Magnasine MS2012 Inverter Charger Troubleshoot and Repair

Probably the most repair information on the internet about this inverter, charger. See the entire troubleshooting procedure. This unit had an internal NTC fault. See the cause, plus a lot more. Find out how the processor (MCU) controls the fans with external PWM, and see how it determines temperature related faults with the transformer and FET's.

[@unlokia]

A *PROPER, PROPER* ELECTRONICS ENGINEER IS WHO YOU ARE WATCHING HERE!

[@Billblom]

A lot of EE's can design things, but can't troubleshoot worth beans...

[@MrLRankin2]

@@Billblom That's been my experience. This guy, however, can.

[@jlucasound]

I have never met anyone better. I worked for iRobot. Equal, maybe.

[@DAKOTANSHELBY]

For a minute I thought you were going to have to accept the oem fan and control logic, but I chuckled when you admitted that was not acceptable then you proceeded to introduce a new design that worked with the more superior higher quality fans. Thank you Mr. Carlson! Viewing from Greater Chicagoland

[@ivangutowski]

The second the video loaded, I looked at all the equipment and thought - well if this guy can't fix it then no-one can :)

[@Texaca]

...it looks like the lab to the beginning of a Mad scientist 🤣

[@sdscotto]

I've learned more from you, Alan (W2AEW) and Dave (EEVBLOG) in the last year, than I have in my entire 51 years of tinkering! Please keep the videos coming!

[@MrCarlsonsLab]

sdscotto Thanks for the nice comment! Alan and Dave are great guys!

[@MrLRankin2]

Me too!!! I didn't know diddly squat about tubes until I found this channel though. I was starting to believe that no one tauight tubes anymore.

[@AW-Services]

I love watching these videos. There is nothing that challenges Paul. I really like the " I'll build something to solve it " attitude

[@accidentalheadclunkers8517]

The extra excitement, knowing you're doing this for someone important to you is obvious in your voice. 👍

[@DougHanchard]

If there's an analogy that fits Paul really well; Carlson is the Top Fuel Drag Race Champion of Electronics Hot Rodding. There's no one else that comes close to reverse engineering something, knowing what *could* work - and then just doing it. I'd hate to see some 'drag race' tech inspector keep up with the mods Paul could do. And he's already built an EGR black box for his T/A. I wish he could make a Hot Rod Three Phase Power supply that could be made for a Bridgeport milling machine that many were configured with 550 V power (bloody Brits) that requires a super expensive Rotary Phase converter that could be done for a fraction of the price. Then, Canadians would be able to bring back some old school machinery back to life in country farm shops that don't have anything else other than Single Phase 220V. I've seen lots of 'home made' 3 Phase rigs and Static 3 Phase.... but man... do they look scary. This is a project for Mr. Carlson to show us how it can be done safely and smartly. Maybe with a Variable Frequency Drive 'option' switch and .... okay okay, I'll shut up now. Really enjoyed this video and how you broke down how to diagnose, fix, hot rod / modify and make something better than when it left the factory. I learned a lot in this (now) 3 year old video. Thanks for taking the time to make it.

[@pwrouzaud]

When my inverter went out I was kicking myself for never learning this stuff. Now that I revisit it, I know why! Some people got it, some don't. You do. Thanks

[@Texaca]

...it's just Boolean Logic and Ohms Law 😄 ...but I know what you mean, and I studied electronics at a vocational school, Electronic Engineering technology, I wasn't good at board level troubleshooting 🤔

[@kennymanchester]

I love that you not only understand and repair things, you frequently improve them and make them better! All while sharing your thought process along the way. So appreciated.

[@MrCarlsonsLab]

Glad you're enjoying Kenny!

[@dash8brj]

The transistor mounted right behind the heatsink on your pwm correction board is in that spot for thermal tracking. Its done often in power amplifiers, particularly RF power amplifier bias circuits :)

[@maddog9659]

I have been absolutely humbled after watching your videos, just discovered your channel about a week ago, took electronics in college and never did anything with all; that knowledge, I am honored to learn from you and your videos are extremely educational, would love to see you troubleshoot repair and possibly modify car audio amplifiers..

[@z1power]

Man, every time one of your videos start, I sure hope you are not in that room during an earthquake!!

[@skoshorek]

Thanks for this education! As an old, retired, mechanical engineer I know just enough about electronics to be dangerous. When I went to college we still used slide rules, since the TI calculator wasn't invented yet. I'm the guy you were repeatedly warning to "proceed at my own risk". My motorhome's MS2000 inverter started shutting down due to a temperature fault on my way to Arizona for the winter. I did enough troubleshooting and guessing to point to the fans as a likely culprit. It could also be the fans' control system, but that would probably require a trip to a Magnum repair site. Once in Arizona I rigged an exterior fan and determined that the temp sensors were operating reasonably; giving changing temperatures as the unit operated with the exterior fan on and off. I am planning to dig into the inverter today to replace the old fans with the two new (expensive) fans that I got from a Magnum repair site, I looked at much cheaper fans online, but wasn't sure they would work, and your video confirmed my suspicions were well founded. I watched your video all the way through in one sitting and learned alot about how my inverter works. I wish my college professors taught as well as you do. I enjoyed learning about the MTU, how thermistors operate, how to trick the fan controls to think the temp was changing, and on and on. I would not trust myself to do most of what I learned on my expensive equipment due to my poor soldering skills, but it made me think that if I was starting out again I might choose electronics as my chosen field. Your handmade circuit board for the improved fans was especially impressive to me. Sorry for the long post, but I'm probably not your targeted viewer, and I wanted to let you know how much I enjoyed your efforts. Now to go outside and rip into this job. If the new fans don't completely solve the problem I'll be hauling the inverter to the Magnum repair site with my credit card.

