There seems to be inconsistency regarding which threads dealing with high voltage get locked and which do not.

Specifically, some threads dealing with ignitions and fly-back transformers have been locked, while others dealing with those subjects and Tesla coils have remained active.

What is the policy at AAC with regard to discussion of projects entailing high voltages?

John

 

Like my plasma speaker project? (BTW, not going well )
I would also like to see a clear set of rules, I recently created a profile at 4HV (same username) to talk about my "less safe" projects, but I would like to know what can and can't be posted here, so as not to start any bad threads.

 

Administration has been PM'ed for a policy clarification.

 

Hi magnet18,

My comment was not directed at your project at all. In elementary school, I was messing with neon sign transformers (>50 mA @ 5000V?), Tesla coils, and Jacob's ladders. In high school, mercury (that's right) diffusion pumps and Van de Graff generators, and a 500KV linear accelerator. It was interesting; I had no supervision. When I couldn't walk into the room ("my laboratory") due to the static charge and saw a 17" arc to a nearby motor, I got scared and cut the main power to the room.

In retrospect, I was very lucky and some supervision would have been appropriate. Today, I would like to be able to discuss internal combustion engine ignition circuits. And, I think with some care, you should be able to pursue your plasma speaker. But, the Forum's policies seem to be applied inconsistently, and that is the reason for this question.

John

 

An 11 year old with a neon sigh transformer!
sounds like a bad idea, I'm barley allowed to play with flybacks

 

I've had the same thought. Personally I would like to see more discussions of these natures, but I also know there are young people just dying to try some of this out, and I want to keep that figurative.

 

I agree, saftey comes first, but that being said, a little plasma arc will do a lot more to motivate the modern teen to become intrested in electronics than a 4017 flashing some LED's will. (No offense Bill)

The time when a crystal radio was considered cool has long gone by
(That was the first thing I built, way, way back in 2006 )

 

Yes, and we have preteens here too. Keep it in mind youngster. If you had a little brother, would you want him playing with 20KV? Or even with raw line voltages?

LEDs circuits can teach a lot about basic electronics, and are completely safe. How much do you really think you know about LED circuits and the electronics driving them, given they are oscillators, switching circuits, pattern generators, and power supplies? The technology is going to LEDs, and away from high voltages.

 

LEDs circuits can teach a lot about basic electronics, and are completely safe.

Nothing is completely safe. That's the crux of the issue. Little kids, even preteens and teens, put things in their mouths and can choke on them. Chips and resistors can get hot enough to burn little fingers. Capacitors can explode. Chips will sometimes pop (safety glasses). Lead solder is not good to chew on. Copper beryllium alloys are poisonous. We have all seen posts where a young poster was bragging about his latest explosive event, ad nauseam.

On the other hand, the forum will suffer if it is limited to LED's and 9V or less. Coil guns and related projects are dangerous. I think a line needs to be drawn between the extremes.

Individuals may decide to lower that bar based on their own risk tolerance and location. The American rule allows anyone to be sued for anything -- the family of the guy who stowed away in the jet wheel well and ended up dropping in unexpectedly on a NY neighborhood are suing the airline.

Lawsuits involving previously anonymous actions on the Internet are becoming more common and costly. American courts have had little problem in lifting that protection. AAC needs to protect itself. Individuals need to do likewise. The worse situation I can imagine is to have a policy and not follow it consistently. Claiming an editorial action based on a non-existent or very vague policy is probably a close second.

John

 

I've been a vocal activist for posting a addition to the rules, starting with the thread "Things that get your thread closed". So far nada. I am under the impression it was thought to be a good idea, but somehow it never happens.

I don't have any good answers other that what I've alread suggested.

 

I only play with circuits not more than 12 or 24 volts. All those are from the batteries. I have been restricted on using 120 volts or more than that.

 

<grin> Your not the only one I was thinking about. I am enjoying watching you learn.

 

I only play with circuits not more than 12 or 24 volts. All those are from the batteries. I have been restricted on using 120 volts or more than that.

That is a good thing, restrictions are to keep us safe. Someone as new to electronics as you shouldn't be messing with the mains voltages (I've been following your posts also). I have restricted myself to not doing anything overly lethal. (no microwaves, always discharge the caps on things like power supplies and don;t run them while they're open, ect...

Theirs plenty of fun to be had without the mains, I know I don't use them unless absolutely necessary (only once), and I always have a GFI in place and my father around

@bill, spoken like a true teacher

 

Which is more lethal, AC or DC? Or they are just the same?

I think, I can only use the mains voltage after I mastered electricity or mastered its basics...

