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viking said:
Things your young children experiment with, my son, when he was pre-teen used a nail or a paperclip and learned a valuable lesson.
I've been shocked so many times over the years that I almost got used to it, except for the time I had a transmitter chassis on it's side gripping it with my right hand and adjusting a potentiometer with my left hand when my thumb touched the top of a filter condenser, 750 VDC @ 1/4 amp. I look back at those times and wonder how I even made it to 78 years, that voltage with that amount of current can kill, I still have a faint scar on my thumb that reminds me what I went through so many years ago.
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That was tube based?

Ben
 
This all sounds like bragging rights for who took the worst shock, but I'll tell you of one power supply I never messed with. Back in about 1958-59 I went to a Navy surplus salvage yard in Bremerton, Washington, they had a very large tranformer that weighed around 200 pounds, filter capacitors and a large filter choke and all they wanted was $14, I took it home and built a power supply for transmitter that I never did build, but I experimented with the power supply trying to make a modified Tesla coil, it would light up a 4 foot fluorescent tube without touching a wire. I had deep respect for that power supply as it would put out 1,400 VDC @ 1.25 amps, the rectifier tubes were 4 mercury vapor types, I always suspected that the transformer came from a sonar power supply, I would have liked to have seen those parts as well but I imagine they were considered secret.
 
Most all of electronic hobbies were tube based, transistors were just becoming available, I built some things with CK722 transistors, even built a metal detector using the antenna coil out of a tube radio, actually worked pretty good, on the other hand I went through a lot of expensive transistors trying to build a powerful amplifier, stopped doing that after going through about $50 dollars worth, in those days I could never get the right transistors, the substitutes just didn't work. I really miss the tube era, 5U4's, 12AX7, 12BE7, 12AU7, 6SN7 and 6L6's and others. Sorry I don't have photos, that's only in my mind.
 
viking said:
Most all of electronic hobbies were tube based, transistors were just becoming available, I built some things with CK722 transistors, even built a metal detector using the antenna coil out of a tube radio, actually worked pretty good, on the other hand I went through a lot of expensive transistors trying to build a powerful amplifier, stopped doing that after going through about $50 dollars worth, in those days I could never get the right transistors, the substitutes just didn't work. I really miss the tube era, 5U4's, 12AX7, 12BE7, 12AU7, 6SN7 and 6L6's and others. Sorry I don't have photos, that's only in my mind.
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Was the 12AU7 a pentode?

I was weaned on vacuum tubes and stayed current until last year when I retired.

I ran out to the shop to take some pictures of some stuff you may enjoy.

Power diodes to the right and photomultiplier tubes to the left.

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High voltage transformers to the left variac to the right

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Mercury switch based pressure cobtrol assembly. Four switches for hi-hi, hi, lo, and lo-lo

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High voltage cap and resistors

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Front panel of a pdp 11/70

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Ben
 

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Well since the discussion was going to a shocking experience, here's mine.
I was just out of electronic school and got a job at a TV shop. We worked on a lot of stuff, TV, VCR, Radio/stereo, even at the start of CD players, also microwaves. About 2-3 weeks in one of the techs, up in his 60's and had been in electronics since he was a teen, was gonna show me some stuff with a big commercial microwave, anyway I somehow got a screwdriver across the magnatron nd BAM. Next thing I knew I was sitting up against the work bench behind me. Boss came running to the shop asking what happened. Tech told him. Boss said all he heard was OMPF after the pop. Kocked be a good 6 feet and off my feet. We laughed about that till I changed jobs. But I NEVER did that again.
 
backlash said:
When my Mom gave her doctor a bad time I always asked the doc if he knew who Granny Clampit was. That was my Mom. She was from the hills of Arkansas and she thought city doctors didn't know squat.
She treated all doctors as incompetent and dangerous.
She had lung cancer and had part of her lung removed but she claimed what actually cured her was her homemade salve.
She was even built like Granny.
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I kinda tend to agree with your mom, but then like my freind who just passed from lung cancer took a drug for past 20 years for stomach cancer which went to her lungs. Seems like it was Tamaflu. I just know it was a once a day pill.
 
Supervisor42 said:
You do things like that if you have ever danced with 3-phase 480v.
You never get hit with 480v because you are grounded.
But any leg to ground is 277v. :oops:
277v will leave a lifelong impression. And have you saying: "Aw hailno! never again!"
wye-600x410.png

For 3-phase 208, the worst you get to ground is 120v, not that bad:rolleyes::
3_phase_4_wire_wye.png

Sorry, I needed to post a pic.
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That stuff will make your teeth taste funny!
 
Did somebody say capacitors? :D
I found a bunch of fat ones in the junkyard. Got 'em for 20¢ per pound.
Put 2 of 'em to work cutting grass.
2 - 3500uf 100vdc caps almost doubled the power of my puny electric lawnmower.
Mowed the lawn with it for over 5 years and it was still running when I left it in the garage of the house when I sold it.
How it worked: AC power---long cord---full-wave rectifier---pulsed DC voltage---motor, I had the useless deadman handle switch connect the caps in after the rectifier and it had solid DC voltage then.
Presto TURBO!


(The motor had to be running before the caps were put in circuit or it would appear as a dead short when powered up)
 
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I put my finger on a capacitor buss bar on a portable xray machine and got hit with a lot of DC. Not sure how much but I never want to do that again.
A guy in our shop got 5000v DC across his gut. It picked him up and threw him over a workbench. We did cpr till the corpsmen got there. He lived but it was close.
 
Peanut said:
View attachment 60816
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Very nice.

From a view point of managing trees I first want to ask if that is two trunks of the same tree?

It looks like two opposing branches were cut off but left too much of the branches allowing both to grow agianst each other.

Looks like the right hand trunk is ailing. I suspect that image is transitory in that it will fall away.

Nice image.

Ben
 
Bacpacker said:
Ah come on Terri. Got have a little charge in your life!!!
Sounds many of us have made a living working with electricity in some manner.
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I didn't work with tubes very much before graduating to power transistors, then to SCR's, then to IGBT's, then to FETs, then to MOSFETs.
For us it was all about amps.
Amps=horsepower, and with horsepower, you can make amazing things happen.
If it can't handle 150 amps, it was a discrete in our book. :rolleyes:
I can post pictures of big semiconductors we used that can swing the big 'hammer' if anyone is interested.
Been busy the last 3 years trying to forget about them since I retired. (I'd have to fire up the PC).
It is amazing that so many great minds just happen to gravitate to this same place.
Thinking.gif

You think they miss us yet?
 
Supervisor42 said:
I didn't work with tubes very much before graduating to power transistors, then to SCR's, then to IGBT's, then to FETs, then to MOSFETs.
For us it was all about amps.
Amps=horsepower, and with horsepower, you can make amazing things happen.
If it can't handle 150 amps, it was a discrete in our book. :rolleyes:
I can post pictures of big semiconductors we used that can swing the big 'hammer' if anyone is interested.
Been busy the last 3 years trying to forget about them since I retired. (I'd have to fire up the PC).
It is amazing that so many great minds just happen to gravitate to this same place.View attachment 60823
You think they miss us yet?
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Management no. They never had an idea what we did. Those that that had to pick up the slack yes. I get a phone call every other month from the guy with the most experience.

Ben
 
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