Hunka Hunka Burning Love Posted April 25, 2016 Share Posted April 25, 2016 After seeing some people switch to a metal charging port cover and accidentally shorting out the contacts resulting in some damage, I've always wondered whether this was an isolated characteristic of certain EUCs. I checked my charging plug prongs on my generic EUC, and I was relieved to see zero voltage readings across the board. How common are live charging ports? Isn't this a potential child hazard where a curious toddler could easily remove the rubber cap and lick the terminals? Or even pets - curious dogs could get at it. I was surprised to see mentioned previously about people blowing up their charging port when they accidentally shorted the prongs. Metal cap thread Link to comment Share on other sites More sharing options...
MetricUSA Posted April 25, 2016 Share Posted April 25, 2016 I hope you don't have zero voltage reading, that is the battery you're reading! Children should not be around a motorized vehicles... Why is your pet licking your machine? Those metal tops should have rubber isolator pad in them, any smart person would realize not to short port out! Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted April 25, 2016 Author Share Posted April 25, 2016 I don't think there should be any voltage readings at a charge port on a EUC while it is off (or on!). It isn't a safe design especially when we are talking about higher voltages with high current. I think the guys who designed my board must have been smart enough to know that the port terminals shouldn't have live voltage across them when the EUC is powered down. I'll have to double check it when the unit is on... EDIT: Zero voltage when on too. It just seems fundamental to me that a charging circuit should have protection at that point. Maybe a diode would help? I'm no electronics expert, but I'm fairly certain the charge port on my laptop for example isn't live or else if that corner of my laptop were to dip into water there would be some fireworks. If you know what your pet or child is doing 100% of the time or can keep your EUC out of reach kudos to you. I'm thinking that anyone who has a live charging port may have a design flaw which likely is avoidable! But say you're charging your EUC and the ring on your hand touches the prongs inadvertantly... Things happen, and that's why UL, CSA, and CE certifications help avoid unfortunate accidents. Link to comment Share on other sites More sharing options...
jbwheel Posted April 25, 2016 Share Posted April 25, 2016 I have this problem on both pinwheel and gotway MCM4. As a consequence, if I don't plug the charger in the wall first then I would get a big spark while plugging the charger connector. And it is very annoying since I use a mechanical timer to charge my wheel. This also may be a problem under heavy rain I guess, not only because of pet or kids, especially when the rubber can be unintentionally removed so easily. Worst of all, my gotway charger have a plastic only connector which is too small so it is possible to plug it in a wrong way into the wheel... I guess this is just cost cutting since they labour price is getting closer to European countries. Link to comment Share on other sites More sharing options...
esaj Posted April 25, 2016 Share Posted April 25, 2016 If you can get a voltage reading from the charge port, likely the BMS doesn't have reverse voltage protection diode on the charging side. At least in older Gotways this seems usual. Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted April 25, 2016 Author Share Posted April 25, 2016 If EUC makers are following the threads here it would be prudent from a legal and safety standpoint to carefully examine this issue rather than have customers accept it as "normal" as I can see a huge number of problems with it. If a house burns down or some kid gets gets injured that may create a lot more issues than the savings incurred from using BMS boards without protection circuitry. Flashing LEDs, beeping / talking features and spinny wheels are going to be irresistable to crawling toddlers. And how oral are little kids? These EUCs are just one big soother/toy to them... Jewelry rings can be very conductive and electrical burns can be severe. Will the BMS cut off fast enough to prevent injury? If my el cheapo EUC doesn't have voltage at the terminal, why should a $1000 unit have a potential hazard? Link to comment Share on other sites More sharing options...
