Mr. Joules - when things fail catastrophically ;) - Page 1
Forum section: electronics / general

author: randomtronic
author_rank: Contributor
timestamp: January 26, 2017, 02:00:02 pm
content: Hi All,I made this contraption here:to test in a repeatable way what happens to grossly overloaded components.Here is a 20mm glass fuse getting annihilated:And for a comparison, uneventful selection of BS1362 fuses (HRC) which do their job:I am planning to test and observe more things, some out of curiosity and some out of anger, as time goes on.What do you guys think of my contraption?

author: Spuddevans
author_rank: Unknown
timestamp: January 26, 2017, 03:27:24 pm
content: Quote from: randomtronic on January 26, 2017, 02:00:02 pmI think it is very interesting. Thanks for sharing those. Post up some more when you make them.Tim

author: mmagin
author_rank: Frequent Contributor
timestamp: January 26, 2017, 04:07:00 pm
content: Nice wood prototyping! Interesting how even the fine copper wire blows the door open.

author: Ian.M
author_rank: Super Contributor
timestamp: January 26, 2017, 04:20:12 pm
content: As the caps aren't rated for pulse discharge applications you can expect them to puke their guts, develop excessive leakage or go Hi-Z sooner or later. Some way of monitoring the charging current would be useful so you can detect leakage. Also I would prefer it if it had perspex safety screens (with a hole for the 'idiot stick') either side of each of the clothespeg contactors, and a few more interlocks e.g. solonoid on the mechanical trigger mechanism so it cant be reset with power on, and a door switch on the test compartment lid that disconnects power and switches in a rapid discharge resistor.N.B Perspex/Acrylic can shatter - the test compartment lid should be Polycarbonate.

author: randomtronic
author_rank: Contributor
timestamp: January 26, 2017, 04:45:08 pm
content: Quote from: Ian.M on January 26, 2017, 04:20:12 pmThanks. You are right in what you are saying about interlocks and polycarbonate. I will upgrade this at some point, this was just what I had around. For the time being, I am being aware of the risks, and when I trigger it, I am wearing safety glasses and looking AWAY from it, in opposite direction (It is too scary to look at it) Then I review what happened through camera footage.The caps are definitely not rated for this, I know. But all of them are salvaged filter caps from teardowns, so when they do go, I can just replace them. Those are a bit like consumables here...Leakage can be noticed somewhat by observing the rate of discharge when not engaged, I think, so when it begins to drop quickly, I should know that some caps are busted

author: Gyro
author_rank: Super Contributor
timestamp: January 26, 2017, 05:23:01 pm
content: An excellent demonstration. (Though I agree with the advice about improvements for your personal safety). Using Photoflash capacitors would be a potential improvement but unfortunately they are only normally rated to 330V.I've been wanting to do a DC test on a BS1362 fuse for a while. I have a DMM which will only accept a 1 inch fuse on its lower current Amps ranges, so none of the standard SIBA ones will fit. I have a BS1362 1A fuse fitted but have always been a little concerned about how good its DC performance would be, so thank you.

author: Ian.M
author_rank: Super Contributor
timestamp: January 26, 2017, 05:56:14 pm
content: Add a 1N5913 3.3V 3W Zener in series with the charging circuit output, between the voltmeter and the cap bank, with a 30mA red LED + a 100R series resistor across the Zener and you'd have a pretty good indication whether or not charging is complete i.e. if the caps are going leaky. You might need to fiddle with a parallel resistor to allow a little leakage before the LED turns on.To detect if the caps are going bad you really need some way of instrumenting the discharge. Possibly a 10:1 attenuator for voltage across theD.U.T.cap bankand a high ratio current transformer made on a split ferrite core with a single turn primary and 100 turns of magnet wire into a 0.1 ohm burden resistor, then you could hook it up to a DSO in single shot mode and do some waveform maths to get the discharge energy.Edit: due to the two pole contactor, you cant safely scope the voltage across the DUT, even attenuated 10:1 without a high voltage high bandwidth differential probe, which will be $EXPEN$IVE.

author: Neilm
author_rank: Super Contributor
timestamp: January 26, 2017, 07:24:06 pm
content: In addition to your comments on glass fuse hazards, probing the mains could mean the plasma on the arc continuing to conduct for many cycles increasing the energy in the explosion.IEC61010 (the safety standard for meters) explicitally states that if you can mis-connect any leads for several functions all misconnections must be tested. It is to guard against the very thing. I have tested a very cheap multi-meter on this exact test. It blew the 50A breaker on the input to the lab and we found bits of the case scattered all over the lab.

