I like how that MOSFET de-soldered itself for you at 5:39. How convenient. :D
@greatscottlab2 жыл бұрын
That is the thermal protection ;-)
@jkadofo2 жыл бұрын
@@greatscottlab 😂😂😂
@WarriorRev63002 жыл бұрын
@@greatscottlab 🤣
@weitaojiang5772 жыл бұрын
@@greatscottlab lol
@cezarcatalin14062 жыл бұрын
@@greatscottlab I had some 12v led lights that after about 1h of usage they were desoldering themselves and falling on the floor with their 2 legs still holding onto the sockets on the ceiling. It turns out the manufacturers thought it was a good idea to use thin traces on the board as an 10ohm resistor... instead of using an actual 10ohm resistor... On the upside, the manufacturers didn’t specify that if you mount the lights upside down they come with integrated thermal protection.
@MatthewDeveloper2 жыл бұрын
5:39 I believe this is what datasheet's mean with the "Integrated Over-Heating Protection" feature 🙂
@Zebra_Paw2 жыл бұрын
If you look at one specific comment, you can see from GreatScott’s answer that he had the same idea…
@PichanPerkele2 жыл бұрын
I actually used the "bad" HV generator to build an electric wasp swatter. It's ghetto af but wasps literally explode after a few seconds of electro therapy. With 10mm gaps and nothing in between it still arcs loudly all the time. I'm afraid to use it near sensitive electronics but I still love it.
@whimsy56232 жыл бұрын
That's horrifying
@RotaryMarx Жыл бұрын
lets make it
@vke6077 Жыл бұрын
I love that, hahahhaa
@user-no7ki3gc1w4 күн бұрын
ok guess im building that fo mosquitoes
@divingquokka2 жыл бұрын
3:38: "a kit with suitable driver circuits" You mean: a transistor that burns out in minutes.
@greatscottlab2 жыл бұрын
Haha true ;-)
@divingquokka2 жыл бұрын
@@greatscottlab And that was before I had seen the whole video. Two of those circuits dead on my bench.
@cavemaneca2 жыл бұрын
Seems to be designed for a very low duty cycle. Like 5 seconds on 5 minutes off lol
@snaj99892 жыл бұрын
@@divingquokka I also built that same kit before and it only worked for 2 minutes before mysteriously dying. Now I learned why.
@DrakeOola2 жыл бұрын
@@snaj9989 They're not designed to run for more than a minute or two. If you tazer someone longer than that their heart will probably give out. To be fair tho, that's not what any of us use them for and they don't list any warning about that tho... 😅
@Makatea2 жыл бұрын
I think both ways have their merits. Certainly you learn more with a kit (for example that the included transistor is not up to snuff). But for building my gas-stove-igniter I used one of those ready-made modules, an 18650 and a spark plug. It works like a charm and a kit would be very hard to properly isolate. And frankly, I couldn't care less for the PTB-certification, that's just germans being germans for no good reason...
@witchofengineering2 жыл бұрын
Exactly, if you're electronics enthusiast and just want to play around and learn stuff go for the kit, but if you are actually using the HV to do something practical instead of just playing around (f.ex. I also used that module as an igniter), then the module is easier to use, cheaper, better isolated and likely has more resistance to mechanical vibrations and such. And yes, I also used one to make a taser, afaik it's legal in my area edit: of course that doesn't apply in the case where you need some specific voltage / frequency / other properties at the output, then you have to design your circuit anyway
@ianhill201012 жыл бұрын
That spark gap would make a wicked cannon ignitor, rather than spray gas in and hope for a stycometric value to get a good boom 💥 split water with electrolysis to have a perfect ignition everytime.
@TravisFabel2 жыл бұрын
Yeah he sold me on the first one that just worked because I have a propane grill that does not have a electronic igniter on every burner. It only has it on one and that is supposed to light the other burners along the way. I can see how adding this with A small bit of work could make the igniter circuit work on all of the burners
@daviddavidson23572 жыл бұрын
They make for good gas igniters but they also burn out fairly easily if used for a short period of time continuously. Had one in a project box with two bolts coming out as electrodes and a PTM switch to turn it on. Got some big zaps from it though.
@kevinslattery57482 жыл бұрын
👍 for your last sentence!
@nanosyberww48492 жыл бұрын
He’s turning into Mehdi with these projects 😂😂
@Mauricetz2 жыл бұрын
But without beeps haha
@shubhamadtp2 жыл бұрын
No bang shoutinng No
@tylercollins41252 жыл бұрын
Soon he might start blowing up capacitors and touching bare mains wires 😂
@Freddyfanmulti3214 Жыл бұрын
No,he is scared of these arcs mehdi isnt
@Freddyfanmulti3214 Жыл бұрын
Styro isn't scared of them either,he's made arcs bigger than scot and mehdi
@maurice-le-roux2 жыл бұрын
I literally bought 5 of those this week to upgrade some bugswatters for my friends. I will enjoy doing it like your advise in the video. Thank you so much!
