The War Globe

Military Spending by Andrew Cooke is a neat quick project he created that presents the amount each country spends on their military in a nice globe. The idea is neat, but what's even better is the fact that he has all the source code and instructions on how to make something like this. If you're interested in data visualization, I suggest checking this out:Military Spending Data Visualization Example

Topic by lamedust   |  last reply



What is the scientific principle behind using s plasma globe to light up a matchstick?

Why does a matchstick light up when one places a coin on a plasma globe, uses a paper clip to hover around the coin while holding the matchstick alongside the paper clip? (note the video does not use a matchstick, but it still applies the same concept)

Question by    |  last reply


does anyone have a good idea of how I can make a globe of ice - ie. representing the earth, for a photography project?

I want to make a globe/ sphere that looks like the earth (maybe with some colours or even textures) and it does not have to be accurate, just representative. I want to take a photo of this ice-ball melting for a photography project Any cool ideas on how I can make the globe? PS: I dont have an enormous freezer!!!

Question by sParekh   |  last reply


How could one project an image from inside a sphere on to its surface?

I want to make a bad-ass globe, but don't even know where to begin.

Question by TolkienCartographer   |  last reply


Transparent plastic hemisphere? Answered

I've an idea for a project which will need a transparent plastic hemisphere, around 3" to 4" diameter, to house it. Any ideas where I could find something suitable? What would do the job is one of the clear balls from arcade crane grab machines, but I'm looking for something less down to skill, judgement and how much they've rigged the machine.

Question by AndyGadget   |  last reply


can a plasma globe that requires 12 volts and 500 mAmps be put to 12 volts and 12 Amps?

I have a project idea and need this information before starting.

Question by katman101   |  last reply


How to make a Plasma Globe from a lightbulb without rewinding the flyback? Answered

Hi, I noticed that on here: https://www.instructables.com/id/Make-a-Plasma-Globe-out-of-a-Light-Bulb/, You have to rewind the flyback. How could this be accomplished without doing that? Thanks!

Question by Laserbeamtoast   |  last reply


How to make a tesla coil from a plasma globe.?

Is it possible and if so how do you make it?

Question by LaxLuvr   |  last reply


Usb eMail indicator?

Hi, I am looking for a no circit( or chippy thing) usb diy eMail indicator. I would like it to light up a led and ring a bell.

Question by Warlrosity 


Anyone wired up a ready-made multiple-LED globe?

I got a pair of these E10 6xLED globes. I basically wanna use these ones to replace some altar lamps I have which use normal E12 bulbs and keep blowing within a month or so of usage. They are lit pretty much 24/7. Has anyone had any experience in wiring up ready-made globes like these successfully. Are there any resistors inside these globes? Here's a link of the spec sheet availablehttp://www.jaycar.com.au/products_uploaded/ZD0300_data_sheet.pdfAny help would be greatly appreciated.Cheers,Teo

Topic by T e o 


i need a lightning globe can anyone help me?

One without a light bulb and one thats easy to make

Question by odellcowgirl   |  last reply


Xenon flash tubes, xenon arc lamps, and HID lamps? Answered

What are the differences between a xenon  flash tube, a xenon arc lamp, and a HID lamp? Can you turn a xenon flash tube on continuously (or pulsing fast enough so it looks like it is turned on continuously)? How? And what kind of power would it use? I am planning to make a cheap sort of torch with this. How efficient and complicated would it be, and how much light would it produce?                     Answers to any one or more of these questions are greatly appreciated                                                                                                                                        Thanks.

Question by .Unknown.   |  last reply


What is the relationship between the range of an electromagnet and its shape/size?

I'm thinking of building a floating globe sort of thing. How do I determine what size of electromagnet I should build? The globe itself would be fairly light, so the strength at range would not be much of an issue.

Question by MaximY   |  last reply


LED vs Incandescent?

Is it just me, or do incandescent torches generally have more throw than LED ones with the same power?             P.S : I recently found a 3V, 0.3A xenon torch globe. Would you say that it would be brighter than a 2.4V 0.7A torch globe if they are both run off 2 AA batteries? 

