If you have had it with persistent weeds that seem to come back no matter what you do, here is an ‘environmentally friendly’ way to kill them off permanently. By using a probe charged with 2400 Volts, [Jack] shows how you can conduct the electricity through the plant and all the way down into its roots while scorching the living daylights out of what sits above the ground.
Check out the video after the break….
Before you get to the video, a word of warning. In this video [Jack] takes apart a microwave oven. Microwave ovens can cook meat. You are made out of meat. DO NOT power up your microwave in a half assembled state with the magnetron still connected. Also, since microwave transformers can produce high voltages, you should be extremely cautious about what you touch while the transformer is connected to wall power. The electricity coming out of the microwave transformer can kill you. It won’t be slow and it won’t be funny so be careful.
In this video, [Jack] initially has the transformer wired up incorrectly. Below is a picture of how things should be connected.
Thanks to [Grenadier] who helped to make this video a success. We have featured several of his projects here such as this one where he wound his own transformer to make some incredible arcs.
—- Update —-
A recent trip to the office park seems to show that this was a success. There are many different individual plants in the bunch but the ones that actually were hit by the high voltage are yellow and dead. The others right next to where we were zapping are not looking as healthy as other plants nearby.
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Id stick to robots if if I were you
I’m not trying to be negative here but… Do these ridiculous disclaimers really mean anything? “Hi. Here is this insanely dangerous but highly interesting thing. Oh, and here are all the details on how to do it. But don’t try this at home!” Does the HAD house lawyer demand this foolishness? The level of hypocracy is beyond comprehension. If you are going to post it, then own it.
If you kill yourself, it’s your fault.
It’s the closest thing they could actually buy from a lawyer that would mimic a magic incantation to prevent stupid people from hiring other lawyers to cost you money in legal bills even if the stupid person’s case was without merit.
Today’s litigious society, brought to you by the Lawyer’s Guild, judges (but I repeat myself), and politicians (but I repeat myself yet again).
You do realize, this is a site in the internet in english language? You do realise, you can file a lawsuit for almost everything in America? (e.g. a woman filing one against MacDonalds for the coffee jugs not having a line of text saying “HOT” on it). Now think why hackaday won’t stop saying that people should be extremely cautious about what they’re doing.
The women with the hot coffee is a legitamate legal claim. She had the coffee burn through the skin to the point of needing skin grafts. The coffee was being served at 180-190 F. She was one of more than 700 claims about the temp of the coffee. She asked for medical bills compensation only, the jury decided one day’s worth of coffee profits for McDonald’s would be a good punitive damage. She tried to settle numerous times, her case is a textbook example of things changing quickly from a lawsuit. McDonald’s now serves coffee at around 140
@ Hammerhead
Sure, you can file just about any lawsuit, but thanks to the centuries old practice of obfuscated legalese mischief, without paying a member of the lawyer’s guild to pull the strings on your behalf, you’ll likely see your case dismissed with prejudice in less time than it takes to search-fu up the phrase “pro se”
Now we are talking.. Hook this up to that weeding robot and you are in business.
Since it’s not the voltage that gets you, how many amps? (I am videoless at work).. Any danger to nearby plants?
“it’s not the voltage that gets you” is one of the most repeated and wrong statements about electricity that exist. Voltage represents electrical pressure, and current electrical flow. Depending on where that voltage is presented, you might be very surprised to learn that the level of current required to seriously injure or kill you is lower than what you’d get out of an AA cell.
Anyone reading HAD knows about Murphy’s laws. Don’t tempt him! High voltage is *fun* to play with, but be safe and use your brain. Don’t screw around with high voltage alone.
Actually, you contradict yourself.
Voltage isn’t what kills you. If it did, you’d die every time you scuffed your foot on a carpet and grabbed a door knob.
What kills you IS CURRENT. So, if you think high voltage can kill you, it’s only because it’s not suitably current-limited.
But, folks need to be aware, your body is a resistor, and like any resistor, conforms to Ohm’s law. Depending on your skin resistance, high voltage sources without current limiting will cause enough current to flow to disrupt neurological and cardiac function.
I want to make clear that the problem is lack of current limitation, not the voltage. Any high school kid who built a Van de Graff generator can equally demonstrate this first-hand.
To clarify: it is the energy present at a specific location and circumstances that can kill you.
~1.3V directly across the heart muscle will kill you, provided the source can provide about 10mA (note: if you have a hole in your chest that lets bare wires touch your heart, I suggest you take a break from hacking)
There has to be enough voltage to make current flow in whatever situation. Once current flows, work is being done and the energy of the system has to be taken into consideration.