author: Marco
author_rank: Super Contributor
timestamp: January 27, 2017, 12:22:24 am
content: Quote from: Ian.M on January 26, 2017, 04:20:12 pmCould you give some evidence or anecdotes to back this up?

author: Muttley Snickers
author_rank: Unknown
timestamp: January 27, 2017, 12:42:30 am
content: Well done, I like this stuff but as others have already mentioned perhaps some of the safety aspects could be improved upon particularly with all types of people viewing these videos, qualified and experienced people should know better in regards to risk and safety but some younger or newer viewers may not see all the potential dangers.I'm not sure if you are taking requests but could you also run a standard M205 glass fuse or similar with a free fitting heat shrink sleeve over it just for comparison against the one you previously did where the blast was not contained, I have a habit of doing this in some of my own equipment or gear that I have made which is mainly lower voltage stuff and generally pretty safe anyhow.Also I found this video the other day where it appears that some manufacturers are opting to do away with fuses altogether, I suspect they may have viewed your earlier exploding video and probably thought it was safer for the user, good on them for caring so much.

author: joeqsmith
author_rank: Super Contributor
timestamp: January 27, 2017, 02:36:41 am
content: You have built a bit of a death trap.It's a bit addictive isn't it?You may want to consider adding some sort of output network that will control the rise time, source impedance and the decay. With the line being AC, you may want to set it for something less than a half or quarter cycle.A faster camera would be a good addition. You may be interested in one of these:https://www.kickstarter.com/projects/1714585446/chronos-14-high-speed-cameraI offered to buy one of the initial prototypes before I knew his intent for them. I never saw anyone attempt to capture an arch like you are showing and I have my doubts it would be fast enough so I did not join the kick start.The following clip shows some of my tests. Normally, I can only supply up to about 20J.Have fun and be safe!

author: mtdoc
author_rank: Super Contributor
timestamp: January 27, 2017, 04:23:57 am
content: Quote from: randomtronic on January 26, 2017, 02:00:02 pmI like it. Well done.Looking forward to seeing more videos.

author: randomtronic
author_rank: Contributor
timestamp: January 27, 2017, 10:22:03 pm
content: Thanks Everybody for the replies!joeqsmith: Yes, there is this satisfying feeling...And yes, I would absolutely love to shoot this with Chronos. Unfortunately, even as inexpensive as it is for a high speed camera, it is out of my hobby budget by an order of magnitudeI like the idea of interlock on the lid, and the lid stronger a bit - I will most likely get this done soon. It is annoying having to fully discharge it when there is charge remaining, I think I can use small halogen bulb as a rapid high power discharge resistor ( I have some laying around)Muttley Snickers: Yes, I am open for suggestions on what to feed to Mr. JoulesHeat shrink covered fuse sounds interesting - I will definitely get this one done.For anyone interested in more videos like this - Yes, there will definitely be more. I started my YT channel about a year ago, and went through all stages from unwatchable to somewhat OK (I think) videos in that period of time. I find YT motivates me to do something interesting just so I can upload a new video. Before I started the channel I just sat on my behind procrastinating. So, please feel invited to subscribe to my channel to see more of my random videos (always electronics related) and help with my motivationAnd please drop in some suggestions what you would like to see in next Mr. Joules videos.Thanks again for the warm welcome

author: joeqsmith
author_rank: Super Contributor
timestamp: January 28, 2017, 03:45:36 am
content: That Sony I show was a big step up but no where near fast enough. Stick with what you have for now.I normally test with no cover but you are playing with glass and any time I do that, I cover the thing up. The big difference is you trigger yours with your hand. Mine is off a timer and I am no where near it when I play with the higher energy transients. I also have a long discharge probe with around a 6K resistor and an LED that I stick on the lines and across the generator before I do anything. The system is fairly safe in that it turns off the outputs but just in case.....For the discharge, I am using resistors. I have some small bleeders, 100M or so but the ones that control the discharge are pretty small in ohms. The last image in that video I show was a small 40W bulb. If you try a halogen bulb, make sure you cover that thing up before your try it!The one thing that sparked my interest in your video is that longer glass fuse you show. When it blew, there was a green glow. You see that same green glow at about 1:35 seconds on mine. This was the fuse that was in a VC99 meter, sitting in the meter...Some things I have thought about running are:See how many times I have to hit a MOV before it fails.Add a PTC in series with the same MOV and see how many times I have to hit it before it fails.Compare some caps that are rated for the AC mains compared with ones that are not.Many people post about counterfeit fuses and I have asked for a reputable counterfeiter so I could run their parts..PhotonicInduction has taken out all sorts of things with that large capacitor of his. That's way out of my league!!