Question by .Unknown.   |  last reply


High voltage lamp driver

I have a high voltage lamp driver that i took out of an old projector, I want to know if i wil be able to make a jacobs ladder or plasma globe with it? It supplies 25kv or 12.5kv on each of the two wires? it was used to power the lamp of the projector and it connected directly with the lamp wires. PLEASE HELP!

Topic by Francoisler 


Magnetic Levitation (without electromagnet above, or spinning top)? Answered

Hey, so I was watching some of these videos about magnetic levitation, and I notices that some levitating globes don't have an electromagnet above the globe. Nor is the globe spinning very fast. This is one of the devices that I have seen, and I would like to know how it works so that I can build it....and maybe make an instructable along the way. Also, SimerLab has the levitation down pretty well. Anyone have any ideas? Thanks! Sam P.S. Found another good website here that has one taken apart (it was a Levitron AG). And this website has a kinda breakdown on how one might work, but it definitly isn't specific enought o build one.

Question by samr37l   |  last reply


Will a High voltage power supply from a old projector work to power a Jacobs ladder Answered

I have a high voltage lamp driver that i took out of an old projector, I want to know if i wil be able to make a jacobs ladder or plasma globe with it? It supplies 25kv or 12.5kv on each of the two wires? it was used to power the lamp of the projector and it connected directly with the lamp wires. PLEASE HELP!

Question by Francoisler   |  last reply


12 volt incubator circuit

I need to build a dc circuit which will maintain a certain temperature using a globe as the heat source for the purpose of making a small incubator.?

Question by gozitano   |  last reply


What resistor for 12v HID?

How do I create a cheap " ballast" for an hid globe in my boat. 12v static and whilst charged by outboard stator.  Do I need one? 

Question by gordyguy   |  last reply


High Energy shenanigans

Blowin up small fruits with my capacitor bank, and a little look at my homemade plasma globe hopefully ill add more of a description at some point, feel free to comment and ask questions

Topic by The 4th Doctor   |  last reply


Google Earth: How to open facing a chosen destination? Answered

Google earth opens with the globe turning to face the USA. I would prefer changing this to Europe, or when on vacation, to face my temporary location.  Is this possible?

Question by BobS   |  last reply


Is a transformer that puts out 12VAC at 2.4 amps safe to use with a circuit that only draws 0.58amps? Answered

The circuit i attempting to drive is one from a plasma globe. I was not sure if the excess output of the transformer would "fry" components on the board

Question by firemanfu   |  last reply


Where can I get a plasma ball driver circuit? Answered

I have a old glass sphere from a plasma globe and I was wanting to use  again but i need the circuit I need it if I want to use it again

Question by nerd7473   |  last reply


how to independently light up a 4" model street lamp?

Light-up model street lamp, 4" tall, 14v.i need to be able to light it up without a model train power converter. 

Question by leahthepeach   |  last reply


Can I make from an taken-out plasma-ball an plasma-speaker?

I have take out the glass-globe with the gas from my plasma-ball. Can I make it to an plasma-speaker? p.s. i'm from germany, so i apologize for mistakes ;-)

Question by Gujkil   |  last reply


Plasma ball with Giant vodka Bottle?

Hi I am thinking of using a Giant 3 litre Smirnoff vodka bottle  as shown in the link below: http://www.licorea.com/smirnoff-3-litros-dosificador-p-809.html?language= To make a Plasma globe but inside the bottle. I need some sort of high voltage supply and an electrode but aren't sure what else . The main Problem I can see is creating a vacuum inside the bottle . as I don't have a vacuum pump. Does anyone have any tips on how to create a vacuum inside the bottle? Also would an inert gas work instead. Any help appreciated  Thanks Ben

Question by 369ben   |  last reply


What should I do for my science fair

Well, I have to get a science fair project, I am 12, and so is my partner... We need tohave our Hypothesis and Purpose in by November 24th I think. We are thinking about the LIghtning Globe on here, or, another thing called the Kane Effect, or something else, any ideas/

Topic by cutecat13   |  last reply


(newsletter) DIY Book Scanner, $50 Laser Cutter, The Eyewriter

  DIY Book Scanner How to Solder The Eyewriter High Power Head Lamp Make a NES PC Word Clock Typewriter Computer Keyboard $50 Laser Cutter Wifi Range Extender Make Your Own Lightning Globe RC Nerf Tank Guitar Tube Amp Guides LED USB DIY CNC

Topic by fungus amungus   |  last reply


Electric Eel Powers Christmas Tree

Y'know, I've always wondered about this. An aquarium filled with exotic fish here is using an electric eel to power lights on a Christmas tree.Each time the electric eel at the Aqua Toto Gifu aquarium touches a copper wire in its tank, it sends power that lights up globes decking a Christmas tree.From the Mainichi Daily News. Can't get the link to work to verify, so possibly a hoax.