Chriull Posted April 25, 2016 Share Posted April 25, 2016 They could have done it - but did not (? in the earlier models?). The voltage is considered safe ( also DC is much "safer" AC)- especially not life threatening. According to the standards/legislation/safety rules a cap over the port is absolutely sufficient(imho). (By the way i am not in any way affiliated with any manufacturer/reseller/etc - just a user) By licking the charger one will (i assume - never really got in this topic) get burn marks - if an adult does this,he deserves it. If a child has the possibility, its the owners fault - he has to take care of his "toys" and much more of his kids. A small child playing with an EUC is much more endangered by accidently pushing the power button, imho. In every household there are many things, that could endanger small kids - its the parents responsibility to have an enviroment that is safe for kids. Just childs toys/"things" have to be in any way child safe - and there are still from time to time new problems/scandals... Rain will not inflict anything at the charge port - maybe some (a bit accelerated) corrosion over time. To see at least something you would need some extreme acid rain. Shortening the port with a (at least somewhat solid) ring should be no prob for the wearer - at least the rational part of my brain tells me this. But i am not 100% sure if i would dare to try it out... Maybe with a bucket of icewater aside, just on case... According the potential hazard possibility (overall quality) to price ratio i agree fully - it is not good. Although quite a part of the high prices for brand wheels come from quality batteries. We are still early adopters. EUCs are far away from mass production, and the design did not evolve over decades... E.g. Our parents paid ?about the same price? for their cars as we do (comparing income, inflation) and got nothing for it compared to nowaday cars. Our grandparents, if they could afford a car, payed a fortune for it and got real crap ... Edit: Stroke through a stupid comment - so noone could get the idea to prove it... ;( Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted April 26, 2016 Author Share Posted April 26, 2016 I've read some posts saying that if the battery temrinals are shorted together you have enough energy to weld metal. Remember those posts of photos showing what happens to the tips of multimeter probes that got disintegrated a centimeter or so? If that's the same energy at the charging port I would not advise anyone even with a bucket of water nearby to do any experiments! It's usually current that kills and not voltage so I wonder if there's enough in a battery pack to kill someone or at least cause some severe burns. You see videos of kids as small as 6 or 7 riding these EUC's. Can you trust that they won't have an accident or won't leave it lying where a sibling or pet might get to it? Dogs and cats will do the strangest things. If you've ever had a pet, you know what I mean! Now imagine a toddler still wet from a bath scoots away from mom or dad and makes a B-line for the EUC, pulls off the pretty black cap, and proceeds to lick or touch the terminals while standing in a puddle of water... There are somethings that you can't guarantee against, but if I were designing these products I'd ensure some basic safety protocols. To me having a live charging port is almost as bad as having a BMS that shuts you down at an unexpected moment. Are adults all to blame for that happening as well? In life you take some risks after weighing the benefits to be sure, but I think manufacturers have to step up and take some responsibility to prevent avoidable accidents. It just takes a few incidents to put EUCs into a bad light. Just look at all the problems with hoverboards... Link to comment Share on other sites More sharing options...
Chriull Posted April 26, 2016 Share Posted April 26, 2016 Voltages under 120V DC are considered as safe (ELV, Extra Low Voltage) for adults under normal conditions. For Voltages under 60V DC (SELV, safety extra low voltages) no touch protection is needed. 60V DC are considered as safe also for Kids and animals. 60V DC are also considered as save voltage for "wet-room" installations. You are right, that it is the current that kills - but in every "device" voltages are provided. So the regulations define voltages (different voltages for different enviroments like wet-room, kid-toys). So the EUCs with touch protection are adult safe, but i assume with just the cap on the charger port it cannot be considered kid-safe. (>60V) By a given resistance and voltage the current is limited. So even if an EUC battery can provide (very shortly) up to around ~80 Ampere (or even more) if shorted this amount of current can never flow through a human body by touching an EUC battery. DC currents above 140mA are considered as (possibly) deadly. Which (~<480Ohm body (DC) resistance would be needed) imho could be reached by soaking the skin with water (preferable with some additives as soap, bathing oils, etc..)... But it should be common sense to not mix water/bathing activities with electric devices. I am still not with you, that EUCs have to be toddler safe - they are not and will never be. The devices are to "unhandy" and way to powerful to ever be considered kid safe. So its still my opinion, that as not being a kids toy it is again the decision and responsability of the parents... I would consider parents, who leave an EUC on the floor with toddlers/babies roaming/crawling around unattended as irresponsible. Noone would ever leave e.g. ready for operation kitchen devices like blenders, mixers, etc reachable for unattended toddlers around... Also normal wall electrical outlets are considered "scoop-proof" and can be deadly for toddlers playing with nails, etc with an outlet... And there are no regulations or responsabilities for electricians or electricity providers to enhance the outlets in regard of "scoop-proof"ness to be kid-safe. Its again the decision and responsability of the parents to make the outlets child-proof. Anyhow - i am fully with you, that a reverse voltage protection diode or similar measures are an easy and desirable solution! And i think they are more or less standard by now for all the new (brand) models? Although i am not sure if this would change anything for the classification of the wheel. Link to comment Share on other sites More sharing options...