author: MacMeter
author_rank: Frequent Contributor
timestamp: January 28, 2017, 07:21:24 pm
content: "I have asked for a reputable counterfeiter". Sorry, but this made me laugh! I know your intent, and love your well thought out videos!The subject of counterfeits and clones is a sore spot for me and I assume lots of consumers, and is basically out of control! For some products, it may just be the loss of your money, in cases of safety fuses, it's downright sinister and of course DANGEROUS. It would of course be welcome if there was a reputable source to BUST all the FAKE fuses on EBay, Amazon etc. but that would most likely be a full time job for a staff of people to attempt. And while it's not just the Chinese, though they may be the king of this sort of unsafe money grabbing, it has become an epidemic.Here's my little example. I know very little about electronics, but like many, I've used multimeters since I was a kid. I never thought much about their safety and internal fuses. Just recently I did a lot of homework on buying my very first decent MM. (I've used others Flukes etc. over the years). I opted for the EEVBlog BM235, and simply want to buy a few spare fuses, the original ones speced and used in the meter. Being a decent online shopper, I then found myself going down the rabbit hole. Prices for original fuses between $5-$45. Send up the RED FLAG! Hmmm, reputable sources, top dollar, EBay and some Amazon sources, bottom end prices. That price swing alone, made me realize that there is enough of a profit margin to be made, that the FAKES are most likely the reason. That alone makes buying QUALITY fuses more of a potentially dangerous proposition then it should ever be.I don't know if there is currently a viable solution to this problem, it would be a great fantasy to see all these counterfeit products being busted and outlawed, but that's just a dream, it seems.

author: nixfu
author_rank: Unknown
timestamp: January 29, 2017, 04:12:30 pm
content: This sort of thing just cries out for a real slow motion camera I think. That would be fun.

author: bktemp
author_rank: Super Contributor
timestamp: January 29, 2017, 06:39:37 pm
content: Quote from: nixfu on January 29, 2017, 04:12:30 pmYou could ask Dave to give it a try using the Chronos camera:https://www.eevblog.com/forum/blog/eevblog-947-chronos-high-speed-camera-review/21000fps (or 38000fps when the new firmware is ready) should be fast enough to make some nice videos. From my experiments the action happens in about 3ms for 6x32mm fuses and up to 25ms for 5x20mm fuses using 1500uF @ 350V. That should give at least 50 useful frames. The exposure could be a problem, because the initial arc inside 5x20mm fuses is extremely bright, saturating the first couple of frames. 6x32mm fuses are less violent.

author: f4eru
author_rank: Super Contributor
timestamp: February 01, 2017, 09:55:48 pm
content: Hello,When you say :QuoteThat's incorrect. The purpose of fuses is to prevent fire.To protect against electric shock, you need an RCD.Also, exploding fuses are not necessarily "bad fuses".Each fuse has a rating of rupture capacity, and in most application, this rating can be quite low.Explosion is not a problem if the fuse is embedded inside an equipment and this enclosure contains the explosion.

author: randomtronic
author_rank: Contributor
timestamp: February 05, 2017, 10:02:45 pm
content: Hi All,Thanks for all advice. I have upgraded Mr. Joules to v1.1I liked the idea of having interlock on the door - it is now in place, all it took was a micro switch and a relay. Now when the flap is open, a 30W halogen bulb is connected to cap bank for quick discharge, and at the same time power coming to HV generator is cut off. When I close the lid, bulb disconnects, and power connects to HV gen.The lid also has changed, not polycarbonate (don't have any... ) but I got some 4mm thick acrylic - i think it will do the job, but i still am cautious with this.Here is the update on Mr. Joules v1.1:And here, just for fun, is Intel Core i5 inside Mr. Joules

