What a silly comment for an ostrich. I note you didn't find all the other errors in his presentation either.
Some people have the strength to review presentations like this and be able to correct errors. You clearly cannot. A good man knows his limitations, you're a good man, er...ostrich..
I guess I'll have to find my errata sheet for that entire presentation and post it yet again.....
Speedskater, would you happen to have a copy of that?
edit: aha, finally got the search thingy to work, here it is:
Errata on Bills presentation
And the bad comment on slide 84 is what? Details..
jn
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Can't remember back when I read the Jensen papers and made my first audio dummies. Do wish I had them back in 73. They would have helped.
Slide 129, we had an almost identical poster on the wall back in Unit test, circa ;75. How bad are our schools that Bill has to present this anew! Of course, in the politically incorrect days, we told you what to grab with that hand. When working on TV's you learn to have your elbow on the arm with the screw driver touching the chassis. That way you only fry your arm. ( the human body has enough capacitance that the 27KV from a tube will kill you even if you are totally isolated.
Slide 132. Again and again. They would do it correctly except the weight of an adapter in the RCA source end would break off.
Needs to update slide 176. I wonder if Jensen is working on solving some of the HDMI issues. Ah, slide 186 Bravo! Heading over to their site now. I had a big problem last year with ground loops over HDMI. Bad auto-switch design was the culprit. Monoprice switch solved the issue.
Slide 189. Yea we have constant battles between the coms and IT folks. Coms guys insist of full ground planes with rods. We just use fiber and bypass the problem all together, but the won't change our specs!
Slide 129, we had an almost identical poster on the wall back in Unit test, circa ;75. How bad are our schools that Bill has to present this anew! Of course, in the politically incorrect days, we told you what to grab with that hand. When working on TV's you learn to have your elbow on the arm with the screw driver touching the chassis. That way you only fry your arm. ( the human body has enough capacitance that the 27KV from a tube will kill you even if you are totally isolated.
Slide 132. Again and again. They would do it correctly except the weight of an adapter in the RCA source end would break off.
Needs to update slide 176. I wonder if Jensen is working on solving some of the HDMI issues. Ah, slide 186 Bravo! Heading over to their site now. I had a big problem last year with ground loops over HDMI. Bad auto-switch design was the culprit. Monoprice switch solved the issue.
Slide 189. Yea we have constant battles between the coms and IT folks. Coms guys insist of full ground planes with rods. We just use fiber and bypass the problem all together, but the won't change our specs!
Andrew, Well in NYC I guess they have an advantage as their code still favors conduit. Rat proof too. Yes, I was referring to the referenced Jensen paper. Question, on your side of the world, is the 220 two phase with safety or 220 and neutral? Seems how you address some of the issues may differ a little.
Hmm..
E = 1/2 CV2
The standard ESD model for the human body is 1000 picofarads, 1000 times 10-12.
So, the total energy in joules for charging the 1000pf human body is:
1/2 * 1000 * 10-12 * 272 * 10+3 * 10+3
E = 500 * 729 * 10+6) / 10+12
E = 364500 *10-6)
E = .364 joules.
Oddly, current safety practices list 10 joules as the lethal threshold, and only if applied in the most unlucky situations. Where did that bad assumption come from?
Other than that, I do tend to agree with you, our schools do need updating on some concepts. E/M theory certainly being one of them. I find so many engineers don't understand it.
jn
You just might get more respect around here if you didn't name call and insult. I respect your knowledge but not your manner of getting it across. Do you not get out in the real world often and interact with people face to face?
Ah, wasn't sure who you were talking to earlier. Go back and re-read this thread, as you seem to need a refresher.
edit: I just LOVE how you say that here, and then a minute or so later, you tell JC indirectly that his good friend Jack Bybee is a scam artist. Hmmmm.
Start here:
Where were your comments then?
jn
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I think you need a dictionary JN. The quote you posted from TVRgeek is in no way insulting to anyone at all. Your statements on the other hand are very much so. Even if someone was insulting yourself then you feel like it's right for you to act like a child also?
Also you need to improve your reading comprehension. TVRgeek already said you were blocked so why would he respond?
Also you need to improve your reading comprehension. TVRgeek already said you were blocked so why would he respond?
Hmmm, Still get an e-mail as I was not watching some posts.
When I went through certification at Radius, they made a very big point about the lethality of a color tube. I wonder, were the standards made when we were nice healthy 135 Lbs, not the typical American slob of 250 and up today? The threshold of through chest current being 135 ma. as we were instructed. A few things like that one never forgets. Standards don't keep up, or over cautious and inaccurate?