Gimlet Posted April 26, 2016 Share Posted April 26, 2016 A friend of mine got a very bad burn from his wedding ring when as an apprentice car mechanic he managed to somehow create a short circuit whilst removing a car battery. That doesn't mean that car batteries are dangerous, just that they should be handled with care. Allowing young kids to have unsupervised access to a euc is a bit like leaving your household bleach out or your kitchen knives for that matter. Link to comment Share on other sites More sharing options...
Chriull Posted April 26, 2016 Share Posted April 26, 2016 3 hours ago, HunkaHunkaBurningLove said: I've read some posts saying that if the battery temrinals are shorted together you have enough energy to weld metal. Remember those posts of photos showing what happens to the tips of multimeter probes that got disintegrated a centimeter or so? ... I'd remember that it was just the tip of the probe - so some milimeters. But @esajcan easily clarify this point. If really centimeters of a solid probe melted away i take everything back, what i said about shortening with a ring... I just remembered that there is NO overcurrent protection in the charging part of normal known BMS? In case of shortening the charging port one has to rely on melting cables/BMS components to cut the current - so sorry for my comment of shortening it with a ring - that was "thoughtless". I assume that also contradicts to the transport regulations (?UL-83?) which need battery packs to be short circuit proof? So protection diodes and/or more scoop proof ports like e.g. the ones used by ninebot (but they have quite "filigrane" pins) should be used... Link to comment Share on other sites More sharing options...
esaj Posted April 26, 2016 Share Posted April 26, 2016 1 minute ago, Chriull said: I'd remember that it was just the tip of the probe - so some milimeters. But @esajcan easily clarify this point. If really centimeters of a solid probe melted away i take everything back, what i said about shortening with a ring... On my probes, it was just the tip, but someone else posted a picture where the entire metal-part (usually a centimeter or two long?) was pretty much entirely gone after a similar situation: Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted April 26, 2016 Author Share Posted April 26, 2016 I'm thinking not many people would think an EUC might be dangerous as I never did until I discovered that metal cap thread and the guy needing to replace the port after accidentally shorting the pins with the metal keeper chain. Most electronics that I know of likely have a protection circuit in place as I bet one of the testing labs would be checking for this. I can't say for sure as I don't know their standards, but it just seems to make sense when the prongs are so accessible. Unless people read this thread I bet there are tons of people who wouldn't think to childproof their EUC from kids and pets, and it's a bit of a gamble since not all of them are affected. I hope I'm out to lunch with my concerns and an accident never happens because of this, and hopefully this thread will make people double check with a properly set voltmeter to see if they have an affected unit. I guess I think it's better to be in the know and be aware so one can take proper precautions rather than deal with the consequences after the fact. Link to comment Share on other sites More sharing options...
esaj Posted April 26, 2016 Share Posted April 26, 2016 It should be possible to add a power diode in-between the charge port & BMS by soldering it straight into the wire (and preferably wrapping it with a heat shrink tube so there are no exposed metal connections), but likely the charger would need to be adjusted to account for the voltage drop of the diode (0.6-0.7V for "normal" diode). And of course check that the diode can handle high enough forward current (more than your charging current). Need to test whether the diodes can handle the thermal load over longer time when charging big packs Quickly looking at my part bins, at least these would seem suitable (but remember, I'm not an electrician or electronics engineer ): SB100 (Schottky, 100V / 5A) Nope, too low voltage, the reverse voltage can climb closer to 140V or so 10A10 (1000V / 10A) For 2A or smaller chargers, maybe these could work too: 1N5408 (1000V / 3A) UF5408 (1000V / 3A) Rest of my "real" power-diodes (20-40A) are in TO-220 -packages, so not really suitable for placing between the wire There are probably many others suitable, afaik, just the reverse breakdown voltage must be high enough (200V or more should be fine?) and the continuous forward current must be high enough to withstand the charging current. And of course the diode needs to be put the right way around, so it's blocking current from flowing in "reverse" and not blocking charging Any electronics parts store probably carries suitable diodes, and the price is likely much less than a dollar a piece. EDIT: Here's a nice image of what I mean: Link to comment Share on other sites More sharing options...