@darekmario4462 жыл бұрын
I did the same thing :D
@DrakeOola2 жыл бұрын
Are you putting all 5 into one bug swatter or do you just have 5 friends with a big enough bug problem they need an 'upgraded' bug swatter? 🤨 Bug swatters work fine but the only bug they actually attract or work on here is moths, except a regular light bulb ends up killing them too...
@maurice-le-roux2 жыл бұрын
@@DrakeOola Well it's the handheld bugswatter. I fix those with a rechargable cell with USB connecyor and then with the HV generator. It's mostly fun, very deadly for bugs and my friends love it.
@darekmario4462 жыл бұрын
@@maurice-le-roux I love it, I've actually done this with zvs circuit like great scott, as i Was 14. It was very effective against those little fruit flies that normally flew trhough the flyswatter. But the zvs had to high frequency and melted the flyswatter if you hold it for too long. Those another HV generators are cheap, effective and already prebuild :D
@maurice-le-roux2 жыл бұрын
@@darekmario446 awesome, yes nothing will get past it haha.
@Calthecool2 жыл бұрын
Yeah, I would never buy a single one of those off Amazon. I would buy the 3 pack so I have extras.
@jkadofo2 жыл бұрын
😂😂😂
@greatscottlab2 жыл бұрын
Smart ;-)
@cezarcatalin14062 жыл бұрын
@Joseph Bunn Well, if they are synchronised... can they self-synchronise ?
@cezarcatalin14062 жыл бұрын
Technology Connections: Through the magic of buying 3 of them.
@chrisakaschulbus49032 жыл бұрын
@Joseph Bunn the voltages from those listings are pretty much made up numbers... on ebay you see the same package with all kind of different voltage numbers. 5kv, 15kv, 25kv... they add anything to the description in the pursuit of sales :D
@adityashukla78492 жыл бұрын
Your videos are always perfectly timed. Just got my hands on few small Transformers.
@greatscottlab2 жыл бұрын
Enjoy!
@SkookumChoocher2 жыл бұрын
I like your videos, but I'd say the very beginning is kinda ridiculous. Why the heck should you need a certification for everything? Ugh.
@Ni5ei5 ай бұрын
Not just that. Take a certified lamp holder, plug it in and stick your finger inside. It can kill you! But hey, it's certified so then it's okay 😂
@Rogerfuk5 ай бұрын
Europeans love their certifications
@LiveSeruio2 жыл бұрын
I personally like does little pulse high voltage modules because you can blow tiny holes in paper or leafs and they are pretty loud if you pull contacts far enough so they make a great house alarm
@greatscottlab2 жыл бұрын
That is also an application
@littleshopofelectrons40142 жыл бұрын
Someone in our FB HV group has de-potted one of these to see what's inside. Essentially its a Cockroft-Walton voltage multiplier with several stages. The problem is that there is no current-limiting resistor so the devices eventually fail from diode destruction or over-heating.
@StarCracked2 жыл бұрын
@@littleshopofelectrons4014 so it's best to add a current limiting resistor? What would you recommend?
@littleshopofelectrons40142 жыл бұрын
@@StarCracked HV resistors can be expensive. The resistor(s) may cost more than the module. I believe the output of these is no more than about 50 KV regardless of what the ad says. A few megaohms should be adequate.
@inductivelycoupledplasma6207 Жыл бұрын
@@littleshopofelectrons4014 more like 15kV. I can't imagine the caps inside are rated to that (just little film caps)
@stephenshenenigan35722 жыл бұрын
You should get sponsored by Stabilo. Your hand drawn schematics are fantastic!
@gianluca4582 жыл бұрын
YEEEES!! I HAVE ONE OF THIS TRANSFORMERS LAYING AROUND. PERFECT TIMING!
@kermitdaphrogge5252 жыл бұрын
Be careful around it .
@gianluca4582 жыл бұрын
No problem, i have a diy voltage multiplayer that makes 50KV. Capacitors are very small [47pF]. I have a lot of Experience, aaaalways careful with theese things. But i DIDNT know how to do that with music, i will try to find an ne555 audio modulator for it so that i can build my first plasma speaker!
@greatscottlab2 жыл бұрын
Be careful and have fun :-)
@sgt-Badger2 жыл бұрын
I have a step down transformer, Can I make it?
