Author Topic: Seems logical to ME!!  (Read 9018 times)

Govmnt_Lacky

Seems logical to ME!!
« on: September 18, 2010, 02:57:58 PM »
I have read SEVERAL topics on this forum regarding the buildup of vacuum tube-based projects. (a-la 12AX7, 12AU7, etc.) In ALL of them there is at least one mention of "knowing what you are doing since there are HIGH VOLTAGES present."
Instead of putting out the 300th warning, how about we put up a HIGH VOLTAGE thread to inform the DIYers out there instead of just warning them. ???

I work with high voltage electricity everyday however, I am not an expert regarding the field of vacuum tubes, effects voltages, etc.

I would expect that there are many, many people on here that could provide valuable information regarding this.

Why can't we help newer builders (including me regarding this type of build...so I am biased) on this matter insead of just warning them all the time. Seems logical to me... ::)
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for an amount of ‘up to and including my life.’

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Re: Seems logical to ME!!
« Reply #1 on: September 18, 2010, 03:35:19 PM »
I have produced a few projects on this forum for regular, low voltage effects. Most people know what they're doing for the most part, but sometimes I get emails from people who have done something so hopelessly wrong that I'm kind of schocked. I have seen someone who connected all of their offboard parts with bare copper wire - no insulation - with the wires all tangled up in a random mess and touching various areas of the board. In other words, shorting everything to everything else. I have seen people use plumbing solder which eats all the traces up. Etc.

Since these were low voltage effects, the only harm is that their effect doesn't work, or worst case, needs to be trashed and begun again. If these same people had done the same things with an amp, well, you know what sorts of things might happen. Of course, people are responsible for their own actions, but there are legal and moral issues that arise when you hand somebody a little bit of info, which sends them right towards their demise.

I think it's good to keep an aura of fear around working with high voltages. It will hopefully put off people who aren't interested in doing their homework. For people who don't mind reading a little bit, I don't think these warnings serve as too much of an annoyance.

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #2 on: September 18, 2010, 04:12:11 PM »
I think it's good to keep an aura of fear around working with high voltages. It will hopefully put off people who aren't interested in doing their homework. For people who don't mind reading a little bit, I don't think these warnings serve as too much of an annoyance.

It is not so much of an annoyance as it is a "holier than thou" decleration! I am in no way an expert in the effects building world however, I am also not totally ignorant when it comes to electronics, electricity, theory, etc.
My point is that if you could search this forum for high voltage tube based project warnings you would probably find dozens of them (and an enormous amount of them are condesending as well!) If you searched for "helpful" information regarding how to deal with these higher voltage effects projects, you would not find near that many!
People are people and when you say "keep an aura of fear," that is ALL IT WILL DO. People will still proceed with the project. I am merely suggesting that we use the common knowledge of this forum to ensure that they do it safely instead of taking the "I know what I am doing, too bad for you..." attitude.
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

phector2004

Re: Seems logical to ME!!
« Reply #3 on: September 18, 2010, 04:19:16 PM »
+1

I've spent countless hours reading up enough to know what's right and what's wrong, and although I'm no electrician, I've taken every single precaution possible to keep myself safe.
But there are others that are too lazy to read up on what to do, how it works, and how to do it properly.

Warnings won't keep people from doing something stupid. Information will help them do it right.

R.G.

Re: Seems logical to ME!!
« Reply #4 on: September 18, 2010, 04:27:09 PM »
I have read SEVERAL topics on this forum regarding the buildup of vacuum tube-based projects. (a-la 12AX7, 12AU7, etc.) In ALL of them there is at least one mention of "knowing what you are doing since there are HIGH VOLTAGES present."
Instead of putting out the 300th warning, how about we put up a HIGH VOLTAGE thread to inform the DIYers out there instead of just warning them. ???
...
Why can't we help newer builders (including me regarding this type of build...so I am biased) on this matter insead of just warning them all the time. Seems logical to me... ::)
Because I am not a lawyer, don't want to be one and in most situations don't even want to talk to them if I can help it.

Let's do a hypothetical situation. You and I write up a "Beginner's guide to working with high voltage safely" and publish it. Many thoughtful, responsible people read it and are happy, doing careful and responsible jobs of using the information. But Leroy, who is 17 going on 11, decides to build the most kick-ATZ high voltage amp/pedal in the world and misreads/ignores/forgets section 2, or does something where a section Z which we didn't write is needed. He is fried; or worse, brain damaged; or worse yet, completes the job, gives it to his innocent kid sister, who is electrocuted; or even worse, leaves it on overnight and the house burns, killing all but one of the family.

