My son needs me to help him with a school project--a simple circuit with a switch. He said he wants to use a light bulb, a switch, and have it plug into the wall. Is this inherently dangerous? BTW, he's in
9th grade and says he saw a setup like this on the teacher's desk. Thanks.
Dear heavens, of course it's dangerous...it's the very same sort of electricity they use in electric chairs, after all. Wouldn't your son's school project be much safer if he just devised an interpretive dance expressing his disgust at the raping of Mother Gaia by greedy capitalism?
Bill
( who by modern standards shouldn't have made it past his 10th birthday...but I was an unusually cautious child for my era.)
Of course it is dangerous, but not overly so. Life is dangerous. Riding in cars is dangerous. Working underneath cars is dangerous. Working on something like that will teach him to be careful. I was working on such "dangerous" things when I was in high school.
If you want to greatly increase safety, although not completely eliminate it, use a GFCI extension cord. GFCI stands for ground fault circuit interrupter. These are readily available at many hardware stores.
Bill
Why not use a lantern battery? You can get the battery, a knife switch and a small low voltage bulb and ceramic screw socket from ACE hardware. The parts are in the pull out bins where small parts and fasners are located.
My s>My son needs me to help him with a school project--a simple circuit
I built a Tesla coil with the primary fired by an oil furnace ignition transformer and miscellaneous junk, for a high school science project. I never did get them to believe that it was safe. Schools weren't the trusting sort even thirty-something years before DHS. ;-)
No, I don't think its really dangerous, considering for a 9th grade student. He can easily do it Make sure neither of you touch the live copper wire or insert any material(like stick, knife, screw driver) into the plug point. First do all the circuit connections and then connect the circuit to supply. This will take all the gaurd necessary.
Make the 'plug' a low voltage wall wart and there shouldn't be a problem. I'm thinking 12V max.
Assuming no exposed conductors, what is being built is basicly a lamp fixture. Perhaps something at this site will insipre a project:
Of course, but so is riding a school bus.
BTW, he's in
Before grade 6 I installed lights and motors in a "time machine" a prop for a play I build out of a cardboard supermarket display.
By 12th grade I was already troubleshooting AC systems and installing AC outlets and lighting including bending conduit.
Your best help would be to refer your son to someone qualified to help him if you know what I mean.
Better off using a DC light bulb socket, bulb, and a switch.
Yes, AC can be dangerous. If there are any exposed contacts, then the AC will be available for human contact, and that is a bad thing.
With low voltage DC, the most that can happen would be a hot wire causing a burn in the event of a short.Not really much else could happen.
Maybe he should build an electric chair instead!
I got zapped by a 10kV Jacob's ladder at ten y.o.a.. I guess you are all lucky I survived the event.
When I say "I am the sanest person in the shop" at work, and my head jerks, it isn't fake. :-]
I had a Jr High Sch "science" project that was a transformer, a switch, and a battery with two electrodes coming off the transformer.
I called it a "Lie Detector". You wouldn't believe the number of "takers" I had.
Someone would tell me their age, and I would jolt them and say, the box says you lie, smiling. He replies, "but I am not lying." I laugh a bit, and say "The box does not lie."
Quite the bit of science, that was. I should have gone with a Tesla coil or Jacob's ladder.
Assuming that this is intended to be a learning experience, I would suggest that there are two alternatives:
1) Learning by trial and error and experimentation 2) Learning from an expert (eg book or person)The first is arguably more fun. However, allowance has to be made for errors. Either there needs to be someone present to step in when things get potentially dangerous - or the capacity for danger has to be intrinsically low. This means having someone present if the energy source is powerful enough to kill, seriously injure or cause a fire. Which "household current" is. A potential fire risk exists, even with GFCI and a circuit fused at 1A.
The second is arguably more efficient and certain. However, a book without tutorial support can lead to misunderstanding and error.
Thus, if someone is present with enough expertise to protect the student from errors which could be fatal - by all means let him use mains power, wiring and equipment. The "someone present" could simply be someone that the student calls when he is ready to apply mains power - who examines the system and gives the OK to apply power.
If no such person is available - then a low voltage, low energy, power source will ensure that his learning experience of terminals isn't terminal. Note "low energy" - giving students multi ampere hour "car batteries" to play with is arguably more dangerous than a mains outlet..
As is common, I learnt by trial and error using 240v 15A outlets, large lead acid batteries, etc. In days when Boots the chemist would sell a teenager flowers of sulphur, saltpetre, etc over the counter. A teenager with the odd burn or two could go to casualty without the parents being given the third degree by Social Services.. My parents were of the "Better drowned than duffer - if not duffer, won't drown" school. However, in the UK at least, society has moved on to more "enlightened" attitudes..