Be aware of what energies your system has, and when in doubt, keep a hand in your pocket (current across your heart is dangerous, current down your arm is annoying, and less likely to cause permanent damage).
It’s not the volts that’ll kill you, it’s the stupid that will (and the reckless, the inattention, and the unthinking).
Interesting idea, but the video was lacking. You don’t tap the wires of a Jacob’s Ladder, and the sparking and popping isn’t what a Jacob’s Ladder is. The presenter seemed to know this, yet continued to use the wrong terminology. Perhaps a second vid on how to properly position and form the leads to make a real Jacob’s Ladder would be a good video, but this brings me to my next point…
This would have been MUCH better as a well-written up instructional text with pictures. Watching someone build something that does NOT require any kind of special or tricky movement makes for a tedious thing to watch. This would have been great in text form, where it’s easy to scan and see the interesting bits. The video on magnetic levitation is a perfect example of when to use a video instead of text.
I really enjoy HAD, and I applaud the presenter for doing something and showing the rest of us… but please don’t turn this into another youtube — use video judiciously.
actually you need voltage and current to kill you. one millionth of a volt at a million amps isnt going to harm you and a million volts at one millionth of an amp (e.g. static from rubbing your feet across the floor) isnt going to hurt you either.
Actually current is the killer – you need the voltage to induce the current which kills you. If both killed you it would be like saying my murderer and his mother killed me. She was necessary but didn’t do the killing herself.
@cmbrodman
That’s a poor analogy. Try this:
A person with a gun killed me. The gun was the murder weapon, the person pulled the trigger.
Instead of arguing about voltage vs current being dangerous, we should just agree that electricity can be quite dangerous and should be used cautiously.
The disclaimer in the writeup seems much more appropriate than in the video. I’m all for informing people when something they’re about to do is horribly dangerous, and how it could cause harm. Thanks for letting me know; I’ll use caution.
Telling people not to do something, then showing them how is just dumb. IME, hackers typically hear “don’t do X” as a challenge.
Disclaimer critique aside, I’m a little confused about this post. Does this method actually kill the plant, or just burn the bits you touch?
That is still to be determined. I checked in on the plant today and it seems like it may still be alive. Hardy plants can take some time to look dead though. The guy who showed this technique of weed killing to me swore by it for the weeds in his yard.
Little problem with using high-voltage. While this is only at 60Hz (As opposed to a tesla coil up in the KHz), there is still going to be some skin effect, where the current is going along the outside of the plant. Also, the HV is going through the water in and on the plant, so I highly doubt that the current is going past the soil level before just going through dirt. Electricity itself isn’t likely to kill the plant, but perhaps if you stuck the probe right in the middle of the stem/heart/trunk of it and let it cook for a bit, the heat itself could kill it. Still doubtful that it’d kill the roots, however.
It is impossible for this hack to kill the plant, I think, because of the root system. Consider the dendritic structure it has, and attempt to look at it and its interface to the soil (essentially treatable as perfect ground) as a Norton or Thevenin equivalent circuit. What you’ll find is a surprisingly low resistance to ground.
In other words, the plant won’t feel a thing, except for surface scars.
I call for your consideration how many trees, when struck by lightning, continue to thrive, despite superficial scarring or splitting. The tree survives such a blast through similar mechanisms.
Darwin Bats Last.
Neat Hack and not to be at all disrespectful of the project by my comments- it’s just that anything that makes for dramatic Darwinbaiting risks a wave of scrutiny about/AGAINST all Hacking that could Deeply and Truly SUCK if someone kills anyone this way- even suicide by stupid is a strike against us..
Stuff like this is a “Potential” case for VERY accelerated natural selection. Both of plants and soon-to be *DEAD* humans. The instant Lethality of these power levels is way underestimated due to the CURRENT supplied.
IF there were text instead of merely a viddy? I’d uprate this a lit higher too. the video shows the “what” but the other applicable “W”s are lost in most videos.
Yes- it’s a very seductive “Gee Whiz” Technogreen hack. Run by a Roboweeder? And, if it were somehow packaged in a roll over the weeds safety box with proper interlocks, it might someday be practical. Box meaning any screen grid or solid metal – to prevent HV from finding ground through humans or animals etc.
You forgot to mention the diode in the HV circuit. Together with the capacitor it forms a voltage doubler circuit and is pretty fundamental to the way the magnetron is powered.
The two terminals on the magnetron connect to the heater which is a low impedance circuit. There should only be a few volts between them, but they are both raised to roughly -5kV from ground by the doubler circuit.