Surviving family sues. Not Leroy. But (1) the internet service provider (2) aron for hosting it (3) you and worst of all (4) me. The suit alleges we recklessly and with wanton disregard for the life and property of others not only allowed by negligence but encouraged Leroy to do Dangerous Things by convincing him that the info was not only true and accurate, but complete for all situations and worse yet easy - not even taking into account Leroy's well-known history of being both suggestible but not too bright to start with.

By US law any person or organization who was responsible in any way or portion, no matter how small, for loss or death is responsible for the entire amount of damage, plus multiplication of damages and legal fees if a majority (unanimous is not needed in civil cases) of the jury didn't like what they had for lunch. If you're 1% responsible and the jury had burritos, you're 100% financially responsible. And that doesn't even start to approach criminal negligence, which could be in the mix if you get a DA who's looking to make a political name for himself by criminal charges for "the internet".

This kind of thing carries too much risk to be posed in a forum. A whether a disclaimer applies or not again depends on what the jury had for lunch. Or are bored.

The correct advice is - if you want to do this kind of thing, GO GET IN-PERSON, HANDS-ON TRAINING WHERE A SKILLED PERSON CAN CHECK YOUR WORK. Things which carry the possibility of death, and delayed hidden death need responsible, direct training. You don't find any DIY surgery manuals very often, right?

Frankly I find it appalling that anyone would think that this is hidden knowledge designed to hold people back.
+1

I've spent countless hours reading up enough to know what's right and what's wrong, and although I'm no electrician, I've taken every single precaution possible to keep myself safe.
But there are others that are too lazy to read up on what to do, how it works, and how to do it properly.

Warnings won't keep people from doing something stupid. Information will help them do it right.
Correct - but "how to do it right" is to get trained in a way that someone already skilled can check your work for things you didn't know that you didn't know.
R.G.

Quick IQ Test: If anyone in a governmental position suspected that YOU had top-secret information on YOUR computer, how many minutes would you remain outside a jail cell?

phector2004

Re: Seems logical to ME!!
« Reply #5 on: September 18, 2010, 04:31:58 PM »
Dammit, Leroy!

Where could somebody get such training? (Aside from becoming an EE!)

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #6 on: September 18, 2010, 04:36:12 PM »
[Jumps onto soapbox..]

Part of this post is because I see too often that some (not all) of the forumites like to "rice-bowl" their knowledge in that they like to talk about how much they know but never really help people when they need it. I am really tired of seeing people post on here needing help and just attracting those few people that give them 7 paragraphs of needless information when they just needed to know that their IC is in backwards.
IMHO... if you want to hold out on your knowledge or, on the inverse of that, talk WAY ABOVE the poster's head then you should not be here in the first place! I take great pride, with my limited noob knowledge, in helping people on this forum because that is what I would expect in return! :icon_mad:
If you don't want to offer any REAL help then just DO NOT POST! Go to your ultra-intellectual pedal building area and insult your peers. People on here NEED HELP and are not as smart as you. They also DO NOT want to cater to your egos  :icon_mad:
If someone needs my help, then I help. I only ask in return that you be willing to help me or someone else the same way! Don't get me wrong, I WILL NOT do it ALL for you. I will however, help you in any way I can because that is what I expect out of this forum and what I would want in return!

[Jumps off of soapbox...]

If you find that you are insulted by that rant, then you are most likely part of the problem! If you find that you areindifferent to it, then you are just another forumite like me!
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #7 on: September 18, 2010, 04:41:59 PM »
Because I am not a lawyer, don't want to be one and in most situations don't even want to talk to them if I can help it.

Let's do a hypothetical situation. You and I write up a "Beginner's guide to working with high voltage safely" and publish it. Many thoughtful, responsible people read it and are happy, doing careful and responsible jobs of using the information. But Leroy, who is 17 going on 11, decides to build the most kick-ATZ high voltage amp/pedal in the world and misreads/ignores/forgets section 2, or does something where a section Z which we didn't write is needed. He is fried; or worse, brain damaged; or worse yet, completes the job, gives it to his innocent kid sister, who is electrocuted; or even worse, leaves it on overnight and the house burns, killing all but one of the family.