@ShahZahid2 жыл бұрын
@@sgt-Badger works with flyback step up, idk about step down tho ig ill try it maybe the results will be interesting
@3v0682 жыл бұрын
I have to thank you for making this all about safety. Its a thing that is underrated when it comes to electronics, even small power electronics that dont produce much voltage and amperage. It is appreciated, from a hobby/bedroom electrical engineer.
@greatscottlab2 жыл бұрын
Well said!
@chrisakaschulbus49032 жыл бұрын
but he also sometimes overdoes it... but at least he's not like those youtubers with twenty "do not try this at home"-warnings
@3v0682 жыл бұрын
@@chrisakaschulbus4903 I think it's important he overdoes it. If you think about it, despite it's flaws, our power system in the United States is relatively safe by modern standards even with our plugs. One of the main reasons is we don't like plugging in a ton of things into an outlet which helps prevent electrical fires as we don't have much safety from the plug, onwards outside of your wall.
@vylbird80142 жыл бұрын
I got one of those devices years ago. Clearly the same thing, but mine was promoted as a component for oil-fueled boilers - the ignition spark generator.
@tamzidhimel2 жыл бұрын
I was thinking what to do with those small transformers. Thank you for this video .it helped me a lot
@greatscottlab2 жыл бұрын
You’re welcome 😊
@m.luthfi.alhadi2 жыл бұрын
In some country, that first HV generator is used for making stun gun/taser and it is sold everywhere. I have one of it to make my own taser for self-defense. Because in my place, robber sometimes kills the vicitm. sorry for my bad english
@Hessijames792 жыл бұрын
So basically your recommendation is not to use the working Amazon modules but rather solder up a kit that rapidly transforms in a completely safe HV generator, i. e. a broken one.
@E-BikingAdventures Жыл бұрын
That transformer is not wound at a ratio of 1:3750. It's somewhere around 1:100 - 1:200. It uses inductive spiking on the primary to 'boost' the voltage. Do you not recognise a boost or joule thief circuit when you see one?
@raisagorbachov2 жыл бұрын
That little HV generator looked a good idea, honestly. Imagine for a moment you wanted to do high-speed photography. A brief arc of light from high-voltage coils is how that is done. Ordinary xenon flash tube max out at 100,000th of a second due to the latancy of xenon. With an air-gap flash you can achieve 1,000,000th of a second exposures.
@MRFIRE-cw6hp9 ай бұрын
and you can use it for cheap edm machining!
@PurityVendetta2 жыл бұрын
I used one of those eBay things as a spark igniter in my engineering workshop. For the price I couldn't beat it but I get what you're saying as I also love to build things for fun and experimentation.
@shinrakishitani10792 жыл бұрын
I managed to shock myself with the black one, from that I can tell you it's more like a stun gun than a taser, still hurts like hell though and since it locked the muscles in my arms, pretty dangerous too. That said the other small one you showed is incredibly fragile, I had two one of which broke because of the thin and fragile ferrite core, and the other one had the insulation fail after a few seconds of the high voltage leads being too far apart, not worth your money either. Better do some research and make/get a good Tesla coil
@Vizi_2 жыл бұрын
i've build 500kV Marks Generator with this. 50 cm sparks kick ass
@DepressedMusicEnjoyer Жыл бұрын
I have shocked myself with the black one couple of times and it usually wasn’t too bad, way better than electric fence
@idontsleepidream2 жыл бұрын
Man. I have to tell you how much I have enjoyed watching your videos! The pandemic open my eyes to discover a passion that I never knew existed. I am a straight up newbie... completely green to electronics. Not new to coding, so that helped me out... thank goodness. And I am a practicing electrician, in the US. I just love that you explain everything so well. I love that you break everything down practically. I also love that you have the belief that sharing knowledge is awesome. And your schematics are DOPE! Thank you for what you do! I am really enjoying my new hobby... that might be opening up some career moves...?... 💙💙💙
@RoyalTech_20242 жыл бұрын
Hi Great Scott, good video. Yes you said it with high frequencies we don't get shock but burns the skin. This is the technology used in surgical diathermy machines used in all kinds of surgeries in operation theatres. They used to cut, coagulate and do other porcedures on human body. Used in almost all surgeries like gynaec, general, eye, skin, uro, etc...
@jkadofo2 жыл бұрын
Thanks for the info 👍🏾
@RoyalTech_20242 жыл бұрын
@@jkadofo 👍
@ANANTHASANKAR_UA2 жыл бұрын
Im Assistant Professor in Electronics from india. All of your videos are excellent and very informative👌👌👌 Everything is well explained with schematics & design. I really appreciate your hardwork, patience & dedication behind every video ⚡
@greatscottlab2 жыл бұрын
So nice of you. Thanks for the feedback :-)
@elcomesiingwa19135 ай бұрын
That device you call garbage has a voltage doubler circuit of which if connected to your diy high voltage circuit would produce just about the same Arcs
@norlin762 жыл бұрын
I use the ready made modules for making "static grass applicators" (for putting fake grass on things like model train tables, gets the grass particles to stand up)
@chrisakaschulbus49032 жыл бұрын
that's so psecific and niche... but i kinda like it :D but couldn't you use a balloon and rub it against your hair for static pulling action?:D
@norlin762 жыл бұрын
@@chrisakaschulbus4903 maybe, but usually you're applying it to a large area so it nice to just hook ground wire to that area and then shaker the grass all on.
