Should I be restrictive in my son's interest in electricity?

Question

My 12-year old son has had an interest in electricity for several years now. However, lately his experiments have been becoming more and more extreme. For example, he routinely looks at videos online about "high voltage transformers" (whatever those are) and how to make them at home. He claims to have built a circuit that "exceeds voltages of 2000 volts" and it produces sparks several centimetres long. He recently took apart our broken microwave oven and claimed to extract another one of these "transformers" and a "diode and capacitor". He claims that these components when used properly can "generate voltages upwards of 4000 volts at insane currents"*. I'm starting to get a bit concerned about his safety and am wondering whether or not I should let him continue this interest (however, it seems that he is concerned about safety and has only tripped a breaker once). Any advice on what I should do now is appreciated.


*About the transformer (as it seems a lot of people are getting concerned about it), I found out he was only joking around! He wasn't going to ACTUALLY plug that transformer into mains because he knew that people had died doing so. He was using it as an "inductive load" for a radio transmitter circuit (it works quite well).

Answer 1

I'm no parent, but an electrical engineer. So I will focus mainly on the safety aspects, and on how to push him towards safer branches of electronics.

I think encouraging his interest in electronics is a good idea (plenty of work opportunities for later).

However, except in presence of a competent mentor, at his age, I would strongly advise you to forbid the most dangerous parts of electronics.

My suggestion would be:

• nothing connected to mains (except lab equipment like a lab supply, an oscilloscope, a signal generator, etc., which have plenty of protection against misuse, and where all dangerous voltages are inaccessible). I would even advise against using power supplies connected to main that are not designed for "hobby use" (i.e., avoid laptop supplies, computer supplies, cheap phone chargers, etc., which might offer insufficient protection in case he does a short circuit)
• no voltage above 30V (neither on the supplies, nor that he generates himself)
• no lithium batteries (or at least not without integrated protection): they can explode if shorted or overcharged or over discharged
• no big batteries (above 5Ah) whatever the type
• no big currents (above a few A)

With those limits, the risk is very limited.

Globally, approaching any device powered from mains that is not in an enclosure is to be avoided whenever possible. Doing any tests directly on it requires special training (in France, it's 3 full days of training), and even then is supposed to be done only if it can't be avoided (and then with heavy protective equipment). Working under voltage (other than measurements) requires a 2 weeks training (and there are only 2 training centers in the whole country)

For voltages above 1500V, the restrictions are still far more drastic, and even most electrical engineers/technicians (me included) are not allowed to work with such voltages. Those voltages include new risks, including arcing (ie you can get electrocuted without even touching the wires)

If don't already have one, I would consider buying him a lab power supply (usually those are 2 channels, each up to 30V and 3A), which gives him more than enough power for nearly all "reasonable" circuits he might want to do, while integrating advanced protections (including current limiting, and therefore being able to resist short circuits without problems).

I would then try to orient him towards designing his own (low power) circuits instead of copying circuits from the internet: he will likely learn more. You can help him by finding ideas (if you lack ideas, ask on some electronics forums), for example making a traffic light (either just one, or the whole crossing), making an alarm that goes on if you open a box without pressing the correct combination of keys at the same time, making a little robot always steering towards the light, and so on.

From what you wrote, he seems to mainly be scavenging parts from broken equipment. It might help to steer him in this direction to buy him some parts for low power circuits (those are often difficult to find in recent equipment, as they are often too small to unsolder). You might even make a deal out of it: you buy him some parts he wants (for a given budget) in exchange of him stopping with high voltage/mains.

If he is interested (and he speaks English, otherwise it's a bit harder), it might also be interesting to get him an Arduino kit: the Arduino is a small device that can be programmed, and therefore allows many projects, and teaches him programming); the kits usually include plenty of sensors, actuators and other components

To summarize, I would do everything possible to encourage his interest in low power electronics (forbidding anything high voltage without a mentor).

For finding a mentor if you/he wants one, I would suggest looking at:

• electronics clubs
• robotics clubs
• radio clubs
• fab labs
• repair cafes or similar (i.e., places where people try to repair equipment)
• ask the physics teacher to create a club at school

If you can't find one, then maybe go for some books (I would suggest getting an extensive and advanced kit, with a good instruction manual. This way, he has both the instructions and the hardware to build with, and it's far less likely than on the internet that he will find anything dangerous in there.)

Answer 2

Your son needs a mentor who is experienced in electricity and especially electrical safety. The components he is experimenting with can easily kill a person.

To compound the danger, the ability to competently assess risk is not usually developed in someone at age 12. He may or may not be able to deal with such a serious risk, but you cannot afford to assume he can.

Until he has an adult you trust who knows the ways of electricity to advise him, please restrict his electrical experiments to low voltage, such as that provided by D cell batteries and the like.

People have died emulating experiments found on the internet using microwave transformers and the like. This is no joke.