When I went through certification at Radius, they made a very big point about the lethality of a color tube. I wonder, were the standards made when we were nice healthy 135 Lbs, not the typical American slob of 250 and up today? The threshold of through chest current being 135 ma. as we were instructed. A few things like that one never forgets. Standards don't keep up, or over cautious and inaccurate?
The UK domestic supply is usually a nominal 240Vac, using Live, Neutral and Protective Earth.
All socket outlets are to BS1363, which are polarised to prevent L& N swapping and have shuttered L & N to prevent children inserting fingers and tools inside.
The BS1363 Plug tops have three rectangular pins. The long Earth Pin opens the shutters to allow the Live and Neutral to enter and make contact.
The plug top has a replaceable BS1362 fuse inside.
There are some "special" use sockets that are not to BS 1363.
We diyers are no longer allowed to do any DIY on the supply installation. Either the work must be approved in advance or an approved electrician must be employed to add to, or modify the installation.
Europe is all over the place. nominally 220Vac but no universal socket outlets.
All socket outlets are to BS1363, which are polarised to prevent L& N swapping and have shuttered L & N to prevent children inserting fingers and tools inside.
The BS1363 Plug tops have three rectangular pins. The long Earth Pin opens the shutters to allow the Live and Neutral to enter and make contact.
The plug top has a replaceable BS1362 fuse inside.
There are some "special" use sockets that are not to BS 1363.
We diyers are no longer allowed to do any DIY on the supply installation. Either the work must be approved in advance or an approved electrician must be employed to add to, or modify the installation.
Europe is all over the place. nominally 220Vac but no universal socket outlets.
I have to laugh when they change the lethal levels. First, it was 2 milliamps, then it suddenly went up to 10 mA (AC)... What are they doing, testing human subjects???
Did you say 135 milliamps?? I'd wager to say that that MOST CERTAINLY would be lethal. At the moment, the standards are 10 mA AC, and 60 mA dc, with 10 joules of instantaneous stored energy.
And I'm sure those will change eventually..
Do you remember if that 135 mA was AC, DC, or RF?
jn
Ah, thanks. 27kV, I remember color tubes at 17kV levels back in '74, I suspect the phosphors kept getting better. Now, when I give lectures and tours, the kids don't even know what a color television tube is. We are getting old..
Any mention of X-rays at that level, especially the rectifier?
jn
By then the HV was SS, so the x-rays were addressed by all the lead in the tube. Mostly.
I wonder as I am approaching cataract surgery time, all the hours I spent with my head in a scope hood, did that have any effect on my eyes? Besides the refresh rate and not hearing the squeal of the fly-back, I am most glad to stare at an LCD/Florescent display all day now.
They don't know why we "dial a phone" and really really scary, A coworker was giving a group of students a tour at a college and pointed to the clock tower. One of the tour admitted they could not read an analog clock. Guess a freshman class would not know what a slip-stick is. "Not in the standard core" will be the cry of the next generation.
I wonder as I am approaching cataract surgery time, all the hours I spent with my head in a scope hood, did that have any effect on my eyes? Besides the refresh rate and not hearing the squeal of the fly-back, I am most glad to stare at an LCD/Florescent display all day now.
They don't know why we "dial a phone" and really really scary, A coworker was giving a group of students a tour at a college and pointed to the clock tower. One of the tour admitted they could not read an analog clock. Guess a freshman class would not know what a slip-stick is. "Not in the standard core" will be the cry of the next generation.
I recall on this side of the pond, the homeowner is allowed to modify without approval or inspection. To me, very scary. Some of the "handyman" work in my own house defies belief. I even use pictures of the work in my "what to look out for" section of the talk.
When I do major wiring, I'll call in the inspector even though I have NEC2008 in hand. Never can be too safe with family.
When you say supply, are you speaking of branch circuits, or service entrance? Me, I won't touch the service entrance stuff, that scares me.
jn
Back in the day, it was the HV rectifier tube that was supposed to be the most energetic source. I really don't understand why though, as 27Kev electrons are the same regardless of where they are. Perhaps the phosphors absorbed more by design, instead of giving off Bremsstrahlung as they hit the rectifier plate.
Who knows?? Might just be age or genetics. I'm on the lookout as well, blue eyes. Scope hood? as in old style phosphors, low rep rate, dark room scope viewing? Same here, 1 KHz rep rate analog, 250 pS risetime waves..
jn
I thought most of the X-rays came from the EHT stabiliser valve? The rectifier has a much smaller voltage across when it is conducting, and it doesn't matter when it is reverse biased. The CRT will produce X-rays from the shadowmask but will these mostly go backwards away from the viewer? I don't know about the glass and phosphor - perhaps you need a metal target to get a lot of X-rays?
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