@chrisakaschulbus49032 жыл бұрын
@@norlin76 i wasn't too serious, of course the constant and probably more controllable nature of it seems far better :D
@shiroumxm2052 Жыл бұрын
i wanan try that.. onces you made the static grass aplicator, how many seconds can you actually press the button¿¿
@norlin76 Жыл бұрын
@@shiroumxm2052 I haven't tried holding it down for an extended period, but for the 20-40 seconds or so needed to apply static grass it has no issues.
@unknown-ql1fk2 жыл бұрын
Omg, how dare people have the right to buy a spark generator and have the PERSONAL RESPONSIBILITY to understand what they are buying
@ankursardar470710 ай бұрын
I'm sorry but where are you trying to go with this??
@kayakMike10009 ай бұрын
@@AcademicDisappointment I bout some sharp knives on amazon. I got a little cut, think I can sue?
@sebastiangudino93773 ай бұрын
@@ankursardar4707That the dude is trying his audience of mostly electrical engineering and experienced hobbyist like children's "Be careful, that 7kV arc gets hot and can shock you, you could burn your fingie 🥺"
@PatienceDepleted2 жыл бұрын
I like that he said it will hurt WHEN you touch the high voltage output. There is no "if".
@cezarcatalin14062 жыл бұрын
It’s almost a law of nature that those electrical engineers who didn’t yet experience a taser shock will tase themselves on purpose at least once in their lives.
@MichaelOfRohan2 жыл бұрын
Hey, never, ever complain about being able to source electronics. I dont care what it is or what its for. Your ability to procure electronics without them first being spit shined by uncle sam is a human right.
@diablominero2 жыл бұрын
The high voltage module you say not to buy is similar to one I tried to use to power a TEA laser. I wasn't able to make it work, but that was definitely a science project.
@mynameisZhenyaArt_2 жыл бұрын
Also you can make a Birkeland-Eyde generator for NO2 and nitric acid with the HV generator...
@mistirion49292 жыл бұрын
Bro you've got to be kidding me. I've had this thought of buying one of these for years and one week ago i decided to buy one of them (knowing that they could never reach the specified voltages) Just perfect
@annoloki2 жыл бұрын
Changing from the BJT to MOSFET can be done by removing the diode, as current has to flow back out of the gate to turn it off. I also put a fast diode (eg, a schottky) between the mosfet and the transformer, as the body diode is usually slower. You can also help protect the transistor by making sure the current can come off the secondary coil of the transformer straight away, with use of high voltage diodes/capacitors, rather than making it have to produce a high voltage spike to produce the arc before current can flow. The quicker you get the current off the secondary, the less there is trying to flow back on the primary.
@computermaster360 Жыл бұрын
_"with use of high voltage diodes/capacitors"_ - that would pretty much make it identical to the "garbage device", as can be seen here: watch?v=mTx8pMHo4jI
@Dinco422 Жыл бұрын
I love the fact that you are able to buy these!
@Brownsy672 жыл бұрын
Heck yeah. Your videos were the catalyst for me to start understanding HV and high frequency electricity. Thank you for making this hobby easier to understand, as well as for ideas to use in my projects. Stay safe, and see you in your next video.
@greatscottlab2 жыл бұрын
Great to hear!
@urnoob552811 ай бұрын
seriously of all the youtubers u chose this coward to learn about hv?
@antonycasanova40672 жыл бұрын
Ich liebe alle Videos von GreatScott!, du lernst wirklich viel von ihnen, danke!
@emersonslab16377 ай бұрын
My heart sunk when he said "scary arcs" with tesla coil like the one he made. I made one that makes well over 5 feet arcs of lightning THAT is scary!
@sublimationman2 жыл бұрын
That $10 one in the beginning, I used one to make a rat killing trap. Used a circuit board with a zig zag trace in the bottom of the box with one lead of each side of the high voltage touching, then when the rat steps fully inside hit weight triggered a switch under the circuit board turning on the device and giving the rat a deadly shock through his feet. Worked great until it rained and ruined it.
