Mini High Voltage Jacob's Ladder

Intro: Mini High Voltage Jacob's Ladder

Today's build is really simple but really cool looking miniature high voltage Jacob's ladder. We assemble "15KV high voltage generator kit", get some basic working principles about Jacob's ladder and maybe some more general tips and tricks.

Heart of the build is cheap 15KV high voltage generator kit, i bought it online for about 1.5.- USD.
Total budget on parts was around 2..3USD :)

You can run it on single 18650 battery but i chose dc jack (At the moment the prices of batteries are too high).

Caution! High voltage can be deadly! This project is not a toy, do not
built his project without prior knowledge of electrical or fire safety. Do not touch or correct output wires while device is powered.

STEP 1: Main Components

High voltage generator kit - Aliexpress
Momentary push button - Aliexpress
DC jack - Aliexpress
Ring Crimp Terminals/Connectors - Aliexpress
Pin Screw Terminal - Aliexpress
Scrapped copper wire
Plastic jar lids
some nuts and bolts

Optional:1Megaohm resistors

STEP 2: ​15KV High Voltage Generator Kit

Assembling this kit is straight forward and simple. Components are marked on PCB, just solder them in their corresponding places. Pay attention to diode polarity, it has band to indicate cathode. It's good to add some thermal paste between transistor and it's heatsink.

In our project we'll replace switch for pin screw terminals, or just solder push button with longer wires so we can mount the button away from PCB.

For this project it's better to have momentary switch instead of latching one, it's safer for Jacob's ladder.

STEP 3: Step-up Transformer

Before soldering remove enamel coating from wire tips. I prefer to carefully scrape it off using knife or sandpaper, but you can use flame from lighter or try using hot soldering iron.
Use the schematics to connect transformer to pcb. At the end secure it to pcb using cable-tie from kit.

Original wires for transformer where too short, so let's add longer wires and add extra ring connectors to the output wires (it's easier assemble/replace/modify project later if needed).

Add wires to DC input/power as well, later we'll connect them to input jack or batteries.

If everything is wired correctly you can test it out, you should see high voltage arcing between output wires. Input voltage: DC 3.7V-4.2V

STEP 4: Enclosure

Good way to utilize plastic lids is to make enclosures for electronics. The thicker the better. I found 2 lids that slide inside each other perfectly and can be friction fit.
Drill holes using schematics for:
push button
dc jack
output wire connectors

STEP 5: Two Vertical Wires - Main Attraction

I soldered ring crimp connectors to the end ow wires. You can alternatively just bend loops using pliers. Using connectors/loops it is easy to attach them using nuts and bolts, later adjustments are easier as well.

Give wires the shape as on schematics. Wires have slight tilt to them, its narrow at the bottom and gets wider at the top. Sometimes it's good to add extra bend at the top to be sure the arc will be terminated.

STEP 6: Final Assembly

Time to put everything together.
* Using m3 screws and bolts connect 2 ladder wires and transformer outputs to enclosure.
* Screw down push button to enclosure and connect to transformer PCB.
* Add DC jack and connect it to transformer pcb input.
* Now fit wires and pcb inside the enclosure and it's ready!

STEP 7: What Is Jacob's Ladder

* High voltage arc is formed between two wires at the closest point.
* Spark ionizes the air around it which becomes conductive and hot.
* Hot, ionized and conductive air raises.
* Arc follows raising conductive ionized air.
* At some point gap Gets too wide and the arc cannot be sustained any more.
* Whole process starts again from narrowest point and so it goes.

STEP 8: Bonus Gabriel Electrode

From bigclivedotcom youtube video i got a good tip how to make ladder more reliable. Just soldered 2 x 1megaohm resistors in series to one of the output ladder wires. It hangs in the air near the narrowest point of two electrodes as shown in the picture.
It helps to jump-start the arc making the whole process more reliable.

Comments

[Aeon Junophor]

Hi!
Building such a small version of a Jacob's ladder was a secret dream of mine for many years.... Now....
I have orderd these kits already to start a steampunked version with an acrylic glass tube around. My question is which length did you chose for the "ladder wires" ?
Thx yours Aeon Junophor

[inspiredStudio]

Hi. I have a tutorial for an even better, easier, and a little bit more powerful version coming soon ;)
Make the wires longer than you need, you can clip them shorter later as you desire.

[RobertW352]

I bought a couple of the 15kv kits - they worked fine for a few minutes then stopped working - fairly sure the transistor blows....I've then tried making one re-using the transformer from the kit with 555 timer driving mosfet - that works but its hard to get the resonance/voltage as high....time for plan C

[inspiredStudio]

I have couple of simpler and powerful versions coming soon. And some even more powerful but more dangerous ones.

[MTKapp27]

I am unable to get a spark on the transformer cables. Can you please look through the images and give me troubleshooting tips? I was a little concerned about my NPN soldering, but I think that is okay. I think I wired the thick/thin transformer wire correctly, but I am not confident...? I bought an adapter so I can switch between 3V and 4.5V. Neither setting does anything. Any guidance is much appreciated.