Topic by fungus amungus   |  last reply


How difficult is it to Increase the intensity of a plasma ball?

I just bought a cheap USB (5v) plasma ball. Quite frankly, the intensity of the streams is pathetic. You can barely see it when the lights are on. I wanted to use it for a decorative project, but need to increase the intensity of the streams. Would increasing the voltage (say from 5v to 12v) work? Or is it more complicated than that? I can do basic electronics, but mostly just simple stuff following circuit diagrams etc.

Question by Beenay25   |  last reply


CFL's putting out too much UV radiation?

Our local (I think) news service has done a story about CFL's emitting too much UV radiation, You can view it here.Would you rather sit under an incandescent light or a CFL for a extended period of time?Do you think they should have warning labels on them?Do you have any other opinions on CFL's and energy saving globes?Or do you think this is all just a way to get more people to but the old incandescent bulbs?

Topic by thermoelectric   |  last reply


How to run a mini halogen light from the mains? Answered

Hi all, I am working on a project and need to run a mini (35mm) halogen globe from the mains.  I live in Australia and our  mains from off 24v.   If I try and run the halogen it works ok but soon heats-up a lot.  I'm assuming that I need a transformer to reduce the voltage or amperage but cant find anything on the net!  I want to run the lamp that I am building direct from the AC socket.  Does anyone have any solutions?  I have also looked at 12v LED ones as well and thought that this might be the best path to go down.   Thanks, Marcus

Question by lonesoulsurfer   |  last reply


Incandescent to LED torch mod? Answered

All the LEDs I have seem to have not so good throw. (Even my 3 watt luxeon is outmatched in throw by a 1.2-ish watt incandescent  torch), so I was wondering how I coud increase an LED's throw. I noticed that the light from the globe was not very bright, but seeing as how it throws light in all different directions, it probably gave off just as much, if not more, light; probably why the reflector was there. So I figured that if I got a bunch of LEDs, then put them into a torch, pointing them to the side at the reflector, the throw of the light would be greater than if I just pointed the LEDs forward, right?

Question by .Unknown.   |  last reply


Stun Gun Mod Suggestions/Tips? HV Power!

The 2 images are the type of stun gun parts I have, I believe its a spark gap igniter one but m not 100% on that as I would rather leave it in the cardboard circular case unless I get confirmation it could be modified. What kinds of projects could this be used for, I'm pretty sure its DC powered and attempted putting the outputs to curved metal electrodes for a Jacobs ladder but arc stays in one spot after many adjustments.  Ive only worked with HVAC with an unrectified flyback for plasma globes. Anyone have any suggestions on what to pump this badboy into. P.S. Using 2 metal screws from an Xbox 360 and putting them very close together makes a very nice whistle to it, :).

Topic by thebellbell 


Netboot server will not allow me to pull images nor save client data to raid storage on server, does anyone know why?

I have a Mac OS x Server 10.5.6, dual 2.3GHz PowerPC G5 8 GB Ram, i have setup server admin on this machine however, I am wanting to use this for specifically as my netboot server, i have created the images and when i put them on this devices internal hardrive, everything works just fine but when i move them over to the raid storage i have set up, Server Admin recognizes the images and allows me to enable them and also make them the default images however when i actually try to netboot a machine, i get the Grey Screen of Death, I see the globe spin shortly then the grey screen populates the screen and i see a bunch of different languages on the machine then i have to reboot to get rid of this screen... How do i make my netboot server be able to serve these images and save the client data to the raid storage???

