Why Replace Bulging Electrolytic Capacitors

hi do you have a wall adapter or power supply that doesn't output right it turns on and off or can't maintain its voltage it's likely the damn electrolytic capacitor in it if you watched my videos you know electrolytic capacitors can blow with a B oh they have to be connected to a circuit to blow up but they don't always blow up I want to see what happens to them when they half break let's half break one okay I have a tiny electrolytic Capac capacitor and I'll half break it in an accelerated fashion by connecting 120 volt AC across it don't try this experiment U these capacitors typically half break over a lifetime of usage but I don't have that kind of time so uh I'll over voltage it until it half breaks just a quick touch well this is a very familiar mode of failure around this neighborhood where excess overload results in capacitor elimination this is a total failure when I say half failure I mean the capacitor is still capacit but it is capaci thing at half its capacity capacit is not a verb it's like when you add or to a verb inductor inducts collector collects Mentor Ms me is not a word when I hired you as my writer I thought you could English I can English just fine anyway a half capacitor still still works but havely let me draw this for you a capacitor is made of two conductor plates side by side separated by a non-conductive isolating layer called a dialectric and charges are stored on its plates the wirings inside a capacitor have their own resistances we show as a very small equivalent series resistance or ESR also even the best dial electrics can leak very little current that we can show as a super large resistance we always ignore it so large like gig ohms and then we have polarized capacitors like electrolytics that the dialectric is such that it acts like sort of a diode I explained all these in my video about capacitors but any part of a capacitor can degrade causing a less capaci capacitor it's not a w I have a brand new 60 volt 40 amp power supply and my capacitor is rated for 16 volts but I place it in reverse polarity and if I increase the voltage at some point it starts conducting current and the capacitor will slowly heat up you see oh there you go it's starting to conduct it's almost one watt through the [Music] capacitor I didn't even see it bulging I guess it's like a pressure cooker the dialectric gel in these electrolytic capacitors boils and the pressure builds up until it blows up I just want to half break a capacitor I guess I have to let it cook slowly so I just give it enough voltage for a little bit of current so that it doesn't blow right away and I just put it on the side and let it get damaged over time now while the cap is cooking did you see Elon musk's latest announcements that a person with neuralink brain implant can move a computer mouse with their thoughts is that good or bad to understand it better I used articles from my sponsor ground news this platform was created by a former NASA engineer they collect news articles on any topic from all around the world so you can compare coverage in a scientific datadriven way to get the full picture check them out at ground. news/ electroboom on this subject they have over 150 articles so we can see a spectrum of reaction one calls it Nobel Prize worthy while the other worries about the risks of having a chip in the brain not only can you get the information from all sources but also ground news reports on where they stand on the political Spectrum this makes ground news such a valuable service because knowing the existing biases In Articles makes it easier to get to the truth and avoid censorship and misinformation which is why I'm a fan of ground news and there you can also follow your interest for the latest updates I use the Vantage subscription for unlimited access which you can get at 40% off using my link if it wasn't cheap enough already or try their startup plan for just $1 this month and keep yourself well informed and support a team who's working to make the media more transparent it should be well cooked oh you know the issue with tiny capacitor is they don't have pressure release mechanisms but bigger power capacitors have it because the explosion can be catastrophic so they have for example these tiny grooves on the top plate this is a healthy 2200 microfarad capacitor with an ESR off around1 ohms and the parallel resistance is over 6 megaohms so when I overload the capacitor and it bulges those tiny grooves on the top break open allowing the release of the pressurized gases and this will save the W stop it I guess this is a much smaller explosion compared to what could be I'm pretty sure this is a half blown capacitor now measuring the parallel resistance oh it's well over 11 Mega ohm now well the good thing is that the plates are not shorted so it should still be able to to capacit the capacitance now is only around 420 microfarad dropped way down from the original 2200 microfarad and the ESR now is 1.1 ohms over 10 times what it was before I mean it takes a lot of talent to be able to half break a capacitor after how many minutes now so it is still a 420 microfat capacitor but it is capacitating much less than before still not a ward the low capacitance and higher ESR is a problem for almost every Power Supply where the circuit takes the input energy and pulses the energy into the output and the capacitor's duty is to absorb those pulses and create a constant output like a switching inverter or a full Bridge rectifier here I have a full Bridge rectifier with its output hooked to a capacitor and powered from an autot Transformer so we can provide a safe lower ac voltage we just have to go always reduce your Supply's voltage before hooking your circuit up to it so here is the rectified DC voltage with a 100 microfarad capacitor if I connect a resistor to it as a load we see it is repelled because during the off periods of the dials the capacitor discharges into the resistor trying to keep the voltage up until the next wave of input charges it back up but if I connect a smaller 10 Micro capacitor to my circuit let alone the higher ESR with the same load the capacitor discharges so far it can reset circuits constantly so anytime you see a BGE capacitor you should replace it with preferably better parameters so they won't degrade the same well I did have a problem with this wall adapter here which supplies to all my security cameras and all my cameras were turning on and off I cut it open and low and beh hold it was a bulge capacitor I replac the capacitor with a higher rating capacitor and it's been working since now that we know all this let's repair a broken power adapter together this also doesn't output voltage looking at the circuit capacitors they all look fine so I guess we are stuck with 100 other possibilities let's plug it in and measure the output voltage there is nothing is there burn mark on this way always disconnect power before touching a circuit always make sure the circuit's high voltage capacitors are discharged before touching the circuit just welded okay so there are a few input filter components the rectifier and its capacitor let's measure the voltages around 115 volt AC input around 160 volt rectified DC so all seems good there must be the controller circuit they are using OB 2269 I found the data sheet of the chip why does it even say confidential if it is available to public so this control chip powered by the rectified voltage provides a pwm signal to this mosfet that switches the primary of this Transformer creating a smaller output voltage here that is rectified into DC the output voltage is sensed through an op the coupler back to the chip so it can tune the pwm duty cycle to find youe the output voltage for some reason the supply voltage to the chip is zero I wonder ah look the chip supply line is shorted to ground which means the control chip is broken it didn't die a natural bulging death you know this was my raising desk power adapter and died while I was swinging my high voltage magic wand around some good size ARS jump from this thing eh zap you zap you oh apparently I killed Electronics in my adjustable table no problem replacing this chip is no problem for me we just need to find the replacement it's nowhere to be found except Amazon where I can get 10 pieces for $11 and receive it after a month I just need one of them though maybe I should get 100 pieces for $22 and throw 99 of them into garbage but that single one will be 22 cents a brand new wall adapter there is like $20 so I save $9 if I just replace the part waiting for a month spending my own time it's just sad that all these perfectly good components have to go into the garbage well not for me I shall keep this in a bean of potentially useful Parts potentially never use it so after my decease my descendants would have to deal with the horde of garbage I shall collect over years and send me their curses to add kindling to the fire I'm burning in thank you for [Music] watching

Channel: ElectroBOOM

Views: 1,079,479

Keywords: educational, electrical, ElectroBOOM, science, electronics, engineering, entertainment, equipment, measurement, experiment, mehdi, mehdi sadaghdar, arc, mishap, physics, Sadaghdar, test, tools, circuit, funny, learn, shock, spark, discharge, decay, degrade, electrolytic capacitors, bulging, power supply

Id: 66Z0NINGfa0

Length: 11min 19sec (679 seconds)

Published: Fri Mar 15 2024