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- čas přidán 31. 08. 2018
- I should have been warned: Some viewers on our summer project were against a gun on the tank. But I did not listen. This video shows what happened and how I was punished.
In Switzerland, every adult man is in the army and has his weapon at home. Maybe this is the physiological reason for my choice. I am no psychologist; I am an engineer. So let's start with the story about How-to build a rail gun or a coil gun. Or how to not do it...
Links:
DC-DC converter: s.click.aliexpress.com/e/cOSWd3Hq
Capacitor: s.click.aliexpress.com/e/nM1zYpE
Thyristor: s.click.aliexpress.com/e/XhOzEO8
Copper Wire: s.click.aliexpress.com/e/bfM2xSmy
USB Isolator: s.click.aliexpress.com/e/H1LnZPi
Batteries from Hobbyking
Instructable where I found the diagram: www.instructables.com/id/Maki...
GreatScott's video: • Make your own Coilgun
Supporting Material and Blog Page: www.sensorsiot.org
Github: www.github.com/sensorsiot
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Equipment in my lab: www.sensorsiot.org/my-lab/ - Věda a technologie
Controversy aside, this video is a superb lessons learned. It ensures the following;
1) Never allow people to say no, it only encourages opposite. Just like when we were kids.
2) A scientist always learns by doing, not just theorizing.
3) There are always risks. RIP your power supply.
4) Transparency is critical to ensure progress is made.
Congratulations on a very SUCCESSFUL series of failures and corrections.
It's why this channel will continue to flourish.
And I still hope I can repair the power supply. Not easy for me...
@@AndreasSpiess A tragic digital outcome that may wind up being very costly. I wonder, would if an in-line fusible set of test leads prevented the damage.
just make a gun that shoots capacitors! You've already figured out the hard part!
You are right. But it would not be "green" ;-)
I love this suggestion! 😄
😂🤣😂🤣
No no no, there is a point.
I'm pro-coilgun.
Don't shy away from high voltage. I've done a lot of projects with it, (been a while since I've put a video online though) Do some more work on the coilgun, please! :)
As other's have said, free-wheeling diode, better DC-DC converter protection, and discharge resistor on electronics. It can help to have a neater setup too. High voltage electronics is the most fun! Half of that is blowing up components! Best thing is... you know when something isn't working, and it alerts you to the fault instantly, no slow painful debugging!
I'd be more afraid of a metal projectile hitting me at high speed (after all, normal guns are deadly because they throw a metal projectile at a high speed) than of high voltage.
Pretty easy not getting shot. Just don't stand infront of the barrel (or behind it if you haven't established the coilgun's polarity) As easy as not getting hit by a train. Don't stand on the tracks. Sure, some people get hit, but the world is probibly in safer hands without them.
GRBtutorials: Only if they hit you ;-) In Africa they shot at me with a machine gun, fortunately they did not hit. But it was a lasting experience.
As I said, I would probably not give it to everyone. But it is the same with knives or cars. They are potential killers.
And what if you accidentally press the trigger? Or move the robot meanwhile pressing the trigger? And let's not forget that you could accidentally hit someone (or something) other than you.
LMAO @ the 'Chinese 400V'... Unfortunately, it's dangerously accurate too!
This device was one of few which actually exceeded its specs. But in the end, did not survive. Many parts do not get up to the specified voltages or currents
Better check your TV, computer and anything that has a switching PSU. Most will have these "Chinese 400V" capacitors in them. And they are not a problem - unless you exceed the ratings, which is what happened in the video. The cap didn't blow because it was poor quality but because its voltage rating was exceeded (the power supply produced more than 400V).
You are right. But usually things have a rating and a max rating which is not the same. And the typical rating is printed on the parts. In this case, the typical and the max was pretty close. And the producer of the converter should have known that his device easily gets over this limit. But I do not blame anybody for a 5$ device!
There are two problems that caused the capacitor to explode.
1. In order to produce 400V from a switching converter, you need spikes of greater than 400V which are smoothed out, capacitor should have been 450V.
2. No load on the negative 400V rail, so it will continue to soar past 400V as long as there is a load on the positive 400V rail. Ohms law will give a suitable resistor value.
Both are noob mistakes from people who do not understand practical SMPS design, only one mistake is yours. Multi rail SMPS designs often only have one rail monitored by the feedback circuit, the other rails are a case of "hope for the best", PC ATX supplies monitor more than one rail.
In hindsight would have been better to ask the electronics community for advice, rather than throwing money at the problem. A quick post on eevblog forum may slow down the video making process, but others would see the flaws in your design before you build it.
@@AndreasSpiess please contact with me. shohag5050@gmail.com
I think there is a difference between rail gun and coil gun!
You might be right. I did not research. I just found these two names for similar devices
Coil guns uses coils and railgms uses rails(captain obvious). That is the difference... But they also depend on different physical laws and the railgun is much more difficult to get working...
I changed the title to be correct.Thanks!