@ianhosier40423 ай бұрын
I replaced the 100 ohm resistor with 2k2 and also placed a 4700pF capacitor across the primary. Result was nice arcs with a current draw of less than 0.5A at 4v and no more blown or overheated transistors. 100ohms is far too low a value fot base resistor but a nice way to sell lots of those kits! The capacitor limits the peak voltage seen by the transistor and also reduces the drive frequency reducing switching losses and coil impedances.
@BertoldVdb2 жыл бұрын
I used the first module to charge a capacitor for ESD testing. It was overpowered, but the other modules output AC so an extra rectifier would be needed. Output voltage is around 8-10kV.
@ragadoodle2 жыл бұрын
The way you say circuit is probably the best pronounciation of it i have ever heard.
@nathanielluke20842 жыл бұрын
Hi GreatScott! Thank you for this video, i find it very interesting. May i suggest you to use the dark mode theme for your EasyEDA? The sudden brightness change really hurt my eyes when im viewing it in the dark (does this suggest an automatic brightness dimmer like the sound adjuster? JK XD).
@greatscottlab2 жыл бұрын
Didn't know they had a dark theme. I will have a look ;-)
@Zebra_Paw2 жыл бұрын
The automatic volume adjuster is not suitable for people who are using the TV integrated speakers (you would see the volume level changing on the screen) or some device that can’t be switched with a remote control… I think a such thing should be software based, because you first filter the signal, and then add gain depending on how high you want the volume to be.
@scottmorgan53702 жыл бұрын
I'm thinking that the high frequency is the reason for the fins in the secondary coil. Not for heat, but in order to wind the coil in shorter segments. Often a different wire must be used. For instance a 40 AWG/ 170 strand Litz wire might be used in this application.
@ProDigit802 жыл бұрын
Interesting to see that a lower frequency results in a more yellow arc, and melts the output wires.
@STRA1GHTAHEAD2 жыл бұрын
Yellow arc is from trace sodium ions, practically meaning that something is burning.
@vybusnyblogcz2 жыл бұрын
Probably worst kit ever. The fact it died spontaneously, says a lot. If you need HV for anything, save yourself a headache and buy that black module. It pays back in your time quickly.
@cezarcatalin14062 жыл бұрын
You can replace that NPN BJT with an N-Channel SiC power JFET. The positive bias makes it behave like a npn BJT (kinda) and a high negative bias turns it off. There are SiC JFETs with the max DS voltage of several hundred volts or even over 1kv.
@EkholmAndreas2 жыл бұрын
Can you recommend any?
@mike_x489542 жыл бұрын
I got one of those 'high voltage spark generators' from eBay 6 years ago. Used it in a Halloween prop on the wall. Works as needed, I made sure no one touched it.
@excitedbox57052 жыл бұрын
These are not just tasers. They are used for electrical ignition and powder coating sprayers.
@m4jci62 жыл бұрын
I bought a few of these last week and they didn't work out for me so luckily you came to the rescue as always.
@17hmr2432 жыл бұрын
1 its not a taser - stungun. tasers shoot barbs and wire 2 epoxy cost more then these do. 3 sounds better
@peepopalaber2 жыл бұрын
The "DC Boost Step Up Powermodule" is fantastic. It literally IS a pulse generator for tasers.
@christopherleubner663311 ай бұрын
The HV module literally is the one they use in Tazers. It is a inverter that charges a small capacitor that discharges through a sidactor or mosfet to a small hv pulse transfotmer. Used them for laser flash lamp tube ignition.
@Dr.Cosmar2 жыл бұрын
Natural selection needs some way to work. If you die, after ordering this, that's natural selection. I used it, and a resin cast to make a DIY arc lighter lightsaber hilt.
@baruchben-david41962 жыл бұрын
I don't see why the Amazon product is such a bad thing. Yes, you *could* use it as a taser, I suppose, but you can misuse almost anything. You can break a glass jar and use a sharp piece as a knife. You could even hit someone with a chair. This doesn't mean a chair should come with a license. I've actually played around with one of these Amazon devices. It does produce a nice, fat spark, and it's true that if I were to connect with it, I would be very unhappy about it. I'd be unhappy were I to connect with the power coming from my wall sockets, too.
@tronixfix2 жыл бұрын
I used to make tasers from them with a single 18650 and small micro usb charging board. And yes… they hurt like crap, had to once use it in an emergency.
@m_a_s60692 жыл бұрын
Scott, I think you are overlooking some legitimate reasons for having a HV transformer like the one at the start of your video. Personally, I use these and similar ones for igniting gas and atomized oil sprays in various furnaces and heaters.
@foureyedchick2 жыл бұрын
The purple tubing with the orange tips reminds me of the tubing used by machinists to pump water or coolant to CNN machines and lathes.