Question by enixw 


LED Spidies- Craft for Kids. On Sale Now. Limited Offer

Have a spare weekend coming up and not sure to do with the kids? Bored of the normal electrical kits supplied at stores? Want a novel activity that will give you time to bond and create something with your child?Seen my LED Spidies but don't want to get the materials? Craftzine Halloween blogLED Spidies Instructable StepsLED Spider kits are now available for a limited time.What is included in the kit?~ Pre-cut preformed lengths of wire~ Two HI LED globes~ Circuit wire~ Body for spider~ Assembly instructions via link to InstructableCan I assemble it myself?Not only can you assemble it, your kids can too. Due to the simple nature of the circuit, anyone can create it with minimal effort.But won't it be finished quickly?No. LED spiders can take as long as you like, the decoration is half the fun.Cost of unitsLED Spidies kits are available for $12.50USDiscounts apply for bulk purchases.For purchasing enquires or further information please contact me. Lefindoubt@Hotmail.com

Topic by Lftndbt   |  last reply


Insanely Cool Multitouch

So now all I need is $100k and I'm ready to rock. watch the videoJefferson Y. Han likes big computer monitors. If a screen is large enough, four or five people can work at it together, rearranging blueprints, say, or editing photos. But they can't do that if they're taking turns at a keyboard and mouse. The answer, which Han demonstrates on a 3 x 8-ft. monitor in his lab at New York University, is multitouch input. It allows any number of users to lay hands on the screen as if they were manipulating real objects. On the monitor, recently dubbed the Media Wall, Han uses his hands to spin a virtual globe and then zoom into the canyons of Manhattan. "A mouse is an indirect pointing device," Han says. "You're working with an object that's not on the screen. Multitouch computing is direct manipulation."Han, the son of Korean immigrants, drew inspiration from the way light diffuses when you touch a glass of water. It's a phenomenon known as "œfrustrated total internal reflection." Han attached LEDs to the side of a piece of clear acrylic ”his screen" and mounted an infrared camera on the back. Light traveled through the acrylic. When Han touched the screen, some light diffused out and was captured by the camera. He then designed software that allows the screen to be used for operating mapping programs, handling photos and drawing animated figures. Perceptive Pixel, the business Han started with an NYU colleague, builds custom multitouch computers for private industry and military clients (and, now, to anyone with $100,000).Multitouch computing isn't new: the concept has been kicking around since the 1980s, and two Breakthrough Award-winning products, Apple's iPhone and Microsoft's Surface, use versions of it. Han's special contribution: Beyond his varied applications for multitouch computing lies a broad vision of how it can empower people to work together in new ways.

Topic by fungus amungus   |  last reply


Salami Fridge/ Fermentation Chamber

I am trying to set up a salami / prosciutto fridge at home. This is good for everybody haha.FYISalami needs certain parameters to correctly culture and age.Day1 22-24C 95% Humidity Day2 18-20C 90% Humidity Day3 16-18C 85% Humidity Day4 14-16C 80% Humidity Day5 12-14C 80% HumidityDay6 12-14C 75% Humidity Day7 10-12C 75% Humidity To Age 10-12C 75% Humidity I have-a domestic fridge which I have cut and fitted an exhaust fan in the front a humidifier a light globe (for warming) a grey electrical box – holes cut and 4 single power points fitted.a Lcd display and control board (from Jaycar) for the arduinowhat it needs to do is the following I want the control panel to have, temp control, humidity control, I want the exhaust fan to run 1min every 4 hours – this is because ammonia builds up as a gas in the chamber, this needs to be removed via the attached fanI want the humidifier, the light and the fridge to be controlled by the same “temp” control; Ie Day1I set the fridge to 95% humidity and 24CLight on to temp then off - or on/off as needed Humidifier on to correct parameters then off - or on/off as neededExhaust fan comes on and the computer compensates this evacuation and temp/humidity is onDay2I set the fridge to 90% humidity and 22CLight on to temp (or fridge cooling, depending on temp)Humidifier on to correct parameters Exhaust fan comes on and the computer compensates this evacuation and temp/humidity is onEtc.. etc..etcNow this also means this needs to be adjustable via the little control box because some thicker sausage takes longer and thinner less… ie Humidity1=95%H 2=90%H 3=85%H 4=80%H 5=75%Htemp1=24C 2=22C 3=20C 4=18C 5=16C 6=14C 7=12C 8=10CAnddddd prosciutto doesn’t need this type temp/humidity drop. It only needs a stable 75% humidity and 12CThe idea is Ill have a sparkey wire up plugs into the humidifier, light, fan and fridge.. they all plug into my super sexy grey box that has 4 plug holes on it ( ill send you pictures)..The inside of the box - a 4 switch relay... to power the toys a connection and lead in that gives power…. And I have access to the liitle LCD screen to adjust the parameters when needed.I assume I need to get more electrical/computer parts for this.. and the program written that controls all this info.any info will be rewarded with salami.!!!!!!!