 

if there's one thing that upsets me in this regard, it's internet sites which invariably seem to insist on these heavy-handed and basically meaningless disclaimers... "bla bla Mains Voltage... bla bla DEATH, bla blagh don't even think about, bla bla KILL"... a few skull and crossbone symbols and so on.
it's not the attempts to avoid horrendous stupidity or horrible accidents (or legal actions) which bugs me per se. it's just the general tone of fear over education which puts me off.
as a young child i personally made contact with line voltage a couple of times. i'd blame one occasion on lack of education and the other on dumb curiosity. i've noticed a very small percentage of sites on the web which would even come close to actually explaining why a person may or may not end up dead from such an encounter.
there really seems to be this kind of cut and dry presentation of electronics as being: "line voltage=deadly...don't even think about it" / "batteries=fun safe... no big deal".

I only play with circuits not more than 12 or 24 volts. All those are from the batteries. I have been restricted on using 120 volts or more than that.

i've got a bag of disposable devices here which each run on a single AA battery.
1.5 volts.
each unit contains a little capacitor rated at 80μF, 330volts. now correct me if i'm wrong, but these little components can deliver quite a shock... almost 4.5 joules... they'll hold a charge for months.
i really had to wince every time a discharged one. a shock from 3 of these at the same time, however unlikely, could do more than just cause pain and make one's jaw lock, it could make one dead.

now is it likely that some kid is going to end up with a supply of potentially lethal caps and not realize the dangers? maybe not, but don't underestimate the power of mild dyslexia and even typos for that matter... i was picking up a list of components for a project once and the shop keeper plunked a capacitor the size of a large beercan on the counter. i must have accidentally added a zero on there somewhere.

anyway. i hope i made my point.

 

i've got a bag of disposable devices here which each run on a single AA battery.
1.5 volts.
each unit contains a little capacitor rated at 80μF, 330volts. now correct me if i'm wrong, but these little components can deliver quite a shock... almost 4.5 joules... they'll hold a charge for months.
i really had to wince every time a discharged one. a shock from 3 of these at the same time, however unlikely, could do more than just cause pain and make one's jaw lock, it could make one dead.

now is it likely that some kid is going to end up with a supply of potentially lethal caps and not realize the dangers? maybe not, but don't underestimate the power of mild dyslexia and even typos for that matter... i was picking up a list of components for a project once and the shop keeper plunked a capacitor the size of a large beercan on the counter. i must have accidentally added a zero on there somewhere.

What? I did not get your point.
@the topic
If a child or a kid knows what he/she is doing, I'm sure he won't do something that will make himself/herself dead! Secondly, the parents knows if their child is already matured enough to do those dangerous stuffs. If ever they think their child is not yet matured enough and really don't know what their child is doing, why would they give their a child a stuff that would make their child die? :O:

It's up to the child, teen or so whatsoever. If he knows what he/she is doing, I know he will succeed and he will not be in trouble.

Yes, anything are dangerous if you will not be safe enough. But one more, there's a less dangerous, dangerous, worse dangerous, and WORST dangerous. It's up to you if you will going to use or give the WORST dangerous!

 

What? I did not get your point.

just because it's only battery powered does not always mean it's safer than line-voltage to work with.
i guess i'm just using the word "kid" rather inclusively in terms of age. experience and responsibility kids.
i'm just asking if it's more useful to just try to frighten people, or to educate them.

 

Most battery circuits do not involve high voltage. It is not something you do accidentally, and it isn't easy. Even a relay tinglier will not charge a capacitor, so most of the comments here are bogus. Keep it real folks, it is getting rather thick.

 

Gee, the B batteries in my old 27.225 MHz transmitters were 135V. That was enough to give a tingle.

John

 

Most battery circuits do not involve high voltage. It is not something you do accidentally, and it isn't easy. Even a relay tinglier will not charge a capacitor, so most of the comments here are bogus. Keep it real folks, it is getting rather thick.

yeah. nice.

voltage in a disposable camera capacitor!
http://forum.allaboutcircuits.com/showthread.php?t=10850

Be careful. You can kill yourself by creating a current path through your torso.
When dealing with high voltage circuits, keep one hand in your back pocket.

i've read that standard disposable cameras can deliver 500V at 120A.

It is not too dangerous, but definitely an experience to remember.

I once held the whole disposable camera flash circuit including battery and fully charged, by the edges, and it accidentaly slipped and touched my hand with all the pins on the bottom side. The jolt was really shocking and the hand (palm) was a bit paralized for few minutes. I was like ten years old, so that is how my first contact with high voltage looked like

further, though i'm not really able to totally verify the story, i've read about an incident in Sendai-shi Miyagi-ken, Japan, in which a student was killed by a battery-powered camera flash unit. an ACCIDENT which occurred due to lack of knowledge about the dangers. taking apart a battery-powered camera flash unit is actually pretty easy to do.

my point: that not all battery-powered circuits are safe,
still stands.