Look at all that you learned. Maybe you should title this video, Diary of a wimpy engineer. You surely can fix the power supply. So you and your viewers learned so much respect for high voltages and high energy and doing more thorough researxh. Good for you. Now it is time to get started on the RAIL GUN!
One blows your power rails, the other doesn't :)
Buy a hundred optocouplers on alie and some flyback diodes. With battery powered HV it's optional, but ideally I'd try to split the ground between HV and Vdd. The other way is to carefully put diodes for flyback and voltage clamping. More resistive paths between the MCU and HV is also a good idea.
Despite the failures in this video it's been one of my favourites. Great determination to get it done and fix the design. Brilliant.
Thank you. I thought it is worthwhile to tell the story. I also had a lot of fun when it finally worked.
do an episode on repairing the lab power supply!
We will see if it is worth while...
@@AndreasSpiess well given that education and experience are the most valuable things you can have... I think it is!
Andreas Spiess i suspect its a reverse polarity fast switching diode across its output capacitors. the diode probably failed in a short circuit mode if that is the case. sometimes there is mutable side by side to improve their current handling abilities. atleast that was the case when i did something similar to one of mine.
i "repaired" a lab bench psu similar to that one, it had some isues with diodes, relays , voltage regulatos and some op amps, and i say "repaired"cause i can't use the psu on the parallel mode, so i can only reach 30v dc instead of the 60v
@@AndreasSpiess GreatScott repaired his, and it only had a burnt diode.
Interesting experiment. Learning about high voltages and the related safety precautions for self and your equipment is always a very useful lesson
You are so right!
GreatScott: builds a coil gun
also
GreatScott: _Why am I hearing boss music ?_
Ouch, you must not switch the thyristor/SCR gate directly from anything that cannot handle the high voltage! Once the device conducts, the high voltage will be present on the gate as well - and successfully blow up anything that is connected to it unless it is rated to handle it. Just look at how a thyristor is constructed and it will be obvious what has happened.
There are optotriacs/optothyristors available which have the gate galvanically isolated (basically have a built-in optocoupler). Alternatively, you can use an IGBT or a MOSFET, in either case the gate is insulated and you won't have this problem unless the device fails.
Always count on the device failing! 😎
If you do, it won't.
Well, yes, but if the optocoupler (whether standalone or one in the optothyristor/triac) blows, there isn't much you can do. MOSFET/IGBT is a bit more risky, there I would probably add the optocoupler as an "insurance" even if it strictly isn't required because when these devices fail, they like to fail short, with all pins shorted together. The resulting BANG will likely take out everything nearby.
Jan, can you recommend one? My optotriacs (MOC3063) have a zero crossing detector, which in this case, is probably not a good thing.
If I remember correctly, MOC3011 lacks the Zero crossing Detector.
Murphy's first law: if something can go wrong: it will do it!
I mostly like the fact that you showed the fails and casualties. The trip to success is better than the outcome sometimes. So much learned. Thank you.
You are welcome!
Thank You for making so many newcomers aware of the harm that mistakes can make. I find the electrical and electronic fields fascinating. Keep up the good work.
Of course. It's really cool . Maybe , maybe . Look here:
! New: Apocalypse Coilgun, Fallout Coilgun
czcams.com/video/G9-jKWPyMFo/video.html
See also: Portable Super Coilgun:
czcams.com/video/rclLsQ9nyeg/video.html&feature=youtu.be
czcams.com/video/-mjDqp_oWZk/video.html
czcams.com/video/YLOYxsqvjw0/video.html
czcams.com/video/vErqh0DO_S0/video.html
czcams.com/video/OFIQ3pcFZpU/video.html
On the other hand I also learned a lot ;-)
he should've mentioned ElectroBOOM too :P :P
I did not know that he built such a device.
Andreas Spiess I think he made a rail gun🤔🤔 and he blew up components too 😁😁... love your videos though learned a lot...😊
Vaibhav Hayaran he built a coil- and a railgun
@@vaibhavhayaran Electroboom blows up components when just blinking an LED.
Just liked the video due to the line "This is what electric dreams are made of"
:-)
I love your projects. It gives me the results I'm looking for without messing my parts 😋
Thank you!
You are welcome!
Great video Andreas! Second video about failures I've seen this weekend. (Maker's Muse) Its wonderful to hear that we all go through the same albeit trying process.
Thank you! For me, one video was enough ;-)
did you shield the esp from the emp created by the coil?
I also wouldnt connect anything like a lowvoltage microcontroller to a highvoltage system. you could have used a optoisolator or a relay. the resistance on your wiring in the thyristor,cap,coil circuit could have created such a high voltage drop that exceeded esp's limit.
In the end, I learned that ;-) Took a while, Though.
good point, you re for sure right with the EMP, it could have inducted through the WLAN anenna, I/O pins or even through the power line. However the ESP as such is EMP potected by it's metall cover, maily to shield the environment from the ESPs noise - unfortunately it's having some "antennas" ouside that catch up environmental stuff and feed it to the ESP ...