Question by BojanG4 


Hey, let's invent this immediately!!!

OK folks, how hard can this possibly be?Yeah, yeah, I know. Probably REALLY hard. But if we all team up and combine our gray matter, can't we overcome any technological obstacle with our collective geekiness?I want to see an affordable, open-source doodad that can turn an LCD from a dead laptop into a working external flatscreen monitor. It should accept digital & analog signals and allow us all to hack up beautiful screens ready to embed in our brilliant projects, while keeping LCD's out of the landfill.punish3r valiantly went down this road: https://www.instructables.com/id/Laptop-Converted-to-2nd-Monitor/but then ended up "cheating" (his words, not mine) by using software that does most of the work (plus he started with a functional laptop!). Discussions I've read usually end with "you'd have to buy a controller for that specific LCD, which would cost almost as much as a regular flatscreen so what's the point?"I reject this (resting on my laurels of ignorance)! If a controller truly exists for every LCD on earth, don't they share lots of common features? And if so, can't we come up with a generic one that could be programmed or dip-switched or soldered or otherwise persuaded to play nice with any LCD on the playground? Even the weird one by the monkey bars who smells like cheese? (Sorry; stretched my metaphor too far and it broke)I envision a circuit board with PC or even TV "in," an amazingly versatile multi-pin adaptor or cable that would replace or connect to that flimsy little ribbon cable sprouting from the LCD. The board would have a USB plug for programming, and a chip smart enough to remember what you tell it. Some smart person will write a nifty app that talks to the board, and vast legions of techies across the globe (or rogue employees of the LCD manufacturers, perhaps?) will upload specs for all of their LCD panels that will be used by other smart people to create a profile for any given panel that can be dropped onto the board.It would have to be really low-cost to make sense, but I envision a cottage industry: package it up as a kit, or we could build goofy-looking monitors out of e-waste and sell them!Somebody else could probably strengthen the argument in favor of this invention by providing a list of terrible LCD ingredients that would be re-purposed out of our trash heaps and water supplies and cat food... I'll leave that up to the experts.What do you think, folks? Is this a pipe dream, or a viable idea? Either way, let's do it!(and if anybody manages to make one, I get dibs on a prototype!)Thanks for reading!Mike

Topic by mikecraghead   |  last reply


BJT vs MOSFET? Answered

-- background: In my perpetual pursuit for designing the best, cheapest, & best performing flyback (line transformer) driver, I've decided to try out some big BJTs, which appear to have higher voltage & current ratings @ considerably lower cost. In the past, I have tried MJE3055's, which work OK, and allow the generation of thin blue arcs from a 12V supply for a few minutes until the transistor dies due to high voltage kickback or overheating. The FDP33N25 gives good results but is somewhat unreliable at 24V. So I decided to give these alluring "PHE13009" 400V 12A rated NPN BJT's a try. However driving the transistor adequately seems to be the problem. (I didn't realize these transistors would require like 5A base current w/ only HFe of 2!) It seems like almost all the "good" driver schematics utilize large $$$ FETs or even IGBTs, but almost every CRT, plasma globe, and ballast (SMPS) I took apart seem to prefer high power BJTs probably due to this exact cost difference. I was only able to get simalar performance to my 33N25 MOSFET when I stuck an additional TIP120 in as an additional darlington stage, which worked very nicely (white hot arcs) for about 1 second, then it popped! :( Since the collectors are tied together they are all exposed to >200V transients, I am sure that's what killed it. I substituted that transistor for another PHE13009 to see what would happen and with a third driving stage (2N2222) I could get somewhat acceptable results but I know I can do better. >:) - My actual questions:  * The GDP of this transistor is 40MHz, seems fast to me. (certainly faster than the 2MHz GDP of the 2N3055 which works well in my slayer exciter.) and MOSFETs have significant gate charge. ECE2630 glossed over transistors mentioning BJTs are faster, (small signal ones, anyway :P ) and some internet sources agree, but I am finding lots of sources saying the opposite! What's the deal? Which one "faster?"  * How to traditional BJTs compare to IBGTs? Which are faster/better? The datasheet for this transistor explicitly mentions its use for "high frequency ballast and switch mode applications" which implies that it is well suited for my needs. It also includes a several inductor test circuits, but other than that the datasheet is pretty bare-bones.  I'm actually a little disappointed the HFe is so low (around 2-3) @ >10A. I may require more windings on my primary and a 48v supply. (not ideal) * I know I will dissipate a little more heat due to the base current, and something I didn't consider was heat dissipated in the resistor biasing/controlling the base. (like 12V at several amps just to drive the damn thing!!) so it is worth the cost benefit of $0.5? Is there a configuration I could use that makes driving the transistor easier?