Surviving family sues. Not Leroy. But (1) the internet service provider (2) aron for hosting it (3) you and worst of all (4) me. The suit alleges we recklessly and with wanton disregard for the life and property of others not only allowed by negligence but encouraged Leroy to do Dangerous Things by convincing him that the info was not only true and accurate, but complete for all situations and worse yet easy - not even taking into account Leroy's well-known history of being both suggestible but not too bright to start with.

By US law any person or organization who was responsible in any way or portion, no matter how small, for loss or death is responsible for the entire amount of damage, plus multiplication of damages and legal fees if a majority (unanimous is not needed in civil cases) of the jury didn't like what they had for lunch. If you're 1% responsible and the jury had burritos, you're 100% financially responsible. And that doesn't even start to approach criminal negligence, which could be in the mix if you get a DA who's looking to make a political name for himself by criminal charges for "the internet".

This kind of thing carries too much risk to be posed in a forum. A whether a disclaimer applies or not again depends on what the jury had for lunch. Or are bored.

The correct advice is - if you want to do this kind of thing, GO GET IN-PERSON, HANDS-ON TRAINING WHERE A SKILLED PERSON CAN CHECK YOUR WORK. Things which carry the possibility of death, and delayed hidden death need responsible, direct training. You don't find any DIY surgery manuals very often, right?

Frankly I find it appalling that anyone would think that this is hidden knowledge designed to hold people back.

I guess we should just quit now and shut this bad boy down.

I am not a lawyer either however, I do know that even working with the voltages that are NOT involved with vacuum tube based builds can still injure or harm someone. Wall wart power can injure or KILL someone! Battery power can even do harm! So where do we go then?
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

Galego

Re: Seems logical to ME!!
« Reply #8 on: September 18, 2010, 06:46:22 PM »
I like the warnings, the more the better. When I built my amp there were a few on the kit instructions, and they did keep me on my toes, and I learned to be very careful and to replace the fear with attention and respect.

Quackzed

Re: Seems logical to ME!!
« Reply #9 on: September 18, 2010, 06:52:48 PM »
I think you get the idea that the danger of electrocution is quite small when dealing with a 9 volt battery, so most people will risk advising someone on 'messing about' with it  with no real fear of harm to the experimenter. in the end it's personal choice, if you feel it's too dangerous to help out with a fuzz build, you can refrain from doing so. but i think most people will agree that 'messing about' with wall voltages are much more likely to result in injury or harm. so naturally people are reluctant to encourge someone to 'try and see'.
i can understand being insulted by people who refuse to advise on certain percieved dangers, but in fairness ,sadly , the truth is that legally they may be held financially accountable. and if you consider how many people read and browse these pages, perhaps you can understand that there are lots of leroys out there, and that you shouldn't feel like that is a reflection of your own intellegence or personal responsibility
,it's rather that it needs to account for not endangering 'every' pair of eyes that reads it...

btw i don't mess with wall voltage. i've never built anything beyond 9volt batteries or equivalent wallwart 'juice'.
I hooked up a motor to a switch once for a leslie i found. but I had an electrician friend check it out for me before i plugged it in.
He said it was fine, but i still feel a bit nervous switching it fast/slow...  :-[
nothing says forever like a solid block of liquid nails!!!

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #10 on: September 18, 2010, 06:56:16 PM »
I like the warnings, the more the better. When I built my amp there were a few on the kit instructions, and they did keep me on my toes, and I learned to be very careful and to replace the fear with attention and respect.

I agree. The warnings are needed and vital however, you mentioned that they came with instructions. My position is that there are nothing but warnings! How about some instructions to go WITH all of those warnings?
This is a DIY site right? There are experts to guide you during your build... right? A shared database that has information AS WELL AS the warnings to go with it...right?
I know of a place where I can go to build custom effects with ABSOLUTELY NO support or help.....

Its called GOOGLE!
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #11 on: September 18, 2010, 07:01:56 PM »
I really am sorry to all of you forumites. It has been a VERY BAD DAY! I really do not mean to insult anyone as I have found this forum to be an invaluable resource for everyone. For the most part, people are very helpful here. As a matter of fact, I just sent out some parts to some forumites in hopes of building up a repore with these people as I know sometime in the future, I may need their help.
That is the way that I work. I will be willing to do whatever I can to help with my limited knowledge and resources. And in return, I expect the same from all of you.

This apology is to all.  :icon_redface: :icon_redface: :icon_redface:
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

ianmgull

Re: Seems logical to ME!!
« Reply #12 on: September 18, 2010, 07:27:00 PM »
You just have to realize that nobody here is willing to be personally responsable for what could go wrong. It's nothing personal or psuedo intellectual or whatever. It's a matter of personal liability plain and simple.