Well, in this video Andreas does talk about using the opto-isolator and the reason why he didn't use it. It wasn't fast/powerful enough for the 10ms pulse. I agree with a previous comment about using the isolating transformer. Since it just needs to trigger, rapid energizing/de-energizing is enough to cause the magnetic field to charge the other coil and trigger the thyristor on the other side.
Also, a blocking diode for the coil to keep it from back feeding into the thyristor
A rail gun is different, it conducts the current through the projectile using rails rather than in a coil around it.
Other viewers also pointed me to the difference. I changed the title.
Andreas, this is by far the best video you made. My condolences for your equipment. Let me know how i can buy you a beer. You're the best!
Thank you. There is still hope I can repair the power supply.
This was fun to watch although I feel the pain of the failure as I have experienced the same myself with several failed projects.
Humor sometimes is a form to relieve tension ;-) With the help of some viewers, I am confident that I can repair the Power Supply with a new Opamp. There is hope...
V=R/I ?? Has Ohm's law been repealed? Is this an alternate universe?
Yes!
Asking to myself the same question
I love your Electroboom moments 😁
:-)) Fortunately, I was not hit myself as he (seems) to be quite often.
A trivial number of destroyed components when compared to the damage done in a typical Electroboom project.
Kudos for admitting to your fails and documenting them just the same way you do with your many successes!
In the end it worked at least ;-) So it was ok for me.
I knew this was going to be good. Actually it was fantastic! I love the warts and all videos (probably because I often make mistakes) To see Andreas have the same issues did make me feel like it’s not just me😬
I have to say, one of my most favourite videos to date. I love being a Patreon and the community that Andreas has created.
No doubt I will be watching this many times as there as so many lessons to learn.
I must admit I was gutted by the power supply failure, I know how fond you are of that power supply. Can you fix it and show us how in another video?
A very happy Sunday morning, thank you Andreas 👍🏴
Errors are the fuel for learning. If you do not make a mistake it is quite clear you did not learn because you (obviously) already were able to do it before you started. And thank you for your Pateron support!
A very useful little part you can use for galvanic isolation is the 'B0505' dc-dc converters and similar. You put in 5v and get 5v out but isolated. It's enough current to drive even some relays. All for a couple of dollars. You can find them and similar parts on AliExpress searching 'isolated dc dc converter'.
As a side idea, why not make a gun that shoots capacitors by blowing them up, you already had a working prototype at one point.
Sorry to hear about the power supply, maybe an opportunity for a repair video?
1. Just ordered a few of these B0505. Look like a good idea also for other applications. I am not sure how fast they would be. But I can try when they arrive.
2. Some other viewers also experimented with caps. It seems to be an explosive device if used the "right way"
3. I hope I can repair it. And I will show it if interesting.
Wonderfull !! Too bad of you power supply. High voltages... been there, done that. I did experiments with car coils (Auto Zündspule), not the regular ones, but a lab version of around 40cm's long and 20cm's in diameter.... also known as Ruhmkorff zündspule. Awesome... and also a little dangerous. The explosion of capacitors... tell me about it ;)
My voltages, fortunately, were much smaller than the one produced by these ignition coils. And I hope, I can repair the power supply. It is an old one and maybe not so complicated.
Hi Andreas! Vor isolation you may want to use something like a VOM1271. A Optocoupler that generates a voltage at the output. I use it all the time, they are so useful!
Yes this is the modern way to go.
Unfortunately, the Thyristor needs quite some current. But I ordered a few VOM1271. Thank you for your tip!
excellent video. Thank you for sacrifice of all the parts.
This was not the plan ;-) Fortunately, I was able to repair the power supply in a later video.
I was with my headphone, I shit on myself with the shot sound
Never watch my videos with headphones. Too dangerous ;-)
Just make a gun that runs on the explosion of Chinese capacitors instead of gunpowder.
Right!
I have the same 400v converter for a geiger counter project. Thanks for the heads up on the exploding caps!
Hopefully, it will work. I did a project with a commercially available Geiger counter.
Thank you, just found you & subscribed. Helped me to learn a few things especially on what not to try, sometimes that's more important to help train someone. Also are you going to make a repair video on your power supply?? Would like to see what all went wrong with it, instead of just me guessing at it. Thanks again, Tom.
Welcome aboard the channel. Maybe I will make such a video...
Thank you, will be waiting to see just what is next. Have a great day.
"Chinese 400V" ! I laugh at it so much, because is soooo true :-D
Ohm's law has changed since the last time I used it.
I loved the video. So very, very well done. Thank you, Andreas... :)
Thanks so much for this video! It actually gave me some more ideas for safety considerations and saved me an exploded cap in the switching converter (I have the same model!). I'm using a 2200uF capacitor 400V and 30uH coil made of 12AWG wire. I optimized the coil design with COMSOL to ensure that by the time the bullet reaches the end of the coil, the magnetic field is already collapsed. The current peak will be almost 2kA inducing a 0.5T magnetic field for 0.5ms and 4ms until full discharge of the coil. One thing I am very afraid of is if the thyristor gets damaged and becomes shorted - in that case nothing restricts the backlash from the coil and the capacitor will get "recharged" with nearly all its energy almost instantly which would at worst result in a huge explosion. In order to prevent it, there's a diode in parallel to the coil which should offer additional level of protection. Regarding optoinsulation - it is another must! I am using an optotransistor for triggering the thyristor.