Chriull Posted April 26, 2016 Share Posted April 26, 2016 1 hour ago, esaj said: It should be possible to add a power diode in-between the charge port & BMS by soldering it straight into the wire (and preferably wrapping it with a heat shrink tube so there are no exposed metal connections), but likely the charger would need to be adjusted to account for the voltage drop of the diode (0.2-0.3V for Schottky Diode, 0.6-0.7V for "normal" diode). And of course check that the diode can handle high enough forward current (more than your charging current). This could maybe lead to thermic problems. Power dissipation in the range of ~Watts, maybe not good vented and "sealed" in a heat shrink tube can easily lead to thermic overload... Best solution would be some kind of "active Diode" (realised with some low resistance Mosfet) -> so there is only a couple of mOhm in the charging path... But this cannot (really) be implemented just ad-hoc, imho. 1 hour ago, esaj said: ... There are probably many others suitable, afaik, just the reverse breakdown voltage must be high enough (100V or more should be fine?) Worst case should be 2*67,2V~134V if a charger with wrong polarity is connected. 1 hour ago, esaj said: and the continuous forward current must be high enough to withstand the charging current. And of course the diode needs to be put the right way around, so it's blocking current from flowing in "reverse" and not blocking charging Any electronics parts store probably carries suitable diodes, and the price is likely much less than a dollar a piece. EDIT: Here's a nice image of what I mean: ... Power dissipation capabilities should be easy to determine by experiment - i assume you have an constant current source for about 2A? Maybe you put a "normal" diode (heat-shrink-tubed) to some stress test and look from time to time how temperature evolves - or enjoy the smoke signs Link to comment Share on other sites More sharing options...
esaj Posted April 26, 2016 Share Posted April 26, 2016 6 minutes ago, Chriull said: This could maybe lead to thermic problems. Power dissipation in the range of ~Watts, maybe not good vented and "sealed" in a heat shrink tube can easily lead to thermic overload... Best solution would be some kind of "active Diode" (realised with some low resistance Mosfet) -> so there is only a couple of mOhm in the charging path... But this cannot (really) be implemented just ad-hoc, imho. The active device idea is nice, but how do the BMSs then do the reverse polarity protection? Is there an actual diode or some circuitry with a mosfet or such? 6 minutes ago, Chriull said: Worst case should be 2*67,2V~134V if a charger with wrong polarity is connected. Good point, that probably rules out Schottkys, or at least I don't know of any that has a reverse breakdown voltage above 100V. 6 minutes ago, Chriull said: Power dissipation capabilities should be easy to determine by experiment - i assume you have an constant current source for about 2A? Maybe you put a "normal" diode (heat-shrink-tubed) to some stress test and look from time to time how temperature evolves - or enjoy the smoke signs Yeah, I have home-made adjustable constant current source, that goes up to 6A (but don't know if it can really stand that, depending how much voltage the mosfet needs to drop, the power dissipation could be pretty large and it has a fairly small heatsink ). I'll have to see if I get the magic smoke out from those smaller diodes. I plan on building a bigger version with multiple mosfets (and 4mm thick aluminum bar across them as heatsink ) for adjustable electronic load usage. The schematic's here: With some additional notes & changes in the below posts Link to comment Share on other sites More sharing options...