Question by -max-   |  last reply


Universal ultrasonic driver circuit - help required

I would like to build a few, properly working, ultrasonic devices.For example an ultrasonic soldering iron and an ultrasonic soldering bath.But some small ultrasonic plastic welder or cutter is nice too :)If you ever had one of the above to play with you know why they are great to have.The development story so far:I managed to destroy several driver boards.The ones you find for cheap with 28 or40kHz transducers in your favourite online store.In the beginning I knew I will have a need to repair or replace these boards but no clue why.Take an ultrasonic cleaner and read the manual.There it is always pointed out that a low water level can destroy your toy.What does that exactly mean?The transducer needs to be kept in resonance, if the water level is too low or something havy sits right at the bottom of the tank the frequency drifts off too much.Very expensive untis can cope a bit better here, which gave me the idea for the universal driver.During my experiments with hoorns I noticed that it is very hard to get usable results without extensive computer simulations first.Just one mm too long or too short and literally nothing happens, go a bit further and a thin aluminium horn might start to crack under the stress.And in all these cases the driver overloads, in one cheap case to the point that the transducer fused together.Trying to examine these driver circuits while they operate turned out to be a total nightmare!Place the probe from the ocsilloscope literally anywhere and the thing goes out of tune already.By the way: Never coil up the wires going to your transducer.....Only way I found that somehow works is by adding a tiny transformer around the wire going to the transducer and to measure the voltage generated there.To make it short: Destructive testing provided the requirements a driver needs to match to keep the cost low.Reasons for the premature death of cheap driver boards:Almost all of these cheap drivers I could find generate the 28 or 40kHz signal from the mains voltage.Means it goes through a transformer to get the desired 50-80V and some witchcraft turns that into a more or less smooth DC voltage.This is then switched by some beefy transistors, mosfets or similar, depending on the circuit.The actual feedback happens with a tiny ring toroid, similar to what you use to drive a ZVS system.With this dirt simple design a fully tuned transducer - like when nothing is attached to it yet - would cause the driver to provide a voltage of about 6x of what the transducer is rated for.Thankfully in most cases the transducer survives this a couple of times while the transistors fry within about 3 seconds no matter how good the cooling.Slightly out of tune - like when mounted onto a cleaning tank - the resonant frequency is slightly off the tuned 28 or 40kHz.The driver compensates this through the tiny feedback transformer.But this only goes for a about 1-4kHz, drift away further and first the power drops, then the voltage spikes and it dies.The feedback is not able to shift the generated frequency enough as it is ultimately derived from the mains frequency of your grid.Reasons why a dedicated, low cost driver would open new possibilities:Imagine you need to make a horn or sonotrode for your transducer.Knowing that each half of it should be equal to a quarter wavelength of the operating frequency is nice and easy.But if you add something like a blade for cutting or you need some pressure for welding then calculated dimensions become useless.Programs to fully simulate complex sonotrode designs, especially if you need to add screws or blades are costly and out of reach for most of us.Even if you would have access you still need to know the material properties to know the speed of sound in the material and how much it can flex in various directions without being subjected to metal fatigue.For basically all hobby needs in terms of ultrasonic gadgets we are happy with a simple push pull motion.the same motion our transducer offers by default.And when it comes to attachments it turned out that quite stubby horns of light weight are a good compromise already.A 50-50 ratio of diameter and length works reasonably well in most cases.For example the standard 40kHz transducer of 45mm diameter is quite happy to work with a horn like this:45mm diameter on the thick end, 20mm diameter on the tin end.Thick part 40mm long, thin part 42mm long.The extra 2mm are for the manual tuning by filing or sanding it off until there is good cavitation happening when you put the end into water.This however is only good for simple testing purposes and some fun but as