Good luck with your project! I am sure it will work with all the considerations you do.
@@AndreasSpiess thank you! After some more simulations i decided to use a 5 stage design with 470uF 400V capacitors. I also learned that encasing the coils inside steel pipe plugged with steel caps on both sides can increase the magnetic field 4 times! I can't wait to see if all the math will pay off once i build it!
Just one more question - I got a bit confused with the schematic. Is the thyristor placement correct or is it the wrong one? The way I understand it is that at 8:00, the coil will immediately conduct. Shouldn't the thyristor be placed before the coil (looking from left to right)? You said it was incorrect but I didn't get whether it's incorrect in the schematics you show or are the schematics already fixed.
You need a free running diode! Inductive load!
And a few other small items ;-) Thank you!
@@AndreasSpiess Or one big hammer :-)
The coil is an inductor, when the current is interrupted, a high voltage pulse of opposite polarity is generated. Destructive pulse ;-)
And just to be safe, add a TVS diode to the ESP8266 pins connected to the coilgun.
Hallo Andreas, das mit dem Netzteil tut mir Leid. Ich glaube, es ist nicht schlimm kaputt. In meinem vorherigen Job habe ich das selbe Netzteil gehabt. Ich hatte es einem Kollegen gegeben und der hat genau den selben Fehler erzeugt (ca, 60V Ausgangsspannung). Er hat es aber auch wieder repariert. Es war irgend etwas einfaches. Ich kann mich aber leider nicht mehr an die Details erinnern. Bevor du es wegschmeißt, schau es Dir einfach einmal an.
Vielen Dank für die Info. Ich habe mir gedacht, dass ich zuerst reinschaue und hoffte, dass ich es reparieren kann. Diese alten Dinger sollten ja nicht so kompliziert sein... Werde ich gleich heute in Angriff nehmen.
@@AndreasSpiess Das könnte auf jeden Fall ein nettes Video werden!
Ich habe dem Kollegen auch e-mail geschrieben. Vielleicht kann er sich ja noch erinnern.
+svenpetersen1965: Super. Danke!
Hier ist der Schaltplan des Netzteils:
www.produktinfo.conrad.com/datenblaetter/500000-524999/510075-sp-01-en-Power_Supply_PS_2403_Pro.pdf
Ich habe das gleiche Netzteil und habe es mit Hilfe dieses Schaltplans auch schon einmal repariert. Hoffentlich kannst du es auch reparieren!
Hi Andreas,
I would like to thank you for the interessting video and also for the laugh, especially that caused by 11:15 .
You are welcome!
Cool Video!
I want to build a Very small one (with less then 0.5J ) for a "Show and Explain" Device. This Video is the right "Hint" to start!
The Joules in are not the joules out, because the efficiency seems to be quite small, at least in my case. So you might need something "bigger" than you think ;-)
@@AndreasSpiess ;-) no problem.
I Only want to use a lower voltage but Two Caps with 15000uF. (Enough, i think) I need to build my coil this weekend.
Man I thaught electoboom was most destructive
Maybe, maybe ... Oh yes of course ... See also: Portable Super Coilgun:
czcams.com/video/rclLsQ9nyeg/video.html&feature=youtu.be
czcams.com/video/-mjDqp_oWZk/video.html
ok, so the next Episode is a repair story of a discontinued Conrad Voltcraft power supply. I assume that your DMM confirms the built in meter's reading. The repair shoud not be a big deal, Standard componente as 2N3773 and opamps as 1458. You can replace the 2N3773 by a fixed resistor and change the load to measure if the opamps are still working (probably not). Or you first can replace the suspected 1458 and but this could lead to a short Video.
Be happy that your gun did just kill a few semconductors instead some eyes or something like that. Try a water gun. It is also fun but not so dangerous.
klassich D wise words, thank you for the information and taking the time to explain, as I too was having the very same thoughts. Andreas, pls show us the repair of the power supply.
klassisch D: Thank you for your information. I also hoped I will be able to repair the thing. With your info, it will even be easier.
Dean: Maybe I will do a short video about it if it is worthwhile.
Andreas Spiess Record your repair as people like me would love to see your approach. And how you repair it.
grate project keep it up come back with more
Thank you!
Loving the combination of dry humor and high voltage.
Sometimes necessary (if you have some collateral damage) ;-)
Guns are fine. Ideology is the danger.
Glad your didn't get hurt! Hope your ears didn't start to bleed from the capacitor explosion. This gun is a real killing machine, you should consider something less lethal.
As mentioned, this was it probably for some time. But I wanted to try it out since quite some time.
You can always switch out to ball bearings inserted inside of plastic/rubber/foam bb's.