I started with stompboxes about 3 years ago. At the time I knew NOTHING. Just this summer I completed my first high voltage tube preamp. It took about 40hrs start to finish. Over half of that time (approx 23 hrs) was spent reading everything I could about the particular unit I was building (what could go wrong, what has gone wrong when others built it, how to tell if something has gone wrong). This all before I even touched a soldering iron.  In all I ended up learning quite a bit about working with high voltages. It fired up first try. I like to think that is because so much time was invested in the front end.

The point is if someone had simply printed a 5 page pdf document meant to be a "build guide" people (myself included) might not have been so inclined to spend a large amount of time doing their own research and thoroughly educating themselves. In the end this is what is needed. High voltages should be scary. That is a major reason why so much of this is not discussed. It is simply not the type of thing that can be summarized in a few pages with a few pics. It literally requires you to make a commitment to educating yourself through multiple sources.
« Last Edit: September 18, 2010, 07:30:34 PM by ianmgull »

PRR

Re: Seems logical to ME!!
« Reply #13 on: September 18, 2010, 10:15:00 PM »
The Safety thread at Hoffman forum is worth looking at.

I have many thoughts and NO answers.

> People will still proceed with the project.

I see a LOT of potential builders scared to touch anything over 9V. (Me, I grew up sticking thumbtacks in 110V cords, so I don't understand the fear.) (And I think TR wall-outlets are part of the dumbing-down of America.)

> the possibility of death

It's possible. I knew a guy died inside a Xerox machine. Lacky here and Buttery at Hoffman "work with high voltage electricity everyday" and probably know of some local electrocutions.

But how many people have been electrocuted in hobbyist audio (hi-fi or guitar)?

We'll never prove "none".

But the number is NOT high.

AFAICT, it is dang near zero.

Studies of electrocution show hairdryers and construction workers lead the home and work fields. You can die in McDonalds, plugging-in the fryer after the floor is mopped.

There's a website of dead musicians. True, musicians mostly don't open amps. And it is "famous" musicians, the 1%. Of course many of the deaths are what you expect: drugs, airplanes, etc. About 3 electrocutions, but one had nothing to do with being a musician (light over the bathtub).

IMHO, your risk is far higher driving to the store for milk. (Last night I was in the 1-ton Miata, a guy in a 3-ton truck was about to merge on top of me.)

Or playing-out in an over-crowded sub-Code room full of drunks.

What about other dangerous hobbies? Car-racing? Sure, the track makes you sign-off your life, and inspects your rollbar and seatbelt... but they don't go on and on about the danger. Last week local hobby-racer John died at the track. But not ON the track... he won his heat, shook a lot of hands, and keeled-over on his way to his truck. 57 years old; makes me think.

> Get In-Person, Hands-On Training Where A Skilled Person Can Check Your Work

A) How many people KNOW how to wire a line-entry? In my town, it was 3 but one died last winter.

B) Neighbor George thinks I know something about electronics. Say he sends his son over for a lesson. Would I remember ALL the rules for ALL situations? Could I teach them clearly? Can son retain a technical thought better than his dad (brilliant in many ways, but not a tech)? As for actually DOING his line-wiring... that's like work and carries risks, and last year I choose to reduce my work and risk-responsibility.

> Aside from becoming an EE!

I've seen grad-EE students wire a BBD. There's no way I'd let them try line-wiring.

I have an EE textbook which warns of dangers, but emphasizes that the book and the EE program in general does NOT qualify the student to do power wiring. (Strictly: actual wiring is "below an EE's pay-grade". That's a job for Technicians and Electricians.) A mature inquisitive EE may understand power wiring methods and practices and dangers, but that's not implied by the EE diploma. Your local Vo-Tech Practical Electronics may do more for you. Or not.



Treat electricity like a bucket of deadly snakes.

Don't EVER stick your hand in the box while snakes are in there.

Don't assume there are no snakes-- CHECK.

Use clip-leads so you can monitor voltages without having your hands anywhere near snakes (remember that this snake can crawl up wires).

Clamp your metal ANY time you drill. Drilling and sawing accidents may not be fatal but they are awful bloody and can be disabling.

GFIs are a Good Idea, both on the bench and at the club. Do NOT assume they will stop all loose snakes.

R.G.