Resources

Dozens of people have died using microwave transformers to do "fractal" woodburning: Debunking DEADLIEST craft hack, 34 dead by Ann Reardon (youtube)

Answer 3

Let me give an answer from the perspective of an electronics hobbyist who was once a precocious child myself.

The other answers here give very reasonable sets of rules of a kid playing with electricity. However, I'm worried that a total ban with little explanation is not going to sit well with your son, and I'd be concerned about him sneaking around behind your back, if he thinks you're overreacting in an uninformed way.

One thing I think is very important, in that context, is explaining levels of risk. I do think, with good expert guidance, a kid could learn to safely experiment with wall power. (I would say the same thing about most adults, to be honest. The important criterion here is not age, but maturity and level of caution.)

I'm a 38-year-old electronics hobbyist, and I do sometimes play with wall power (carefully, and almost never on anything live.) I've been shocked at 120V twice. Once was from a nicked wire on a string of Christmas lights I was putting up. The other time was from a very old computer, disassembled and with the power switch turned off. (The input terminals of the power switch were still live, whoops. Important lesson.) Both were painful but neither was deadly (although the computer probably could have been, if I was very unlucky.)

Making brief, weak contact with 120V is likely to be painful, and very startling. But with dry, intact skin, it's not all that likely to be fatal. But microwave oven transformers (and similar high-voltage moderate-current sources, such as neon sign transformers) are another story, and your son probably doesn't realize that. At 2,000+ volts, a microwave oven transformer will readily overcome the resistance of even dry skin. There is a much greater chance that even momentary, incidental contact will cause death (by stopping the heart instantly) and/or severe burns.

Here is a research paper with a list of people who have been seriously injured or killed, using high voltage sources (usually microwave oven transformers) for making art: https://www.researchgate.net/publication/341057805_Death_Due_to_Fractal_Wood_Burning_An_Emerging_Public_Health_Problem . Of the 25 reported individuals, 20 died, and 3 of the other 5 had to be revived after their heart stopped.

If your son is like most people (including myself as a child, I'm sure), he will bristle at the idea that he could make a mistake. So I must emphasize that no blatant mistake is required. Ask him to consider whether he's ever been in a position where he might contact live wires, even momentarily, if one of the following had happened:

• A door slamming / car backfiring / other startling loud noise?
• A minor earthquake, causing him to stumble and fall into equipment, or causing equipment to shift or fall? (If that sounds like a bizarre rarity, forgive me, I'm from California.)
• A failure of a circuit component, leading things to be connected in a way he didn't intend, even briefly? (Connections between low- and high-voltage circuits in consumer electronics use special components, such as Class X/Y capacitors, with an exceptionally low chance of failing in this way. Is he aware of this type of protection?)
• A failure of power company equipment, leading voltage at the wall to be (briefly) much higher than expected?

Test equipment, such as voltmeters, have safety category ratings, CAT I through CAT IV, based on what they are considered safe to connect to. Even a CAT I meter might be capable of measuring 120V -- but it's not considered safe for use on an electrical outlet. Because it wouldn't be safe if something went wrong while you had it connected. These are the safety rules that professional adults follow, because sometimes things do go wrong, and you don't want your life riding on luck.

Obviously people do also make mistakes! But mostly people (again including adults, even professionals) are resistant to acknowledging their own fallibility. So I always prefer to emphasize all the other ways that things can go wrong.

I have no specific advice on what to allow your son to do. But I hope you can use this information to give him some food for thought, about why things might be riskier than they appear (and why microwave oven transformers are fucking scary, and I won't mess with them.)

Answer 4

Unless you have good understanding of your son's experiments (and are able to assess their safety), you should not let him play with anything in excess of SELV (Safety Extra Low Voltage) range. The exact definition of "safe low voltage" varies by country, but in general voltages <50V AC and <75V DC are not fatal in ordinary circumstances. This means you won't die if you accidentally touch a bare wire with your hands, provided your hands are dry, unwounded, etc.

In general, if you don't share you son's passion, you'll do him a favour by finding a local club where he can learn new things, in addition to being supervised.

Answer 5

Firstly, I should mention how wonderful it is your child is interested in electronics at such a young age. You should encourage his passion.

However, playing with microwave transformers is VERY dangerous. Basically, a transformer increases the voltage of AC current by some ratio. If he made a mistake, however unlikely, it could easily kill him. I would strongly suggest you ban any use of high voltage transformers.

Other electronics projects are far less dangerous. Playing with a wall outlet is more likely to give a nasty shock than kill someone, but it still probably isn't a good idea (it can cause burns, and definitely can kill in the right circumstance).

As mentioned in this thread, buying a low voltage power supply is a good idea. Low voltage electronics is quite safe. Buy him the tools he needs to make interesting projects at low voltages. Given that he's already working with transformers, he'll probably like a more advanced kit than those for children.

(I'm a 3rd year engineering student btw)

Answer 6

I'll start with a quote by Mark Twain:

Soap and education are not as sudden as a massacre, but they are more deadly in the long run.