@@AndreasSpiess don't listen to the nay-sayers. Take appropriate safety precautions and continue on. If nothing else, these experiments are good learning experiences. I'm sure by now you know a lot more about this subject that you did a month ago. I find this sort of work fascinating.
that cap only stores about 80 joules of energy, a .22 cal bulley has about 120 joules. a tiny fraction of that 80 joules actually gets transferred to kinetic energy, the 400v on the cap is more dangerous than the "bullet"
I like the way you make the naration. It has triggered some smile.
Thank you!
Thank you for the very funny and entertaining video and I learned something on the way.
You are welcome!
400 Chinese volt = 4000 German volt from WV = 200 real volt
This channel has definitely taken a turn towards the dark side.
Do you see a trend or just an outlier?
Hehe honestly... this video was entertaining for me mainly because he included the fails on the way to the end result.
Dark side is always the best side.
Come to the dark side, we have candy!
on my way .......
Making lemonade from lemons! Nice job of explaining technical issues from an initial failure. We all learn from failures - that magic smoke!
You are right. If we make no mistakes, we cannot learn, because we already know it...
Hello Andreas,
as usual quite interesting what you did build and thanks for sharing mishaps as well, even it is disappointing it is always a learning for everyone else as well. Having great respect for you work I anyway would like to mention that I think there were several things causing the death of parts :
1. Underestimating free running voltage of the buck converter combined with "cheap" (aka not existing) regulation circuits build in that thing
2. Using a triac/thyristor instead of a transistor because we talk about DC voltage a devcie needing a negative voltage to clear it's on state might be not the best choice
3. Missing to suppress back voltage of the inductor (coil ) which will have quite "some" voltage
In my previous job I worked a lot with switching power supplys and high voltages. Most common thing was always to have a solid TRANSISTOR and a free running diode in parallel ( usually integrated into the transistor case ), most times BU508A later S2000 models. However these are transistors and unfortunately quite worse if it comes to amplification they have very low amplifiction but excellent rubustness. So what I would suggest to mitigate at least some of the risks :
- Get rid of the relais, at least the "small" ones I saw in your video. Given the voltage and amperage you mentioned the contacts will just burn or even worse melt together giving unpredictable results after a short while.
- Use high voltage switching transistors ( low side switching - N channel MOSFET are more common and usually can withstand way higher amperage ), there are several around especially designed for switching mode that do include a parallel diode. It's important to have a valid resistor between gate and drain to change to "off" state in a very short time to avoid burning energy and heating up the device. Maybe Vishay's SIHG73N60E might be worth a look - 70A@600V should be sufficient :D The beauty of MOSFET is for sure the nearly "no energy" needed for driving them but this is as well the pain in circuit design. High side switching for high power applications is not really common and therefore suitable parts for your application might be hard to get.
- Use an isolating device to drive the "switches", most likely an opto coupler but a special impuls transformer would work as well but rises again the issue with back voltage spikes because of it's inductance and will bring some delay into the equation
EDIT: Surprisingly the pictures on the Aliexpress packe do not have the exploded capacitor ... :D What should I now think ?
If the back voltage on the coil will be dropped by a diode I don't know how this could effect the launch speed of the projectile, it will for sure cause some losses in "gun efficiency".
That way the driving circuit should be safe, at least as long as you have only the ground plane as a common level (the buck converter should isolate anyway). If you want to measure the output voltage of the buck converter I suggest again an opto coupler, that's basically the same any switching power supply does, it's having a analog feedback loop through an opto coupler.
This part I'm writing in german (kind of at least :D) : Ich ha no ä paar S2000 un BU508 ummeliege, wenn Du's mit dene probiere wotsch ka ich die au ä mol vorbei bringe - wär schneller als mit de Poschd vu Dütschland ind Schwiz für die knapp 40km ... :)
BTW: If I'm not mistaken a usual coil/rail gun consists of several acceleration stages, similar to the BlueFire roller coasters (EuropaPark) linear acceleration motor. But it would need quite intense tuning for timing to switch them on at the exact right moment, I guess it would anyway be possible with ESPs ...
BTW2 : In my previous job my boss once told me to unplug one thing as the cables where a bit hindering me measuring things properly on the PCB - well ... Any manufacturer did it that way but not Sony, they did build a ground plane from that ... so some capacitors lifting "the hat", some transistors being even more happy to die ... I was overwhelmed buy the kindness of my boss helping me to find the real error and to destroy the already broken thing even more ... That's life ... :) Magic smoke on capacitors is some times a nice mixture of a bit of P, a bit of C and some B, as well known as "Trafoöl" in the old days.
BTW3: One day I was playing around with a stepper motor driver however I killed a voltage regulator so it did no longer drop the voltage from 12V down to 3,3V but it was kind enough to deliver 12V instead. Because of the was the circuit was designed it did feed back that voltage to the 5V rail of the connected USB plug and back to my laptop - guess what ... It surprisingly survived. Man was I happy. I guess the docking station in the end saved my ass here.