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: February 06, 2017, 09:17:11 am
content: Mistah Randomtronic I have a request. Please do a follow-up test of a glass fuse (m205 20x5mm) typeinsideone of those cheap ebay panel mount fuse holders like:http://www.ebay.ca/itm/New-Screw-Cap-Panel-Mount-Fuse-Holder-For-M205-5x20mm-Glass-Tube-Fuses-Case-/400736510659?hash=item5d4dc1e2c3:g:AEgAAOSwFAZTtLlBTo see if the blast containment is adequate. Also test of other styles of enclosed fuse holders would be appreciated, if you are looking for righteous things to blow up.On a personal note, I am trying to place your accent. It is as if a viking child washed up on the shores of East Anglia and was raised by localsheep shaggerspunters ***.The not knowing your back story is driving me crazy!***What? - it could happen

author: randomtronic
author_rank: Contributor
timestamp: February 06, 2017, 09:36:20 am
content: Hi chickenHeadKnob. You made me laughlol, no, i am not a viking, although you are not the first person suggesting this (maybe I should check my family tree?)Have a look here:https://www.eevblog.com/forum/chat/new-member-please-introduce-yourself/msg1022340/#msg1022340

author: randomtronic
author_rank: Contributor
timestamp: February 09, 2017, 11:17:04 pm
content: Quote from: chickenHeadKnob on February 06, 2017, 09:17:11 amI just ordered a bunch of those holders and some other ones with a couple boxes of fuses.I will post a video once this arrives

author: joeqsmith
author_rank: Super Contributor
timestamp: February 13, 2017, 12:30:46 pm
content: I would think in most cases where a fuse holder like this is used there is some sort of current limit in line with it. The fuse may not see a direct hit like it would for example with 10 ampere shunt like in a multimeter. Would a brand name fuse holder like the one shown with a glass fuse survive?

author: joeqsmith
author_rank: Super Contributor
timestamp: February 14, 2017, 11:58:49 pm
content: In the video where you run the 30mm 1A 250V fuse, I was not sure if that was a 3AG, fast or slow? I picked up some 20mm and 3AG fuses. Both fast and slow blow. Both 1A 250V. UL and CSA approved name brand. Also a name brand holder. Thought it would be interesting to compare results.

author: randomtronic
author_rank: Contributor
timestamp: February 15, 2017, 12:04:31 am
content: The big fuse was fast blow. I think thats why it worked ok. So far from my observations, the worst thing to put in multimeter is 20mm slow/time delay fuse. Guaranteed explosionI am waiting for more variety to arrive and will pop some more fuses. For the time being I am blowing up random stuffBtw. I was wondering if to post more exploding components here, what do you think? Maybe a separate thread, because its not only fuses, but still satisfying to watch

author: joeqsmith
author_rank: Super Contributor
timestamp: February 15, 2017, 01:18:44 am
content: I don't see a reason to start a new thread. Maybe you could rename the thread to something more fitting.I'm enjoying watching them. I saw your last two. The inductor was my favorite so far. I was surprised to see the Ferrite get damaged. It may be good to post the details of the new parts you run (fuse holders and fuses).I like the additional lamp to discharge the system. I do something similar where I always have a load. So, even if the leads are not connected to anything all of the energy is dissipated internally. If you continue to add capacitors, you may want to find something better to drain it down. The bulb may explode at some point. In my discharge probe, I think I have 10K or high voltage resistors. These are in parallel with another resistor and LED. The LED stays on to about 20 volts. I still strap the thing..Looking forward to seeing your fuse holder test! Stay safe!

author: joeqsmith
author_rank: Super Contributor
timestamp: February 16, 2017, 11:00:34 am
content: I played with some 20 and 30mm 1A fast blow glass fuses using a bench supply, car battery, the AC line and my generator. I tried running a panel mount fuse holder as well. Like you show with Mr Joules, the 30mm parts are more forgiving, sometimes.Looking forward to seeing your fuse holder test.

author: randomtronic
author_rank: Contributor
timestamp: February 23, 2017, 11:55:21 pm
content: Here is a fuse holder from ebay on request from chickenHeadKnob and joeqsmithI tried...