@danielmendes56822 жыл бұрын
i was googling about those HV generators yesterday and then you posted a video :D
@knowurself49992 жыл бұрын
*Word of Caution* a similar type o circuit, self build transformer and a diy zvs, while testing on my pinky finger did some huge damage to some extent i could not feel my pinky finger for 3 months and only fully recovered after 6 months, take my advice don't try to be a test subject yourself you can make mistakes Like on high output side, never touch 1 wire in one and other wire in other hand as high voltage can pass through your heart, always keep one hand behind your back
@john-fc6pb2 жыл бұрын
Using rechargeable arc lighter more than 4 years. It's awesome!
@ooohgooo8 ай бұрын
As somone who did post-doctoral research in pain and currently doing electric brain stimulation devices (much lower voltages and frequencies))), I find the fact that you don't feel anything at 250 kHz (it's higher than any action potential and anything above ~5 kHz should be filtered by RC of the skin anyway) very thought-provoking... If there was a way to tune that frequency to find the exact frequency threshold (and maybe find a threshold at which you feel touch, but not pain) and compare it against the membrane models of the different sensory fibers (e.g. using Neuron or Sim4Life) - this could result in a good Nature paper. However, even as is - this finding (if not previously published) is worthy of scientific interest! Well done! :)
@Teth476 ай бұрын
I'd wager it's more a matter of skin effect than anything biochemical. The current just isn't reaching the nerves, so they have nothing to report until the heat permeates the outer skin layers.
@EgonSorensen2 жыл бұрын
10:32 - Enjoyed the video, not enjoying when things burn and go defective. At least the ones from amazon doesn't have this 'issue'. Running such small transformers with a ZVS circuit is just begging for the windings to burn and getting destroyed. It switches huge currents. Take a look at the bottom next to the green wire - enamel wires are hanging out, so no more sparks from this one. Perhaps a video on how to wind your own high-power transformer?
@STRA1GHTAHEAD2 жыл бұрын
Yeah, I was like, GreatScott is usually super neat, and with this he's approached destruction videos. Nobody is safe from that, apparently.
@stromundspiele6702 жыл бұрын
5:46 I think you are wrong, 1. in my experience one coil is backwards in your drawing, didn`t start to oscillating that way, the vcc should be oposied of each other . 2. it works a bit different. the current starts to flow over the base -> the collector current is rising -> the transformer rise the base voltage -> the base current is rising until the coil is saturated and the base current starts to sink -> the collector current is sinking -> it induces a negative voltage in the base coil. this starts a chain reaction until no current is flowing and it starts all over again. please excuse my miserable english
@Broken_Yugo2 жыл бұрын
Correct, it's a "blocking oscillator", primary and feedback need to be antiphase. This is why phase dots on schematics are important.
@Joseph-zt5uv2 жыл бұрын
Great Scott!! It's been ages since I saw a notification for your video. Glad to finally see new videos.
@Pelican_t Жыл бұрын
You can make bigger arcs by hooking up a 12V relay circuit to 2 transformers. I usually reverse feed a step down transformer because that's what I have on hand and then step up that stepped up voltage with a step up transformer and then the arc is able to melt metal. All powered by a 12V battery.
@sleepwalkerbg12 жыл бұрын
Heyyy, Great Scott, great job, again! About so called ZVS driver (sometimes called Mazilli driver) , that ZVS means Zero Voltage Switching , and is a technique that can be applied on almost all SMPS topologies. Often this Mazilli circuit is called ZVS FLYBACK that is wrong. Real name is resonant push pull ZVS converter. ZVS is technique used for so called "soft" switching , exactly in time where voltage (ZVS) or current (ZCS) across the switching element is zero, thus reducing switching losses. And first circuit with BJT is so called "blocking oscillator" and is used in old type fluorescent lamps converter/ballasts which were battery operated. And YES it can be done with MOSFET but you need PNP gate discharge speed up circuit and current ramp control. It's a little bit tricky but it can be done ;) Thank you for your detailed approach and great videos.
@Chuckiele2 жыл бұрын
They usually call them zvs flyback driver because they are commonly used to drive flyback transformers but yeah, its pretty misleading.
@fallingwater2 жыл бұрын
This video has sold me on the cheap one that makes the larger spark. Stay away from the thing when it's working and you'll be fine. Regulations, bah - it's Germany, if your regulatory bodies could regulate the grass in your fields they would, doesn't mean you have to care.
@mfx12 жыл бұрын
I use the first type for specific high voltage ignition systems that need to be high energy and battery powered rather than mains which many systems are, so they do have their uses.
@MrFish19682 жыл бұрын
I love your writing and little diagrams, so neat.