So I hope you can get you power supply back to work in a short time, probably the display might be right and it does have in deed the ~58V and just beeing unable to regulate down because of a dead transistor acting as a linear regulator ... I'll keep my fingers crossed for you that it is that easy.
Thank you for your long comment. I never tried a Thyristor so I wanted to use one. and they are quite cheap compared to its capabilities. Not counting the damage, which I cannot blame the Thyristor for. And maybe I will find a way to replace the triggering relay by an optotriac or so. The relay was not in the main loop only at the trigger pin, so it should not be endangered. And the one of the primary side was protected by this 1-ohm resistor.
There are two versions of the same converter on AliExpress. Mine has a positive and a negative rail. The blown cap came from the negative rail.
Thank you for your offer (maybe we meet once if we live so close). I checked the datasheet of the BU508. But it says 8A peak collector current?
Concerning the rail gun. I corrected the title. I did not know the difference before...
At least I used a USB isolator to protect the PC. This would be a huge damage for me...
Concerning the power supply: I already got some help from my German friends (Datasheet and hits). So I hope I will be able to repair it. I also think it should be possible.
Great presentation. Thanks.
You are welcome!
Excellent project
:-)
Interesting video. Sorry for all the dead components in your lab.
I still hope I can repair the power supply...
Andreas Spiess sure, and perhaps make a nice video about the repair as well..
I'm sorry Andreas but I have been laughing hysterically at your expense since it's not only high voltages that cause such fun and games. Your escapade took me back to days at DEC when I was in Field Service and ended up literally blowing the tops off 4 memory chips by running +12v directly to them due to BAD instructions for a CSS (remember them?) board installation requiring a new wire wrap change on the backplane.
My face was saved when a support engineer came out to help and a further two chips blew before we went right back to basics and discovered that the problem was the backplane pin addressing in the installation instructions!! Oops! 6 chips blown, 6 chips desoldered and replaced and finally it worked! You not only have my sympathies but thanks for a massively entertaining (and funny) recount of your adventures to the dark side!
BTW I have that exact same supply and although I only use it at 100v and very low current for my purposes I shall be very wary if I ever use another for higher volts.
Yea, the old days with wire-wrapping. Did not hear this word for a long time...
I think, CZcams also has to be a little entertaining. So I try to add my 5 cents.
Great video. Reminds me of all the crazy stuff Ive done and blown up over my 4 decades of electronics creation.
:-))
I'm just cruising around the internet but the beginning deserved a like and subscribe! Thank you
Welcome on the channel!
awesome episode thank you so much
You are welcome!
One of the only channels that makes electronics fun without showing the presenter getting an electric shock each time. "400 Chinese Volts, if you know what I mean" - golden!
Thank you! But getting shocked is more successful ;-)
Hello!!! I love your videos!!! I wonder if we could use the coils to generate energy!!! I'm looking at what a wind powered coil generator would look like 🤔
I would google for Wind generators. Not easy...
You can use a feedback circuit using a tl431 ,some resistors, an optocoupler and mosfet to make the capacitor charging stops at 400V automatically.
what about making a repair video about repairing the power supply ? this could be the series pass transistor damaged
1. I used the ESP which should be ok because you also can change the max voltage.
2. Maybe I will do a repair video. Not decided yet.
Hi Andreas,
As an electronics engineer I'd like to suggest a few improvements.
1. Use an IGBT to switch the current through the coil. By using an IGBT you can precisely control the ON duration and optimize the firing power( As you said the current has to be switched off at the right moment)
Secondly, to drive the IGBT, Look for an Isolated IGBT driver and couple it with a single chip isolated power supply like the Murata MGJ1 or MGJ2 series.
This will make it extremely robust and give you better control over every variable. You can then control the current flow time in tens of microseconds and experiment to see what is best.
Finally, please do use a freewheeling diode. MUR460 or something would be alright.
Thank you for your advice. I am not yet sure I will continue with this project ;-) It is quite dangerous and costly.
You should put an optoisolator at the output of the resistor divider as well. Better safe than sorry!
And I’m sorry about your loss. Especially the power supply. On the other hand, you could try and fix it, and record a video of it. I love repair videos!
Anyways, at least you survived! That’s a relief!
1. I am not sure an optoisolator would help at the ADC. These devices are completely nonlinear. But a few more resistors in series would have been a better choice...
2. Maybe I will do a repair video. We will see...
Andreas Spiess Or an op amp in a voltage follower configuration. Make sure it’s rail-to-rail, though.
Nice video Andreas, One question: The voltage for the thrisistor to activate is constant? Ich danke dir sehr
Thyristors are triggered by a current, not a voltage. So the voltage is not so important as long as it is capable to source the needed current.
@@AndreasSpiess Vielen dank Andreas!
great video! i am trying to make a railgun of my own, but a railgun, not a coilgun. can i use the dc-dc converter alone to charge capacitors? or do i need to rectify its output?
A capacitor only can be charged with DC.
@@AndreasSpiess what about those foil capacitors made for ac?
@@king_james_official they are charged and discharged all the time.