On Sun, 09 Dec 2007 00:02:25 -0800 ChairmanOfTheBored wrote: | On Sat, 8 Dec 2007 17:33:23 -0800 (PST), Bayou Self | wrote: | |>My son needs me to help him with a school project--a simple circuit |>with a switch. He said he wants to use a light bulb, a switch, and |>have it plug into the wall. Is this inherently dangerous? BTW, he's in |>9th grade and says he saw a setup like this on the teacher's desk. |>Thanks. | | | Better off using a DC light bulb socket, bulb, and a switch. | | Yes, AC can be dangerous. If there are any exposed contacts, then the | AC will be available for human contact, and that is a bad thing.
So 120VDC is safe?
| With low voltage DC, the most that can happen would be a hot wire | causing a burn in the event of a short.Not really much else could happen.
So 12VAC is dangerous?
| My son needs me to help him with a school project--a simple circuit | with a switch. He said he wants to use a light bulb, a switch, and | have it plug into the wall. Is this inherently dangerous? BTW, he's in | 9th grade and says he saw a setup like this on the teacher's desk.
I thought they quit using the Darwin effect to raise the average IQ.
Show me where I ever said anything about 120V DC, or for that matter, show me where ANYONE in industry, much less consumer electronics, or home improvement uses 120V DC.
You could be a little more retarded, just not today.
So much for you thinking, Darwin boy.
Edison vs Westinghouse, round 2.
;-)
On Sun, 09 Dec 2007 09:28:57 -0800 ChairmanOfTheBored wrote: | On 9 Dec 2007 17:20:42 GMT, snipped-for-privacy@ipal.net wrote: | |>On Sun, 09 Dec 2007 00:02:25 -0800 ChairmanOfTheBored wrote: |>| On Sat, 8 Dec 2007 17:33:23 -0800 (PST), Bayou Self |>| wrote: |>| |>|>My son needs me to help him with a school project--a simple circuit |>|>with a switch. He said he wants to use a light bulb, a switch, and |>|>have it plug into the wall. Is this inherently dangerous? BTW, he's in |>|>9th grade and says he saw a setup like this on the teacher's desk. |>|>Thanks. |>| |>| |>| Better off using a DC light bulb socket, bulb, and a switch. |>| |>| Yes, AC can be dangerous. If there are any exposed contacts, then the |>| AC will be available for human contact, and that is a bad thing. |>
|>So 120VDC is safe? | | Show me where I ever said anything about 120V DC, or for that matter, | show me where ANYONE in industry, much less consumer electronics, or home | improvement uses 120V DC.
Read the quoted text. It's saying something is dangerous because of the nature of the electrical system, rather than it's voltage level. I brought up 120VDC to show the misdirected statement about danger.
|>| With low voltage DC, the most that can happen would be a hot wire |>| causing a burn in the event of a short.Not really much else could happen. |>
|>So 12VAC is dangerous? | | You could be a little more retarded, just not today.
So why did you say "DC"? Why not just say "With low voltage, the most that can happen would be a hot wire causing a burn in the event of a short. Not really much else could happen."
Your incomplete and off-target statements can be misleading.
On Sun, 09 Dec 2007 15:15:45 -0800 Paul Hovnanian P.E. wrote: | snipped-for-privacy@ipal.net wrote: |> |> On Sun, 09 Dec 2007 00:02:25 -0800 ChairmanOfTheBored wrote: |> | On Sat, 8 Dec 2007 17:33:23 -0800 (PST), Bayou Self |> | wrote: |> | |> |>My son needs me to help him with a school project--a simple circuit |> |>with a switch. He said he wants to use a light bulb, a switch, and |> |>have it plug into the wall. Is this inherently dangerous? BTW, he's in |> |>9th grade and says he saw a setup like this on the teacher's desk. |> |>Thanks. |> | |> | |> | Better off using a DC light bulb socket, bulb, and a switch. |> | |> | Yes, AC can be dangerous. If there are any exposed contacts, then the |> | AC will be available for human contact, and that is a bad thing. |> |> So 120VDC is safe? |> |> | With low voltage DC, the most that can happen would be a hot wire |> | causing a burn in the event of a short.Not really much else could happen. |> |> So 12VAC is dangerous? | | Edison vs Westinghouse, round 2.
My point is that, for the most part, it's not about AC vs. DC in terms of the safety factor for student science experiments. There is some degree of hazard for steady DC at high levels where common circuit breakers may not be able to break the current. But those are much higher levels than students should be working with. Lower voltage and lower current is where the safety is for this kind of application. That and appropriate adult supervision for the higher levels of this.
On Sun, 09 Dec 2007 09:29:28 -0800 ChairmanOfTheBored wrote: | On 9 Dec 2007 17:21:44 GMT, snipped-for-privacy@ipal.net wrote: | |>On Sat, 8 Dec 2007 17:33:23 -0800 (PST) Bayou Self wrote: |>
|>| My son needs me to help him with a school project--a simple circuit |>| with a switch. He said he wants to use a light bulb, a switch, and |>| have it plug into the wall. Is this inherently dangerous? BTW, he's in |>| 9th grade and says he saw a setup like this on the teacher's desk. |>
|>I thought they quit using the Darwin effect to raise the average IQ. | | | So much for you thinking, Darwin boy.
OK, so they still use the Darwin Effect. How did you get past it?
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