@MikaelIsaksson2 жыл бұрын
I am exploring various ways to make the best fly-zapper (specifically houseflies) since we live out on the country and every time the sun shines, a lot of houseflies appears. I have noticed some things about the flies. They like to land on white surfaces. They like moisture. They like heat. They navigate somewhat with UV, and is drawn to it somewhat, but not as much as heat+moisture+white. I want to make it such that I use a light-bulb socket in the ceiling. So, my constraints are, not too heavy circuits, so no fat mains transformer here, would have to be some ugly and dangerous Cap hack from mains (230 v). It would have to involve a light-bulb and a white surface, it preferably would involve a small jar of warm water to get that moisture, if it doesn't make it too heavy. I am leaning towards a plastic white PVC pipe with a light-bulb at the bottom, a grid a bit out around the pipe (vertical pins), and some way of maybe having a small glass jar of water below it... something like that. So it is interesting that I'm starting to see a lot of videos like these in my feed :).
@anuardau32569 ай бұрын
Simply take the square root of the ratio of primary to secondary inductances and this will give you the turns ratio. N = SQRT (Lp / Ls) = Np/Ns. Cheers….
@gymbro8982 жыл бұрын
you are always right, i am big fan of great Scott
@greatscottlab2 жыл бұрын
Thanks :-)
@memejeff2 жыл бұрын
Amazing video! I bought some of those tazer modules a while ago. I found that they can cut a very tiny hole right through paper so I want to use one for a cnc paper cutter
@im1random2632 жыл бұрын
Have you also tried if they can cut a tiny hole right through a finger if you accidentally touch it
@memejeff2 жыл бұрын
@@im1random263 nope, I have messed with high voltage since I was 6 and only got shocked once then. I am careful
@Reaper0352 жыл бұрын
These modules also can put tiny holes into glass. Wouldn't recommend tho.. (Tested with an dead light bulb.)
@memejeff2 жыл бұрын
@@Reaper035 oh my, That sounds dope. Quite intruiging how powerful they are.
@ash07872 жыл бұрын
yeah or in my case it can burn a microscopic hole through an olive or other fruit and creates a smell
@MrVeryCranky2 жыл бұрын
The latter unit with the flyback type transformer can be significantly improved by coating the windings with multiple layers of super glue, allowing each coat to dry before applying the next. This significantly reduces the likelyhood of arcing between windings.
@jacobwcrosby2 жыл бұрын
I use these as igniters. Potato guns and grills mostly...
@francescotrevisan445310 ай бұрын
I think that I will continue with the "dangerous" and "illegal" high voltage generator😂. Just to put some spark, fun and danger in my life😂. I enjoyed the video.
@stevetobias48902 жыл бұрын
Just started watching, I purchased that big round black one on eBay and yeah it's scary. I then purchased a few of the second ones you showed. Have not yet started experimenting with them however. Love your videos, your a star when it comes to explaining stuff, thank you.
@AWildNoodle2 жыл бұрын
dont know why exactly but the thumbnail reminded me of a EDM machine, would be an interesting experiment although spark generators for EDMS are pretty specialized
@Geniusinventor2 жыл бұрын
Can you open the high voltage generator . To see how it made or working please;)
@Chuckiele2 жыл бұрын
Sadly they are potted in resin.
@aathish042 жыл бұрын
Could you also talk about how the circuit inside the taser module (which you asked us not to buy) works?
@greatscottlab2 жыл бұрын
Maybe next time ;-)
@aathish042 жыл бұрын
@@greatscottlab Looking forward to it!
@ipissed2 жыл бұрын
It's the same, 2 windings encased in epoxy resin just like he described. I just buy them for $3, it's not worth building them. Or just buy a taser for $7 if you want a taser.
@ash07872 жыл бұрын
i've seen schematics, I think its a royer oscillator connected to a small voltage multiplier, some people talked about it on the BigClive video.
@alouisschafer72122 жыл бұрын
These HV generator modules are really strong. Feed them the max rated voltage and they will produce arcs an inch long. But they burn out quickly! So keep to to a few seconds at a time.
@rubenproost25522 жыл бұрын
One generally keeps the smoke in with a heat sink.
@gusstavv2 жыл бұрын
Soooo... at the end, which circuit works best as a "having fun with no deadly and painful HV, while not changing the transistor every few minutes"?
@bastighg15595 күн бұрын
Fun fact: if you take apart the "garbage device" you will find the same mini transformer connected to a voltage multiplier
@yousefkhalil47652 жыл бұрын
If you connect one end of the cheap HV generators to a resistor of 10k-100k ohms and isolate it with heat shrink, the arcs end up being of lower current and higher frequency, essentially being like the diy generator.
@gabrielhacecosas2 жыл бұрын
Actually I think that these generators are used for the starting spark of burners and water heaters. That's why they are so cheap, because so many of them are manufactured.