The current is also limited by the charge time of the inductor. Use optoisolators or relays. Clamp input voltages from dividers using
You are right with the charge time of the inductor. I forgot to mention this one.
You're just like me. I like to dive into cool ideas without knowing exactly what I'm doing. I make dumb mistake and break a lot of stuff but I always have fun.
And I hope you learn something ;-)
Sometimes, but usually by accident.
I like the video and your comments make it fun to watch. My condolences on the part loss. Except for the large cap(firecracker?) from China, the others tried to put up a good fight. My thoughts on the voltage spike as I've had it happen to me on a few occasions are maybe try a tvss or a diode protection or some type of snubber? I lost a parallel port on my pc years ago thanks to HV, but I learned from it... MOCO30xx came in handy after that lol
You are right. I ordered a few MOC3051. Maybe they prevent the worst?
This channel is awesome
Thank you!
Thx for the experience!
You are welcome!
Thanks for this useful video, it has really helped me a lot!
Referring to about timestamp 12:30 where you placed the voltage divider: Have you verified that the power supply "in-" and the power supply "out" or 'gnd' as labeled on the board, are DIRECTLY connected? My cheap meter says so, but I really would like to be able to verify that they are directly connected by examining the board traces. It would be really useful to know for sure that they are directly shorted.
I do not remember. But you checked it with an Ohm meter and obviously, it is connected.
It was mentioned here before by other comments but for your safety you should always galvanically isolate your high voltage circuits from your low voltage circuits. Relays work fine and they make your final design mostly safe (besides the missing freewheeling diode) as long as the secondary side can handle 400V peak at the thyristor gate. What made me most nervous is the voltage divider. A brief search online for datasheets showed that typical 0.25 W resistors are only rated up to 350V. The worst part is when your setup works fine for a while and the 410k suddenly shortcuts your whole low power circuit will carry 400 V. When you have your hands nearby that could really be a problem :)
So rule of thumb: always galvanically isolate high voltage from low voltage circuits (or parts which are easily accessible by hand like connectors, buttons, etc.). Trafos, relays, optocouplers, galvanic isolators are fine if their voltage rating is sufficient (a voltage divider is not an insulator ;-) ). It it also not a bad idea to consider what happens if a simple component (resistor / capacitor) shorts out, especially when it is exposed to high currents/voltages. You don't have to consider every possible fault, just be weary what happens when a cap explodes or your voltage divider shorts out. If it is almost impossible to galvanically isolate, e.g. for the voltage measurement, just double up the components (e.g. two voltage dividers in series or replace each resistors by two in series so the divider can handle a single component failure) so that it will continue to be safe even if a single short circuit occurs in one of its resistors.
Be safe.
Thank you for your tips. I think a few things are done by now like two resistors in series for the voltage divider and a relay to trigger the Thyristor. But I am not sure if I will continue this project.
A sad tale but a great video. I too have managed to embed capacitor shrapnel in the roof or my shed through over-charging and it takes a while to get over the shock (& the tinnitus). Perhaps these could be used a form of weapon ? Or if the effect rather than destruction is the important thing then just some low-voltage pyros might be a safer choice.
I wanted to tell the story because I learned quite a bit here. And the journey was the goal of this project...
I knew about exploding capacitors but never experienced one before. And maybe they are a little louder at 400 V...
I love that you call yourself a noob
I am only honest!
Excellent Job
Thank you!
@@AndreasSpiess welcome !
5 BBBs. I earned the name Beagle Slayer. Learned about optoisolation. Made my first ones using IR emitter detector pairs. Needs lots of opacity. LED lighting seems to have plenty of IR output. Liquid electrical tape (several coats) works. But for $2 I found ready made ones.
You are right. Special optoisolators would have worked.
Maybe you could use a snubber network of some sort on that coil. That has to send a huge spike when it unloads.
You are right!
I started wearing goggles after a capacitor accident. It was a tiny one too. A little 25V like 10u or so and it was reversed in the circuit. I just happened to be reaching over it when it exploded and it popped me in the soft side of my arm and an impressive welt. And that was just a 25V 10u cap. At the time I also had a bunch of vintage 450V caps (I mess with vacuum tube amps) that I was reforming in a circuit I had built and I started wondering what it would be like if a 450V 22u cap blew and decided that maybe I'd stop being so cheap and buy modern caps and throw the vintage ones away.
Caps indeed can be dangerous (and the source of many problems). So it is always good to use the next better brand...
Fortunately I always wear goggles because of my view.
The optocoupler works well if you use a battery. The important thing to remember is that high voltage spikes can be created in the ground circuit, and if all of the ground points are connected to a common point this would not be a problem.
The normal optocoupler, unfortunately, was not able to trigger the Thyristor. I hope, the new Optotriac will be better for that purpose.