soon as you attach blades or a small pot with about 200grams of molten solder the tuning is way off and destroys the driver quickly.To be able to deal with different pressure levels on the working end or just a different mass that is attached the driver needs to "know" the new self resonant frequency.Basic idea for a dedicated driver:Please bare with me on this one as my developing days got severly neglected once I moved to the other side of the globe....Input should from a 12V power supply, preferably a PSU to keep costs and sourcing time low.The operating voltage for the transducer shall come from a simple switch mode supply.I was thinking of scrapping a PSU for the transformer and switching transistor.This however would provide about 120-160V on 240V mains with the transformer of a PSU.To match the required load changes it would be great to drive this first transformer by PWM means to regulate the output voltage with a potentiometer while keeping it steady within the set values.Basically like every cheap phone charger but with an output voltage that can be adjusted and kept regulated.The switching transistors for the transducer should be well over the required specs of an out of tune transducer.I guess capable of switching 600V should be sufficient.Main design change to the cheap driver boards would be the feedback.A hall effect sensor could provide the proportional voltage to the current going into the transducer.It would also provide the real operating frequency of the transducer for the feedback loop.The resulting real resonant frequency of the running system is then used to drive the switching transistors.As a result the transducer would always be driven at the exact right frequency no matter the load on the working end.These transducers still have a quite limited frequncy range due to the fixed counterweight on the back - it is optimised to be self resonant without the transducer being mounted.To explain this feature let me use a spring with a weight on it....You can move your hand up and down to make the weight swing up an down with the spring force.You can also push the weight to get the same effect.But if the weight would just expand and contract there would be no change in the spring force or position or the weight.Our transducer however is mounted to something and the weight on the back is heavier than what is on the front end of the transducer.As a result the weight is pushed back and forth and because all is fixed together this movement is transfered to for example your cleaning bowl.Without anything attached to the transducer it would literally start to rip itself apart until either the bolt or the ceramics fail.The feedback loop needs to prevent this by adjusting the switching voltage going to the transducer.Once too far out the system needs to shut off until it can reset.The frequency control is not that fragile.With the power controlled through the feedback even a wide drift in the operating frequency of about 5kHz would only reduce the effectiveness and amplitude of the moving horn/sonotrode.Sadly my skill set in circuits is not that good anymore to have the required parts in my head and to know how to combine them properly :(Why this concept is only really good for really basic applications:Professional solutions utlise often less than 20W of ultrasonic power for a soldering iron or scaler.For these devices the sonotrode/horn is spefically designed for the task at hand.Same goes for any possible attachments - without them these things don't do much at all.Finding these low power ceramic transducer rings for a good price is hard enough, making an amplifying horn even harder.But when using these quite big 50 or 100W transducers we find for cheap online we can compensate the lower amplitude with the added power of the transducer.Since we only need surface action but won't have to go through a few liters of liquid it might even be beneficial.Fun fact: A 40kHz transducer has the second harminc frequency at about 170kHz.Means we could design a driver for the second harmonic and enjoy total silence when working with it.Would also mean that the ultrasonic power would be much higher.Mass times acceleration and such things ;)If you want some ultrasonic cutter then you don't want to waste weeks and lots of money trying to come up with a working attachment to your transducer.Just keep it as short as possible and with about the same weight as the front part of the transducer.At least the driver desing would make it quite easy to design an amplifying horn by trail and error through reducing the lenght of the thin end until it really fits.Anyone with good circuit skills willing to volunteer? ;)

Topic by Downunder35m