@omsingharjit2 жыл бұрын
9:42 for beginners ... it's kind of okey to touch purplish Blue spark but don't try to touch the wire which produce yellow white spark it can kill you otherwise burn you due to skin effect .
@patracy2 жыл бұрын
Got 45 seconds in before I left this video.
@DoctorX172 жыл бұрын
I would 100% prefer pain from burning over pain from shocking
@Zebra_Paw2 жыл бұрын
A mosfet would have been fine with a pulldown resistor I think (or maybe a little bit more circuitry)…
@peterbonucci96612 жыл бұрын
That transformer circuit was used in ozone generators at one time. It is *very* sensitive to the choice of BJT. Even if you get the correct transistor, only the low gain ones work. Since Fairchild quit making the low gain ones almost 10 years ago, they are probably very hard to get. The small arc you got in the beginning is what they're designed for.
@shourovpal21682 жыл бұрын
Ever watched the game of Cricket?I always wonder how the digital cricket stump works!please make a DIY version of that stump!
@Ma_X642 жыл бұрын
Try to design a adjustable HV source. Like a laboratory thing. As you know, laser printers uses several such sources to operate with a toner. Do precise source can help with doing prescise things. Note that your device gives you an high frequency AC voltage but a factory one makes DC. Not every application can consume AC and so for printers. You can't attract something with AC and it quite hard to insulate it because it causes heating of most insulators.
@electroinduction15122 жыл бұрын
Great video as always,i have couple of those transformer and a month ago i tried rewinding them and used a half bridge driver to drive it,it produced very long arcs close to 3 to 4 cm but not for long😅 the insulation failed and arcs started flying out of the coils.
@kevinslattery57482 жыл бұрын
Which xfmer? The one with the separation disk's or the kit supplied one? What voltage and frequency? Did you use alternating voltage or chopped DC? I guess if you used a full bridge then it was alternating? Edit re-read your post: half bridge so chopped DC?
@chrisakaschulbus49032 жыл бұрын
got one of those cheap ones too... i love the fact that you can buy stuff like that for so cheap ^^
@TheTomCruiseLover Жыл бұрын
If only the Titanic had this circuit for it's Arc spark gap Marconi radio transmitter they could've increased their emergency SOS broadcast range to 2,000 Miles !!
@VictorC1732 жыл бұрын
Some ferrite cores I use with the zvs circuit get hot, and it's not loss in the wires, maybe the core goes into saturation or something, but I thought all the energy was stored in the capacitor and inductor ... I always need a minimal air gap for best efficiency.
@Reaper0352 жыл бұрын
Well, I don't get the correct word right now but it's basically an induction heater. Usually (larger) transformers use laminated sheets of metal instead one piece of material to avoid/reduce this problem. Your air gap does the same.
@VictorC1732 жыл бұрын
@@Reaper035 I just wanted to have a toroidal ferrite transformer with the zvs circuit, but it's an impossible combination...
@Reaper0352 жыл бұрын
@@VictorC173 It would be possible, but you would also have to lower the frequency low enough for it to be usable and not end up as induction heater. Or maybe there exists laminated toroids but idk, I'm no expert. (I think angular laminated toroids exist.)
@VictorC1732 жыл бұрын
@@Reaper035 ah, it's not iron cores, I mean ferrite toroids not working with my ZVS circuit, the core heat up fast with only drawing 6w of power in idle, while a ferrite transformer with a minimal air gap consumes less than a watt...
@Reaper0352 жыл бұрын
@@VictorC173 I'm not sure but I assume that ferrite cores are electrically conductive as well as iron cores are. And the changing magnetic field of any transformer causes Eddy currents to form inside the iron or ferrite core. And these currents are what causes the heating. When you "slice" the iron or ferrite core in smaller, insulated pieces this mechanism decreases. That's why laminated iron cores are usually used instead of one giant slam of material. (Btw: ferrite is iron-based, afaik. And basically iron particles backed together in whatever form you need. I think they are just cheaper.) Take a look at Eddy current videos, Scott also has at least one of them explaining it. Also ElectroBoom has one with an good explanation. However: that drop of idle power draw is quite significant from just one (or two) air gaps!
@TheFreak111 Жыл бұрын
Mr Scott, this video was exactly, and I mean exactly, what I was looking for. Needed a small cheap high voltage driver with tunable power and frequency, and thanks to your video I think I can make one.
@cosmicyoke10 ай бұрын
@4:20 maybe the transistor also failed because you used an input of 4 volts x 2.8 amps, normally the recommended voltage yes is around 3.6-4 volts, but usually from a battery, which not only has internal resistance, but taking into account the resistance of the primary and feedback windings, will probably draw far less current than what you were supplying with your power source- basically have to match the impedance.