The sudden effects of electricity might seem like the bigger danger, but I myself experienced more than 30 years of emotional neglect and discouragement.

I hope you get the message.

Should I be restrictive in my son's interest in electricity?

No.

Instead:

1. Support his interest.
2. Take appropriate safety measures.

What is appropriate?

About the "30 V limit" and "no lithium batteries" rules ...

You can kill even with a 12 V power supply. It's not simple, but possible. Igniting a fire and burning down a house with 12 V is rather simple.

Getting a mentor who is experienced in electricity is – IMNSHO – by far the best approach. Especially to understand the real dangers associated. Preferable this mentor should have played with dangerous stuff as a kid himself ;-)

Making sure your son doesn't plug a high voltage transformer to the mains power supply is certainly an appropriate safety measure – however you implement that.

By reading your post I suspect you have very little knowledge about electricity. Please, don't just impose a "30 V limit" on him. I hope you understand that this kind of restriction goes "over the top" (to use your own phrasing).

My direct advice:

Encourage your son to play around, but also tell him that you want him to stay alive.

Then ask him to impose restrictions ON HIMSELF.

He probably knows for himself (most likely better than you!) what is dangerous and what's not. And if he doesn't know yet - tell him to research! That way you really support him and his sense of responsability. It will make him stronger, because you show your respect for him and his judgements. This way it is also very unlikely that he may disregard the restrictions, because he himself put them in place.

PS: I'm an Electrical Engineer, 41 years old, now working as a Coach for Communication

Answer 7

Apart from all the correct advice in the other answers, amateur/ham radio used to be a discipline for enthusiastic kids to play with electronics. Maybe there's a club near where you live.

Answer 8

To be honest it sounds like a healthy knowledge-enriching pursuit. My kid likes killer ants. Nothing wrong with things like this, from a parenting standpoint - you just need to ensure their safety.

Why dont you buy him those "200 in one" electronics kits.

When he's done with that, encourage him (books, videos) to learn physics.

Using parts from old mains-voltage appliances sounds dangerous - I would define limits on what he can and cant play with.

Incidentally if your kid has the "engineer" mindset, they may also like programming, minecraft and things like that.

A trip to the technical museum (or the Smithsonian if you are in USA) could also be very rewarding for them. Particularly the part where you touch a steel ball (under safety of the museum staff) that charges up to 20.000 volts and your hair stands on end. This is so cool for kids.

Answer 9

As a child I experimented with fire and home-made explosives and tried to make a gun using copper tubing - luckily that experiment failed. I never told my parents and they didn't know until I blew a sizable hole in the back garden by burying a home-made 'bomb' under two feet of earth and running a cable back to the house where I plugged it into the 240V (UK) mains.

I was very lucky to survive without serious injuries.

The fact that your son has confided in you is hugely important. My suggestion would be to encourage his interest and even join in with them but encourage safe low-voltage experiments.

Example

My father taught me how to use tools. I always remember his warning never to use a sharp knife to cut towards yourself. He described in detail what had happened to one of his friends. To this day I am very careful with knives.

Explain to him that a high voltage that passes through the heart can kill you instantly. This usually occurs when touching a live source with one hand and an earthed (grounded) object with the other. It's a well-known hazard for musicians who touch a microphone whilst holding a grounded guitar.

If you educate him thoroughly in the safety aspects, he will feel like an expert and take pride in being safe. personally I wouldn't shy away from showing him pictures such as the one shown in the following link. https://www.researchgate.net/figure/A-22-year-old-male-with-high-voltage-electrocution-of-the-upper-right-extremities_fig2_261596170

As others have said, encourage him towards safe voltages and praise and encourage any projects he makes and especially praise the built-in safety aspects.

Answer 10

Try to direct him from the high voltages that are anyway not very common in modern electronics. In these days, everyone is trying to run devices at lower voltages instead to use less energy (used to be 5 V, now 3.3 V is common, CPU cores often run at below 2 V). The vacuum tubes with they high voltages do have something attractive in them but in general are now as relevant as steam engines.

For instance, there are many very interesting robotic kits (like robotic arms). Large industrial models are strong enough to be careful with, but there are also learning devices for students that are both much cheaper and the manufacturer should have thought about they safety. Check the recommended age range.

Do not buy some Lego-like robot programmable with user friendly application where you need to connect squares with arrows. Buy that looks more like a real thing and can be programmed with a real programming language, creating more a feeling the he learns something sensible. This feeling may provide lots of internal drive that is more important than the results being easily available.

I suggest to to enter the world of ROS, Linux and Python or C++ where I earn for life myself. Here is the curated list of ROS supporting robots, including the ones that fly and the like. Discuss with your son the possible robots, which one he likes the most. You may need to invest some of your time if the son cannot get the robot going on his own.

P.S. Safe voltages are generally considered below 36 V in normal dry conditions. I am not aware of any single learning kit that would operate with higher voltages.