esaj Posted April 27, 2016 Share Posted April 27, 2016 Ok, I did the (first) test with a 3A diode. I picked UF5408 (simply because I have most of those ), here's the datasheet, if anyone's interested: http://www.vishay.com/docs/88756/uf5400.pdf To start off, I soldered some wires to the diode: Then cut the excess off the legs, applied some 5mm heatshrink tube around it and measured the forward voltage drop: 0.511V with minimal current flowing through it (it goes up with the current). My multimeter's a cheap supermarket-one, so better not trust those final decimals too much The board in the left is my constant current source. I initially tested things a bit to check that I get enough current etc, and then let the diode cool down. The diode was powered through a 5V output from a computer PSU, I used lower voltage so my constant current source wouldn't have to drop so much over the mosfet (AFAIK, it shouldn't matter with the results, as the power dissipated by the diode is the forward voltage drop times current). Ambient temperature was around 24.5 degrees, and when I fired up the power. I used a handheld infrared surface-temperature meter to check the temperature, but I wouldn't call the results exact, because it isn't actually meant for measuring such small devices, and I'd get slightly different results trying to measure from different directions. Within a span of few tens of seconds or so, the surface temperature of the diode was above 50 degrees Celsius. Fifteen minutes later I was getting values between 60 and 70 degrees Celsius. I measured the temperature (roughly) every half an hour or so from there on, and it kept steady around those values. At some point I measured the voltage over the diode, which was pretty much spot on 1V (something like 1.024 or thereabouts, didn't write it down). Somewhere between second and third hour (I kept it there for 3.5 hours in total), I noticed that the current had dropped (the constant current source was showing 1.8 for reading) and when I measured the voltage over the diode, it had gone up to around 1.3V: The temperature readings were still between 60 and 70 degrees. After 3.5 hours total, I powered down, the diode cooled to room temperature within a minute, and tested the diode forward voltage and reverse voltage. Slightly higher forward voltage reading than before, don't know if it's a sign of damage or just "normal" variation. It did still block in reverse normally. Don't know for sure how much conclusions can be drawn from here. Apparently the diode still works just fine, and although it reaches temperatures where it will burn your fingers if you try to hold it (I tried, couldn't do it but for a couple of seconds ), it seems to reach an equilibrium and stay there. Not sure why the forward voltage raised in the middle (and dropped the current), that could be just some effect of the temperature OR it could actually mean that it was somehow damaged. In conclusion, I'd still say it's possible to add your own reverse protection diode in the wires if you want to/need to, but probably better go with the higher amperage versions (like 10A), as they're rated for higher currents and also (at least from the ones I have) are physically slightly larger than the lower current ones, hence more surface area to shed the heat. EDIT: Just for the fun of it, I'll try later taking the current up to something like 2.5A or closer to 3A... let's see if the magic smoke comes out Link to comment Share on other sites More sharing options...
esaj Posted April 27, 2016 Share Posted April 27, 2016 Looking at this picture, I found the reason for the "rising" forward voltage drop: I was working and doing this on the side, so I wasn't really paying that much attention, then when I saw that the current had dropped and measured the voltage, I measured it wrong I'm actually measuring the voltage drop over the diode AND the constant current source. But it's a 5V line, why is there only 1.3V drop? I tested that the calibration of the voltage displays (the ones in the constant current source, showing amperage as 1V = 1A, see the schematic-posts for more in-depth explanation) against the multimeter, and they seemed correct. I then measured the output from the ports on the PSU, 5V as expected. 4.7V at the banana plugs. 3.6V at the alligator clips? Seems that the cheap & crappy banana plug/alligator-wires I got from Aliexpress make bad contact and drop voltage... Link to comment Share on other sites More sharing options...
Chriull Posted April 28, 2016 Share Posted April 28, 2016 19 hours ago, esaj said: Ok, I did the (first) test with a 3A diode. I picked UF5408 (simply because I have most of those ), here's the datasheet, if anyone's interested: http://www.vishay.com/docs/88756/uf5400.pdf ... Ambient temperature was around 24.5 degrees, and when I fired up the power. I used a handheld infrared surface-temperature meter to check the temperature, but I wouldn't call the results exact, because it isn't actually meant for measuring such small devices, and I'd get slightly different results trying to measure from different directions. Within a span of few tens of seconds or so, the surface temperature of the diode was above 50 degrees Celsius. Fifteen minutes later I was getting values between 60 and 70 degrees Celsius. .. The temperature readings were still between 60 and 70 degrees. After 3.5 hours total, I powered down, the diode cooled to room temperature within a minute, ... Don't know for sure how much conclusions can be drawn from here. Apparently the diode still works just fine, and although it reaches temperatures where it will burn your fingers if you try to hold it (I tried, couldn't do it but for a couple of seconds ), it seems to reach an equilibrium and stay there. 60-70°C in an open air space (free air convection possible for cooling) should be way to much, to put the same stuff into a closed compartment. I am quite sure that the same diode will go up in smoke when you make the same test and put the diode in a box (something not burnable, i would suggest )... Quote ... but probably better go with the higher amperage versions (like 10A), as they're rated for higher currents and also (at least from the ones I have) are physically slightly larger than the lower current ones, hence more surface area to shed the heat. EDIT: Just for the fun of it, I'll try later taking the current up to something like 2.5A or closer to 3A... let's see if the magic smoke comes out I am not sure if a diode with higher amperage/power specification will help - one still has the same power to be dissipated and cooled. Since this happen in a more or less closed compartment it will tend to end in the exactly same result? With a power diode it takes maybe a little bit longer... Imho the only solution is to choose a diode with less forward voltage (reduce dissipated power) or introduce some effective cooling... 18 hours ago, esaj said: ... I then measured the output from the ports on the PSU, 5V as expected. 4.7V at the banana plugs. 3.6V at the alligator clips? Seems that the cheap & crappy banana plug/alligator-wires I got from Aliexpress make bad contact and drop voltage... Wow - impressive numbers for a "connection"...;) Edit:Just remembered that in cranium identified the "reverse polarity protection" "thingie" from the Ninebot BMS. " There a couple of other transistors at the +Positive lead for the charging cable that are completely unmarked. This prevents current flowing out of the battery from the charging port. The ground and source pins are both on the charging cable +Positive wire. " Seems to be somehow an implementation of "active diodes" or paralleled high power "special purpose" diodes? As your experiment imho leads to the conclusion that with a "normal" diode this task cannot be accomplished? Link to comment Share on other sites More sharing options...