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: February 24, 2017, 12:06:50 am
content: Thankyou for going the extra mile on my request. I am some what reassured now as I use similar panel mount protection on my projects and am on wimpy North American 120v power grid.

author: joeqsmith
author_rank: Super Contributor
timestamp: February 24, 2017, 03:18:13 am
content: Subscribed. I was really not sure what to expect. Thanks for running it.Is there a Mr Joules 2.0 in the works?

author: randomtronic
author_rank: Contributor
timestamp: February 24, 2017, 06:34:44 am
content: Quote from: joeqsmith on February 24, 2017, 03:18:13 amThanks! No, there is no plans for Mr. Joules 2.0, but rather evolution as I go along. Eventually it will become 2.0 naturally, just have to see what mods will be necessary.I have another type of fuse holder coming, an inline type on a wire. It looks wimpy on pictures, might be interesting video

author: joeqsmith
author_rank: Super Contributor
timestamp: February 24, 2017, 12:50:57 pm
content: Quote from: randomtronic on February 24, 2017, 06:34:44 amSounds good. Looking forward to it.

author: CCitizenTO
author_rank: Contributor
timestamp: February 26, 2017, 04:04:01 am
content: Impressive stuff. Thanks to these videos I know why Dave makes such a big deal about HRC fuses over those cheap glass ones.

author: randomtronic
author_rank: Contributor
timestamp: February 26, 2017, 04:08:45 am
content: The rubber band is not in use anymore, i have changed the chamber door to "slide in" and added some interlocks. Have a look at the newer Mr. Joules in the playlist

author: CCitizenTO
author_rank: Contributor
timestamp: February 26, 2017, 04:24:44 am
content: Yeah I seen you upgraded to v1.1 and the slide on protection looks much more sturdy.As for components to put into Mr. Joules... I'd love to see some cheap binary logic gate DIP chips handle 400V and a ton of joulesI went to school for Computer Networking and they made us take some basic electronics courses. Of course one of the other students put one of the caps in backwards and blew it up... So being immature college kids we blew up a few more intentionally for laughs (because it's so easy to get them to fail catastrophically)

author: randomtronic
author_rank: Contributor
timestamp: February 26, 2017, 10:14:16 pm
content: OK, here is Mr. Joules episode from today: RFP12N10L MOSFET. Observe the sparks show

author: MacMeter
author_rank: Frequent Contributor
timestamp: February 26, 2017, 11:05:07 pm
content: Quote from: randomtronic on February 26, 2017, 04:08:45 amKnowing very little about electronics, all I can comment on is I LOVE the inginuity of the box. The use of materials one can find around the home is great. My favorite of course, the CLOTHESPINS, I'll miss the rubber bands. Well done. All I can suggest is save up for a camera that can capture at higher FPS.

author: Ian.M
author_rank: Super Contributor
timestamp: February 26, 2017, 11:35:10 pm
content: Actually I quite liked the rubber band, as it effectively allowed overpressure in the chamber to dissipate easily, though it could have done with a deflector round the sides, and IMHO the operating handle shouldn't be at the chamber end. The sliding lid design wont fail safe, and there's no way of telling how much blast energy it can actually withstand. e.g. a large Tantalum bead cap might be a little too exciting for itPersonally, I'd add a pullcord or other mechanical remote trigger mechanism so you can stand back + a plastic 45 deg mirror on a stand so you and the camera can look down into the chamber without being in the line of fire if anything fails.

author: randomtronic
author_rank: Contributor
timestamp: February 26, 2017, 11:45:41 pm
content: The chamber is not fully closed to relieve the pressure if present. The side towards the voltmeter is fully open, so if anything goes really bang, it should vent through there. The side towards the handle is solid, so should prevent any blast from heading that way.I honestly think it is relatively safe as long as I don't touch the wires directly. And during discharge I never look at it, but away from it (too scary) so if there is any debris, it will hit me in the back (I guess less important part than face...)I am worried for the camera sometimes, but its a distance away and zoomed in, plus it has a UV filter on, which is just a replaceable layer that would have to break before anything reaches actual camera optics.QuoteThanks for suggestion, I will look for one...

author: joeqsmith
author_rank: Super Contributor
timestamp: February 27, 2017, 12:27:24 am
content: My first generators, I was not too concerned about safety. The voltages started out pretty low and the energy levels were below 1J. This changed. I made my boxes out of 1/4" plate aluminum as I was concerned if the generators internals cut loose it may be worse than the meters.

author: randomtronic
author_rank: Contributor
timestamp: February 27, 2017, 10:48:34 pm
content: Hi All,Here is episode 13 of Mr. Joules's adventures: an in line fuse holder which refuses to blow up(perhaps because it's the 13th episode... )

author: Terrius
author_rank: Contributor
timestamp: February 28, 2017, 01:20:06 am
content: I'm impressed that these videos seem to prove that any fuse holder (even the super cheap ones) are better than just a bare fuse. Which I supposed should be fairy obvious, but it's a good bit of information for a newbie like me!Keep up all the destruction! Hopefully you can test out a small ceramic 20mm fuse soon!