[VoltageStepUpDreams]

Your wiring for your primary inputs are incorrect , the hole with two wires going into from the primary is incorrect , the wire on the right coming from the far right side of the transformer should be going to the hole on the right , the hole that lines up with it , they layed out the psb to be straightforward as possible , and this is a royal circuit , zero volt switching is done , not a fly back . The primary side of it has the equal amounts windings opposite of each other in direction . And also be good idea to check your diode , if it's installed the opposite way its supposed to be installed then the circuit will not work at all .

[MTKapp27]

I really appreciate you taking a look and helping me!!!
I don't understand what you are saying the correct wiring should be for the 4 Thick/Thin wires?
I read over the first installation note here:https://www.aliexpress.com/item/32968528180.html?s...
but I don't understand what it is saying. I think the language conversion is playing a factor.
Is there anyway you could take my picture and red line it for the correct wiring?

I am fairly confident I have the diode installed correctly.

I actually purchased 2 more boards in case I had bad hardware and/or did a bad soldering job.

[inspiredStudio]

Royal circuit?

[jlewczyk1]

How much current can your power supply provide? I need at upwards of an .5amp at 4.7 volts to get a spark with very little gap between the 2 wires (only a couple of millimeters). I run almost 2amps at 4.7V for good effect on the ladder. Does your transformer "squeal" (something like 8Khz)? Mine does in inverse proportion to the spark (less/no spark means more squeal). Note that if it is squealing and there is no load (no spark) your transformer will get quite hot (150F+). Good luck!!

[MTKapp27]

Thanks for the response!
I don't get ANYTYHING. No spark, squeal, or heat.
It seems like something is shorted, but I don't know what. Another thought is that I wired the transformer incorrectly, but I don't know what I would change. I am unable to understand the warning on the site (bad language conversion): https://www.aliexpress.com/item/32968528180.html?s...
The max output on my adapter is 3amps, but I don't know what I am actually getting. I also tried setting it to 5V too.

[jlewczyk1]

Your transformer wiring appear correct. Nice job soldering!

Double check you assumptions ("all the components work and they are are connected correctly!")

I assume you stripped/scraped off the paint from the copper wires before you soldered? (probably wouldn't have soldered so well if you had not).

Somethings to check
Measure the solder side to be sure you have good connection (not a "cold" joint).

The resistance of the windings is very low, but are not "shorted".
I measure ~0.1 ohm between the center and the outside wire. And ~0.3 ohms between the outside wires.
[thin outside] [center(2 wires)] [thick outside]
<--- 0.1 ohm ----> <--- 0.1 ohm ---->
<-------------------- 0.3 ohm ----------->

You can check your 120 ohm resistor in place with your multimeter.

You could measure the voltage your supply is outputting and the amps being drawn too with your multimeter.

Its a pain, I know., but remove (or somehow "just disconnect 2 leads") of the transistor and check it with your multimeter for short/open.
Same for the diode.

Again, good luck!

[inspiredStudio]

jlewczyk1 had a good answer. You should hear the squeal. Warning on aliexpress is about 12v example. I've built 2 of these ladders, both worked on the first try, and one of them is workin still. I've cranked it to 5v and still works. From your photos it seems, that transformer wires are connected correctly. Maybe recheck all connections?

[talk2bruce]

Great instructable. Nicely done! I built this but the spark isn't climbing more that a few millimeters. I used 16 gauge copper wire and they are in the same pattern as in the instructable. I'm not sure the problem is due to the weather - it's in the 80's with about 45% humidity. Any suggestions on how to troubleshoot this would be greatly appreciated! Thanks!

[inspiredStudio]

Try playing with the gap and the shape of the electrodes. I've had sam problem before, if the gap is too narrow it doe's not rise.

[talk2bruce]

Thanks for the advice. After tweaking the gap and shape, I now have a spark that climbs up!

[RayP1]

Can I ask roughly what gauge is the 'scrapped copper wire'? I have some stuff that would work, but it's got too many kinks. Everything I have that's a smaller gauge wouldn't stand up like that.

[inspiredStudio]

It's 1mm. I’m not sure where i got it, i collect all kinds of wires :D Even my neighbor gave me boxful of wires/chargers etc couple of weeks ago.

[RayP1]

Doh! Thanks much for the reply. I don't know why I was thinking about stranded wire rather than solid core 'hookup' wire.

[kcraske]

Strangely I saw the component on AliExpress only yesterday and wondered about a Jacobs ladder. Now I know it works I'll get one. Always wanted to build one but getting the high voltage transformer now if difficult as the usual way was to use neon sign transformers. These have been replaced with solid state power supplies which do not work in this application.

[inspiredStudio]

I ordered one with 20kv and onw with 60kv, just to test out :)