esaj Posted April 28, 2016 Share Posted April 28, 2016 20 minutes ago, Chriull said: 60-70°C in an open air space (free air convection possible for cooling) should be way to much, to put the same stuff into a closed compartment. I am quite sure that the same diode will go up in smoke when you make the same test and put the diode in a box (something not burnable, i would suggest )... I could try that later on, if I find something suitable to work as an enclosure. I wouldn't suggest putting the diode in the battery or mainboard compartment or near anything heat-sensitive, but surely there's some place in the shells where the charging wires run somewhere where it won't matter (at least in most wheels). Then it should be just a question whether the diode can handle the heat up. 20 minutes ago, Chriull said: I am not sure if a diode with higher amperage/power specification will help - one still has the same power to be dissipated and cooled. Since this happen in a more or less closed compartment it will tend to end in the exactly same result? With a power diode it takes maybe a little bit longer... Imho the only solution is to choose a diode with less forward voltage (reduce dissipated power) or introduce some effective cooling... Yes, it will still burn off power as heat due to the forward voltage drop, larger diode would just have more surface area to get rid of the heat (which will then still of course heat up the surroundings), so the diode itself shouldn't fail as easily due to overheating. If there are Schottky-diodes with high enough reverse breakdown voltage (>150...200V?), they would (more than?) halve the dissipated power. 20 minutes ago, Chriull said: Wow - impressive numbers for a "connection"...;) Yeah, they're supposed to be conductors, not resistors I tested with another set of cables (with proper connectors), very little if any voltage drop. Then took the amperage up to 2.5A, but now that the mosfet in the constant current source had to drop more voltage (as it wasn't being dropped as much by the cables/connectors anymore), it actually went into thermal shutdown after a while (well, at least I now know my overheat-protection circuitry works ). So couldn't really test it for a long while with higher amperages (seems I can't get much more than 2A with the crappy wires). A quick back-of-the-envelope -calculation suggested that the mosfet was dissipating around 9-10W... Need to build a "proper" constant current source/adjustable electronic load with paralleled mosfets & better heatsinking Link to comment Share on other sites More sharing options...
Chriull Posted April 28, 2016 Share Posted April 28, 2016 5 minutes ago, esaj said: ...Yes, it will still burn off power as heat due to the forward voltage drop, larger diode would just have more surface area to get rid of the heat (which will then still of course heat up the surroundings), That is my point - if in a (small) closed compartment power is dissipated and turned to heat the heating up will be more or less equal. Maybe some small change caused by the diode volumina. (The bigger diode introduces a bit more thermal capacity that has to be heated up) 5 minutes ago, esaj said: so the diode itself shouldn't fail as easily due to overheating.... The final temperature for the semiconductor to die is more or less the same for quite every diode? With the bigger semiconductor the power diode will maybe just need a little bit more "push" to finally blow. Very Imho. If you find a nice enclosure and have a spare power diode with quite similar forward voltage to go up in smoke we'd have a practical evidence... Link to comment Share on other sites More sharing options...
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