was a need for 40 mill substrates, so the 50 watt laser was scrapped and a 200 watt laser was purchased. The two large vacuum tubes in the 50 watt laser wound up in a monster radio transmitter that I built.
As radio production ramped up a single 200 watt laser could not keep up with the demand, so the boss asked me to apply a little "Tubelab" engineering to the 100 watt model. This monster had a power supply RATED for 25 KV at 500 mA. Two people had already been hit by its output and one had to be resuscitated by defibrillation. You don't "play" with that stuff. Examination of the schematics revealed that the power supply used a "saturable core reactor" in series with the file cabinet sized power transformer. The reactor used a variable DC current to partially saturate the core in an inductor to vary its inductance which controlled the output current from the power transformer. I simply bypassed the reactor which let the power supply run open loop. The voltage meter only went to 30 KV and it stayed pegged for two years. The pair of $1000 water cooled plasma tubes where the laser beam was generated used to last about 6 months. After my "tune up" this dropped to about 6 weeks, but this was acceptable to management.
Unfortunately, this operation unofficially made me the lead tech for this particular laser. I was smart and careful enough to avoid any injury, and several clandestine experiments resulted from my access to the machine. Attempting to erase a ceramic DIP 2716 Eprom with 200 watts of IR laser power will turn it back to sand leaving only dust and some of the gold plated pins. Someone used a front surface beam bending mirror in a pair of Vise Grips to burn his name in the ceiling tiles. Nobody claimed responsibility for that incident, and I was not present. There were two possible Garys with access to the laser, and neither admitted to doing it, but only one of them was crazy enough to do that. Lets just say that was not the beginning or the end of his adventures, or ours.
As radio production ramped up a single 200 watt laser could not keep up with the demand, so the boss asked me to apply a little "Tubelab" engineering to the 100 watt model. This monster had a power supply RATED for 25 KV at 500 mA. Two people had already been hit by its output and one had to be resuscitated by defibrillation. You don't "play" with that stuff. Examination of the schematics revealed that the power supply used a "saturable core reactor" in series with the file cabinet sized power transformer. The reactor used a variable DC current to partially saturate the core in an inductor to vary its inductance which controlled the output current from the power transformer. I simply bypassed the reactor which let the power supply run open loop. The voltage meter only went to 30 KV and it stayed pegged for two years. The pair of $1000 water cooled plasma tubes where the laser beam was generated used to last about 6 months. After my "tune up" this dropped to about 6 weeks, but this was acceptable to management.
Unfortunately, this operation unofficially made me the lead tech for this particular laser. I was smart and careful enough to avoid any injury, and several clandestine experiments resulted from my access to the machine. Attempting to erase a ceramic DIP 2716 Eprom with 200 watts of IR laser power will turn it back to sand leaving only dust and some of the gold plated pins. Someone used a front surface beam bending mirror in a pair of Vise Grips to burn his name in the ceiling tiles. Nobody claimed responsibility for that incident, and I was not present. There were two possible Garys with access to the laser, and neither admitted to doing it, but only one of them was crazy enough to do that. Lets just say that was not the beginning or the end of his adventures, or ours.
After Hurricane Wilma hit out neighborhood in 2005 pole transformers were lying in the street. They were just a little to heavy to bring home on a bicycle and the roads were impassable, so I never got one. That's probably a good thing. I saw some YouTube videos years ago where an idiot powered a reverse wired pole transformer with a gasoline generator and made huge fireballs. YT took down the video after a few weeks.
The biggest transformer I have is this one, but it hasn't seen power in about 15 years. I was going to use it in an 833A amp, but that amp will never be built.
Anyone want this transformer, a custom Transcendar OPT and some 833A tubes? Shipping would suck though.
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I had assembled a headphone amplifier board and was testing it and listening to it. I had installed one electrolytic backwards on the board. I noticed that the amplifier started distorting about 40 minutes after powering it up. I looked at the board and the capacitor was bulging, leaking, and started to smoke. It made a stinky mess.
Many decades ago, I opened up a piece of malfunctioning equipment (don't remember what it was) and was mystified by what I saw. It looked like a bunch of confetti and metal foil ribbons everywhere. It took me a minute to realize that a capacitor had escaped out of the top of its can. I was amazed how much foil there was inside that small capacitor.
Many decades ago, I opened up a piece of malfunctioning equipment (don't remember what it was) and was mystified by what I saw. It looked like a bunch of confetti and metal foil ribbons everywhere. It took me a minute to realize that a capacitor had escaped out of the top of its can. I was amazed how much foil there was inside that small capacitor.
Once I had a 1uF capacitor blown @ 5000 VDC. I had it attached with clips parallel to the 2 main capacitors of 10uF each. This power supply could deliver up to 1A DC current.
This was a remote supply in a separate building, using RG213 coax to feed my DIY hamradio amplifier and with a motor controlled variac.
I didn’t hear or see the explosion, but the capacitor was in pieces and I never found back the wire between the clips. Only the clips survived, but were black and heavily burnt.
No further damage! I could still use the power supply asif nothing had happened.
Oh, those good old days 😎
Regards, Gerrit
This was a remote supply in a separate building, using RG213 coax to feed my DIY hamradio amplifier and with a motor controlled variac.
I didn’t hear or see the explosion, but the capacitor was in pieces and I never found back the wire between the clips. Only the clips survived, but were black and heavily burnt.
No further damage! I could still use the power supply asif nothing had happened.
Oh, those good old days 😎
Regards, Gerrit
Best I ever did was use a .5A 250 volt glass fuse to fuse the 750V plate supply an on 811a amp.
Accidentally shorted a plate cap to the case and blew the fuse. Or I guess the fuse blew. I looked for it on the fuse holder and did not see it. Noticed one cap was still in the holder. Noticed the other cap in the bottom surface. Also a fine glass powder that I guess was the fuse body. Maybe use correct voltage ratings for fuses, not just current.
Accidentally shorted a plate cap to the case and blew the fuse. Or I guess the fuse blew. I looked for it on the fuse holder and did not see it. Noticed one cap was still in the holder. Noticed the other cap in the bottom surface. Also a fine glass powder that I guess was the fuse body. Maybe use correct voltage ratings for fuses, not just current.
Having had glass fuses explode on residential mains I'm a strong advocate of ceramic fuses on any application!
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