A slightly safer slternative: have you looked at the coil on plug modules you find on modern automobiles? Many have an inbuilt ignitor circuit which you feed +12V at several amps and a 5V TTL level pulse to trigger a spark. They are capable of firing at kHz frequencies and putting a few watts of HT power out. Much less than a microwave transformer, but also much less likely to kill someone when you wire it up wrong :-)
Your warnings are a bit insufficient.
1. DO NOT USE standard rubber covered plyers on a high voltage capacitor. If it is charged, they may not protect you. Use voltage rated tools in the range you are working.
2. Be sure the wire you are using is rated for your voltage. It is tougher to find wire that is rated above 600V. If you are using 2400VAC, the 600V casing can fail.
I would like to see the plant in a few days. To verify the death and dismemberment.
It is most likely doing a lot of damage to the root system since the grounding stake has been buiried. However a plant with a large root system might only be burned in a few places with the high voltage only following the shortest path.
Just my 2c, I agree this is a very potentially lethal project do to the current/voltage levels, but it’s this kind of stuff that keeps most people (me anyway) visiting HAD. If they start featuring johnny making a blinking LED with a pair of AA’s because it’s safe and there is no risk, what is the point? I know I wouldn’t be back… Safety disclaimers in the writeup are fair enough, but the safety Nazi’s need to go somewhere else.
A microwave oven transformer is capable of putting out 2400 volts at over 1/2 amp.
This will kill you dead, dead, dead.
At least you have a fighting chance with a neon sign transformer.
So is this guy going to make new videos for hackaday ?
I love that he doesn’t edit out the mistakes or failures.
Love the vids man !
Ok, I’m not trying to be mean but this is the second video by Jack that I have seriously wondered if he knew what he was doing. I’m sure part of it is being nervous in front of a camera but there are some factual and safety concerns that are more important. I literally cringed when he instructed us to discharge the capacitor by shorting it with a HANDHELD piece of METAL! No, No, No and NO! The safe and correct way to discharge any capacitor is to put a VERY large value resistor across it and WAIT until you see the voltage on a multimeter measuring across the resistor drop to zero. Even a small cap can arc weld/blow chunks of metal out of screwdrivers, pliers, etc. I’ve personally done it a bunch of times. Fun? yes. Safe? not really. Good for the capacitor? definitely not.
If there are errors in a given scene, please reshoot the scene instead of leaving it in. Even if you have to explain why the wire is already cut and stripped.
That are paying him near nothing. This is why they could only afford a n00b who has no experience in front of a camera.
Dont you remember when they posted the job, The salary offered is peanuts.
The disclaimers are correct, but judging by the execution of the project I’d say the warning are primarily meant for people like the presenter.
I’m all for happy go lucky duct-tape hi voltage hacks, but not here.
The number of mistakes and bad ideas stack up only in comparison to the number of awkwardly constructed sentences by our host. Not a joy to watch while speaking.
u may start fires with that!!!!
MOT shocks suck. Left a scar on my knuckle where the spark ablated a hole.
If they don’t do it here, then they’ll do it after watching Jackass, The Movie. They already have their own parents, they don’t need any more. Life sucks, get a helmet.
We need comment ratings on here so the rubbish and repetitive comments can float to the bottom.
I’m also unsure how something rated as “Dangerous” with a constant warning on it can be considered “intermediate” level. Surely you need a separate “Do not do this” level instead?
Also, don’t tell us to do dangerous things carefully. If you’re ignorant of the risks, you have no idea what “careful” means. It’s kind of hard to carefully electrocute yourself by touching something you never knew was live…
I’m all for weeding out the idiots who can’t weigh up risks themselves though. If you zap yourself and survive, you’ll have learnt a vital lesson about electricity – meaning you can do it again more safely ;-)
You can zap yourself again more safely? :)
yes with one arm behind your back to prevent your heart being in the path back to ground..
Let’s get some info on the robotic weed remover!
The whole video was too timid when it came to working with the high voltage.
At the same time, they really weren’t being that safe. The extra wire he attached looked way too thin – probably rated for only like 600V. At that voltage, they ought to be using wire with thicker insulation – or cover the WHOLE wire with that silicon casing.
I repair microwaves, I took classes with specific manufacturers to learn the ins and outs of them. The only ones who should consider doing this are those who, like me, took classes on microwaves.
They can and will kill you, it can and will probably throw you into the opposing wall, you will probably not feel a thing as it just turns your brain off.
Please do not attempt.
Sorry but I can’t resist commenting here.