Re: Seems logical to ME!!
« Reply #14 on: September 19, 2010, 12:07:01 AM »
> Aside from becoming an EE!
I've seen grad-EE students wire a BBD. There's no way I'd let them try line-wiring.
I spent decades among a couple of hundred EEs in a design facility. I know a total of four of them whose AC line wiring I'd trust without checking it myself.

Becoming an EE is specifically NOT a way to learn safe wiring. There is no time in the EE curriculum for learning safe AC wiring. Too much other theory needed; and frankly, sending an average EE off to do power wiring is a waste of both the EEs time and the equipment he'd wire.

Becoming a licensed electrician or HVAC technician is a lot closer for this particular specialty. The training for those specialties does include safe power wiring - if they haven't been dumbed down yet. Find an amateur radio operator that has built his own equipment (if you still can) and he'll know how to instruct you.

The legal morass is very much deeper than even I've alluded to. The standards institutes which write and publish the wiring safety specs do not say "do this and what you do is safe".  They say "if you don't do at least this much, it is not safe; doing more may be safe or not, we can't tell you, and in any event, you're legally responsible if you do this and more, but guess wrong." To add insult to injury, the very standards which describe the level where below this is known UNsafe are not free. You must buy them, at a couple of hundred bucks apiece, and the issuing standards institutes are legally aggressive at enforcing copyright. They aren't on line. Period. And they change the standards, so you really have to buy a subscription to stay current. And there are hundreds of safety standards, more than one of which may apply to any one piece of equipment.

I have peeked into a number of boutique tube amps' innards. In some cases it was bad enough that I literally did not want my fingerprints on the amp I was looking at. Knowing what a rattlesnake or cobra looks like can be sobering when you wander up on one in the wild.

European law used to offer presumptive safety and hence presumptive immunity to legal action. It was hard as blazes to get a certification from their national safety labs, but once you did, you were effectively immune to lawsuits because you had complied with the laws. No longer. They have adopted the USA model where there are safety guidelines/standards are a disqualification minimum, and anything less is deemed presumptively not safe. But there is no guarantee, and you are liable even if you have having complied and had an independent lab certify that you complied if any damage results. Anytime. Even if the user was 99% at fault and you were 1% at fault.

If you can't talk fluently about single versus double insulation, may-touch metal, ground bond currents, safe-touch temperatures, insulation temperature rise, creepage and clearance distances and many others, you should be very uneasy about doing your own AC power wiring. A possible alternative is having seen enough correct wiring to have a mental picture of what is good versus bad practice; literally, learning by experience. That's why I say - get a personal instructor to check your work.

I'm reminded of the joke about the entrance exam for a particularly tough medical school: "Test section 4: Surgery. You've been provided with a bottle of alcohol, razor blade, and needle and thread. Remove your own appendix. Do not suture until your work has been checked."  :icon_lol:

As PRR says, the number of people who have electrocuted themselves doing effects and even tube amps is quite small. I'm pretty sure it's not truly zero, but quite small. However, it only takes one. Stay safe. We need all the people making effects and music we can get.
« Last Edit: September 19, 2010, 12:09:39 AM by R.G. »
R.G.

Quick IQ Test: If anyone in a governmental position suspected that YOU had top-secret information on YOUR computer, how many minutes would you remain outside a jail cell?

Pigyboy

Re: Seems logical to ME!!
« Reply #15 on: September 19, 2010, 05:41:47 AM »
A side tangent:
A Frenchman whose limbs were blown off by a current surge removing a tv antenna swam the English Channel yesterday so all the Leroy's have something to look forward too.
 :icon_eek:
I cut my teeth in the High Voltage lab at General Dynamics and the one thing drilled in was the one hand rule. Always, always, always if there may be any chance of HV put one hand in your back pocket and inspect with the other to prevent current from passing thru the heart and auto-defibrillating yourself to oblivion. One hand in the pocket and not resting on the metal desk...
Myself and others are experimenting with switching mode power supplies here that generate 300v at maybe 100ma. I have yet to bite myself with this but he current is low enough that I think I will survive.
It is current that kills.
Beware of low voltages with high current.
Keep that bong and coffee cup far from your work area.
Learn Ohm's Law
Be very diligent and possibly join a tube amp forum such as AX84.
I have found a few old guys out there who grew up in the tube era and are willing to talk and share their knowledge such as Harry Lythall.
I will never forget David D. yelling at me across the lab, "One hand, one hand!"
And you'll have to admit, I'll be rich as shit
I'll just sit and grin, the money will roll right in....
                                                            - FANG