There is a reason that you had that problem it has to do with the current that is going to the gate from the optoisolator. The way to make it function is to discharge a small capacitor through the gate assuming the gate voltage is going to be about 3 volt and a small resistor such as 100 ohm in series with the gate so the SCR is not damaged. Use a 5 volt source to charge a 10 uF capacitor to discharge through the output of the optoisolator. I know this works as it is what I have used in the past for CD discharge to get powerful sparks out of a coil. That is with about 400v discharging through a ignition coil. Never lost any parts other than the resistor that I used to charge the discharge capacitor. For references on what I am saying look at the CD circuits for automotive use as an add on as a substitution of the points as was done commonly in the late 1960's in many of the hobby magazines of the time.
what is the Operating voltage of résistor used as divider?if you use a good quality resistor you'll be able to exceed 350v/résistor a bad quality max 100v and worst case under 100v.
You are right. I did not think about it. Otherwise, I would have used 4 in series. Next time I know...
How did you change the input voltage of the zvs390v circuit from 10-32v to 8v-16v?
I did not do anything. Maybe I had an older version.
At about timestamp 9:30 is when you talk about the input fuse blowing immediately. I don't see anything in the data (ebay description) that indicates the need for a current-limiting input resistor!
I just got a couple of these myself. Thanks to you, I ordered some 450V @ 10uF capacitors, which I will install before connecting (THANKS MUCH!). I'm not really sure about the input limiting, but, also thanks to you, I am ordering an auto fuse kit, which I can make good use of.
I wonder why the battery blew the fuse?
So good luck. These are very interesting devices, but also a little dangerous...
Ah man, LMAO !!. I love the dry humour. AliExpress will be happy. Loved the video. Thanks.
You are welcome!
Man ! You almost killed me from a heart attack when that capacitor exploded ! Hehehe ! Thans for sharing !
Please think about the capacitor. It is very dead now ;-) Much worse...
I enjoyed the video till the end, and celebrate your fine sense of humour.
Thank you!
The coils back EMF would have caused a massive reverse voltage spike that could have killed your esp8266 and thyrister. I think they usually put a reversed doide to short that emf out.
You are right. I have to add one.
The SCR gate current output while driving high di/dt circuits can kill a linear regulator by exceeding the output voltage of the power supply. Also if an SCR experiences negative gate current ( starved gate drive) during high di/dt operation this will destroy the SCR.
Perfektes Video 👌
Schaue deine Videos schon lange... sehr sehr gut und auf perfektem Niveau 🤙🤙🤙
Was sagt Great Scott zu deiner Version?? Kennt ihr euch?
Lg aus Österreich
Danke! Ich kenne Great Scott nicht, habe aber seinen Kanal abonniert.
You studied at ETH Zurich. Man that is impressive and also a nice video.
And hard ;-) Thanks for your compliment.
High VOLTAGE always brings some collateral damage :D ... Nice work done sir!
The coil is feeding energy back into the circuit when it's cut of. This results in a voltage spike. This is why you usually use a diode in parallel with a relay coil.
You are right. I have to enhance it!
Thank you very much.
You are welcome!
Can you please make a video explaining in detail how to make Great Scott's coil gun circuit
This is a topic of the past.
everything in life is a learning lesson. thank your for sharing. we see when it goes well but this tells us more, hope you gave them a proper burial
And the power supply is repaired by now...
I did something like this about 10 or 15 years ago. I used a PIC to generate a PWM into a charge pump to charge the cap to close to 400V. Instead of a triac or thyristor, I used an IGBT to switch the charge to the coil from a Ford starter solenoid. It worked but, like you, the concern of playing with 400 Joules of charge eventually awakened my common sense.
The parts are in a box for now. I ordered a few opto-triacs. Maybe I will continue later on. For the moment I had enough...
The Joule is a measure of energy, not charge ;P
Please consider an emergency discharge resistor for the capacitor! And you may should add a light barrier at the end of the coil to switch it back off
I will add a diode. The light barrier was not necessary because the discharge was very fast. It would be necessary for a second stage
Had the same thing happen to a pump start capacitor. Bought the pump from Craigslist. The previous owner had it running on 120V. I switched the coil connections to run 240V to pull less amps. Had to replace the cap as it was bad. Pump started and ran smooth, for about 30seconds. Then the smoke from the cap completely engulfed me.
Come to find out the previous owner had the cap installed incorrectly and was always engaged, even while running. He did complain the pump wasn't running as it should and I figured it was because of the faulty cap. The cap was rated at 120V, which was fine while he was running it. Since I changed the wiring, it was now delivering 240V through the cap.
Had to get another cap (which fortunately the local shop warranty exchanged the cap which was nice, but $10 wasn't bad if I needed to shell it out again). This time I verified it was wired up correctly. Fired it up, and pump ran smooth for well over 10mins when I stopped the experiment.
So you also had a learning you never will forget. The noise and smoke was aweful!
Yep. Mine was loud, per se. But it was definitely smokey. A really thick white smoke like a smoke grenade. I will definitely be checking wiring before I just assume it was connected properly. And the smell kinda gets up your nose and hangs around for a few hours. ugh
Will there be a repair video of the broken power supply?
Maybe, we will see...
Fascinating
As all dangerous things ?