This is a project where you miswire a tap on the high voltage end of a microwave and use it to
slightly burnkilllandscaping plantsweeds after carefully describing how to defeat all of the safety measures without describing any of the hazards (eg. instant cataracts from playing with the magnetron)?Dangerous is good, hacks are good, but quality control, editing and useful descriptions are better. Oh, and results are good too. What happened to the plant?
I’m a great fan of Hackaday but this wasn’t very good, I’m afraid.
oh bs… I never took classes on microwaves and i have rebuilt many, know intimately how they work and even hacked a few into one working one. One of which is in my kitchen still to this day I went to school for electronic engineering yes but none the less i was building tesla coils with the very same microwave transformers long before i stepped foot in any college classroom. I dont care how many classes one takes on microwave ovens since in the end it comes down to intelligence and common sense. And ps when working with high voltage always do so with one hand behind your back that way you are less likely to short the voltge in a direct path through you heart.
Are you kidding! I love the disclaimers. Nothing translates clearer to “Do this at home”
and yet you print the article knowing full well
that these disclaimers are going to be ignored.
I have a couple of quite large neon sign transformers, and a vegetable garden which I loathe to pluck the weeds from.
In one area of the garden are already driven a cluster of copper-clad iron ground rods, from eons of incremental telephone service (it’s a very old house). It would be handy to use one or more of these to tie one leg of the secondary to.
My question for HaD: Shall I disconnect or bypass these rods from the telephone demarc, and the 6 AWG bond I have installed from there to the main service ground, or shall I leave the whole thing intact during the weed-killing experiment?
Intuition says that no meaningful current shall flow through my existing (above ground) ground network if I just leave it alone, and things will work fine. And that even if it did flow, it would only be flowing from ground to ground and never through (eg) my household gear.
Intuition also says that if I just poke a metal rod into the ground, ala the video, it will work just as well and be rather well isolated from the other stuff I have going on.
But what does HaD say?
well HaD isn’t going to tell you a thing otherwise they could open themselves up to litigation but ill tell you that nothing bad will happen except for possibly some interference in your radio or tv but even that is unlikely the only problem is see with the ground rods is that they wont be localized to the plant and I doubt will have the desired effect on the root systems but really idk I’m not a eed electrocutioner try it and let us know oh and the standard disclaimer.. do it at your own risk
i believe this method could work.
i accidentally tazed my friend cactus with ONE spark and the ENTIRE thing lost its needles and died with in 48 hours, never to be alive again.
This is so dumb. not only will it not kill weeds but it could kill you.
To kill weeds all you need is some 10% nitric acid in a spray bottle.
I enjoyed this!
But. Whilst I liked how you showed us your method with all of it’s mistakes, you didn’t clearly include any corrections. You’ve basically told everyone how to do it wrong, then shown it working properly.
Considering the danger involved, I think you should be more explicit, rather than constantly warning us.
Best line I’ve read in a long time:
Oh, boy. Why the hell would anyone go to the bother of building this (even assuming the so-called Mr. Buffington knew what the hell he was talking about) when you can buy RoundUp at the hardware store for $15/gallon or so?
Not to mention the Tv-B-Gone problem of screwing around with property that ain’t yours.
My wife owns a 40 acre campground. We use herbicides and mechanical weedwhackers all season long and if something even remotely like this were practical- we’d be using it! Propane burners do get used by us in areas we have water for fire supression. But- the roots are sadly not touched, let alone torched. It’s a nice fictional hack to Tesla Fry Dandelions etc. But IRL- It’s a fail.
The Original Hack does deserve it’s own category of “Lateral Thinking” points in the William Gibson sense.
RE: Safety as a basic concept WrT this Hack alone..
Knowing the risk factors is step zero. USING that information is the life-or death pass/fail exercise in Darwin’s Real Life Testing School.
So- Our Original Hack’s creator has -so far- Defied Darwin. Maybe that’s “Good Enough” for some? Being at the EE levels of calculating lethality potentials Vs having enough basic tech skills to not die from accidents might be part of HaD’s readership falls into. At or above basic but not all EE?
The closing for now comment to me goes to an evaluation of “how” one might really be effective@ electrial Herbicide. Exploit the failure modes of a plant under electrical attack. Ohmic heating by huge currents? Alternated with zapping root hairs by skin effects going up to RF even?
Or= electromigration of copper ions. Copper’s expensive but effective as a foliage slayer. Copper rod drives into root ball- electromigrates into root mass/root>plant juncture? Hmn- testing these ideas by discussing them around a plant wired up for testing the Bose-Backster effect?