Govmnt_Lacky

Re: Seems logical to ME!!
« Reply #16 on: September 19, 2010, 07:55:26 AM »
A side tangent:
A Frenchman whose limbs were blown off by a current surge removing a tv antenna swam the English Channel yesterday so all the Leroy's have something to look forward too.
 :icon_eek:
I cut my teeth in the High Voltage lab at General Dynamics and the one thing drilled in was the one hand rule. Always, always, always if there may be any chance of HV put one hand in your back pocket and inspect with the other to prevent current from passing thru the heart and auto-defibrillating yourself to oblivion. One hand in the pocket and not resting on the metal desk...
Myself and others are experimenting with switching mode power supplies here that generate 300v at maybe 100ma. I have yet to bite myself with this but he current is low enough that I think I will survive.
It is current that kills.
Beware of low voltages with high current.
Keep that bong and coffee cup far from your work area.

Learn Ohm's Law
Be very diligent and possibly join a tube amp forum such as AX84.
I have found a few old guys out there who grew up in the tube era and are willing to talk and share their knowledge such as Harry Lythall.
I will never forget David D. yelling at me across the lab, "One hand, one hand!"

Must be cut from the same cloth. I cut my HV teeth in the military and continue to do so today.  :icon_rolleyes:
« Last Edit: September 19, 2010, 08:18:00 AM by Govmnt_Lacky »
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of ‘up to and including my life.’

served

Re: Seems logical to ME!!
« Reply #17 on: September 19, 2010, 08:11:28 AM »
Hi.

I didn't read all this. So I'm sorry if some one already said that.

I do fear high voltages. I have been shocked and so on. But lately If I build something that uses high voltages and I am building it by using a verified schematic, then I will not power it up before I have made some tests, used a multimeter and so on. If I am sure it looks fine, I just plug it in and if it fries then will start again.
Newer really thought about how dangerous it is. I know, I will only make one mistake and then I will not have anymore mistakes to do left. But If I do things the way I am now, then I will be fine.

So for tubes go for a valvecaster at first. Then you know how a tube looks like and what you can expect. Actually it will make you and the Tube friends. You will know it better. Then just power the valvecaster from higher voltage (expect the heater) and there, this is the best introduction. From there, its easy!

R.G.

Re: Seems logical to ME!!
« Reply #18 on: September 20, 2010, 12:44:48 AM »
When I was in my senior year, cars still came with mechanical points for doing an inductive discharge ignition. But capacitive discharge ignition systems were a hot item in the automotive after market. I couldn't afford one, but hey, what's 3.5 years of EE slavery for if not to be able to build high voltage discharge devices?

So I started jazzing up my own homebuilt high voltage inverter and capacitive discharge ignition. This involved running a transformer backwards from 12V and rectifying it to 300-500Vdc in a 2uF capacitor, which was dumped into the ignition coil at the right moment. I had been having some trouble getting this running, but finally got it operating on the breakfast table of my garage apartment. I was fully, completely aware that this hanging garden of electronic parts on the table could deliver a hasty if not fatal shock.

It was winter, and my then-spouse shuffled across the carpet and finger-zapped me on the ear.

It took thirty seconds for my heart to revert to normal rhythm, and I didn't get ANY of the jolt from the high voltage.

It's the little things that mean a lot.  :icon_lol:
R.G.

Quick IQ Test: If anyone in a governmental position suspected that YOU had top-secret information on YOUR computer, how many minutes would you remain outside a jail cell?

PRR

Re: Seems logical to ME!!
« Reply #19 on: September 20, 2010, 01:03:54 AM »
> "One hand, one hand!"

It's good practice. But it will NOT prevent all danger.

The only electric-shock injury which still bothers me was in total compliance with "One Hand!". I was holding a test-probe (bad), with hand braced on chassis (if you are foolish enuff to hand-probe, at least be braced) when the tip of my little finger brushed 600V. 30 years later that finger is still numb.

That one was probably non-lethal (I cudda burned my finger off and still be alive) but this next one WAS potentially deadly. In basement, with rubber-sole (Nike) shoes, I reached to an poorly-covered overhead outlet and it went CLICNK! I had tripped the GFCI by brushing the hot screw, and as far as I could ever figure, the current ran down through my body and out through my shoes. While I doubt even the cheezy "rubber" in athletic shoes will conduct a mA at 120V, there can be traces of damp dirt and foot-salts through the "leather" and down the side of the sole.

And then there's R.G.'s finger-ZAP tale.