[@MrCarlsonsLab]

Glad You found the video enjoyable! I really don't have targeted viewers, the goal of this channel is to share knowledge. Good Luck!

[@davecc0000]

Excellent Paul! Great to see that sometimes even a complex piece like this can be due to a stalled fan... Stellar design of the pwm filter. And thanks for the introduction to DR fans.

[@MichaelLloyd]

I look forward to your videos more than my mom looked forward to her soap operas back in the late 60's (that's a compliment lol) Well done as always. The attention to detail is much appreciated

[@MrCarlsonsLab]

Michael Lloyd Thanks Michael! Already have the next planned.

[@hendrikhendrikson2941]

This apparatus is now better than factory new :) Thank you for this informative video.

[@james5553]

Brilliant. Once again I find myself learning new skills quickly due to your practical approach to teaching. Great work - from a physics and chemistry teacher!

[@MrCarlsonsLab]

Thanks for your kind comment James!

[@pstoneking3418]

Excellent job, refreshing to see people on KZbin that know exactly what they are doing and have the ability to explain what was done, so others can understand what was done.

[@yngvai777]

I recently started working as an industrial electronics tech, your videos have helped me tremendously and have given me a lot of confidence at work. Thanks a lot for these videos.

[@MrCarlsonsLab]

Glad these video's are benefiting you Michael! Thanks for stopping by.

[@Wtfinc]

really? where? I want one.

[@juanabreu5127]

Sir, two channels stand over the crowd: Mr Carlson´s Lab and TRXBench. I´m more than pleased to watch them. Bless you.

[@MrCarlsonsLab]

+Juan Abreu Thanks Juan!

[@-HustleUnion-]

that is some top quality work you just don't see everyone do. when you take pride in what you do and are very good at what you do, this is the result. i hope one day to open up something to see a Mr Carlson written on the board.

[@fibrodad1354]

I love your videos, i had to rewatch them though while waiting for this one, i do hope you teach in your non youtube life as you have a natural talent for teaching. Thank you Mr Carlson for giving us your time.... thumbs up from me.!

[@MrCarlsonsLab]

JRushPixel Thanks for the nice comment!

[@samtzam3774]

The Darlington configuration needs to had also temperature match. So as result is the transistors had identical changes to Hfe at the temperature changes.

[@MrCarlsonsLab]

+Sam Tzam You got it Sam!

[@BatGS]

Correct. I figured he did that and did not mention it. In some ways he narrates if the viewers R 'dummies' and other times if we R experienced techs. I suppose the average is acceptable. All due respects.

[@gunlover1955]

I am new to your channel and all I can say is you are very competent with your skills, I am learning a lot from the videos you have made Thanks. I hope you keep putting new stuff up for everyone to see. I loved the fan control board part.

[@rhyoliteaquacade]

Fascinating repair project. Thanks for the detail and process.

[@damuelkohlberg890]

This is by far the most amazing and satisfying middle finger to the proprieties market marketing practice of the hi end super expensive technologies companies. A definite favourite to watch. You are my hero Mr Carlson. I have had some very trying experiences with a trace inverter and as I have a limited budget and it is often the only means to the 21st century, way out here in my corner of Oregon. The price of repair; by the frequency demanded and certainly not by measure of the quality of the device or its components, is unmerited and in my opinion an act of extortion. The worst part being that as a result of the 4000 dollars initial price it does not seem practical it to ditch over three hundred dollar repair bills. F.M.L! but this made me smile. Keep up the awesome work. I hope to see more with your patrion videos as well. :)

[@NicholasMaietta]

Thank you for being a great human being and sharing your knowledge. I very much appreciate this.

[@frankkoslowski6917]

Thermal Drag? Something which was probably not covered during one's apprenticeship as Precision Instrument Tech. How odd. Definitely; one of my favorite presentations. Been watching it more than once.

[@billharris6886]

Nice job Paul! You even measured the beta of the thermistor to make sure you got a reasonably close replacement - very good! (Things you have to do when you don't have a parts list or schematic). Nice job on improvising, coming up with the circuit and PC board to allow common fans to be adapted. I suspect the designer used a PWM specific fan so he could get around having to use a fan with a tachometer output. (I hate designing circuits with non standard parts). Just a few suggestions: If you use an adhesive (epoxy or RTV) to hold a glass bodied part to a PC board, it will crack the case at some point due to the thermal coefficient of expansion mismatch between the glass and adhesive. I recommend instead to use something that holds light mechanical pressure of the thermistor against the case of the part you are trying to measure temperature on (such as lead tension or a clamping bracket). Then use thermal compound between to two parts to ensure heat transfer. With the corrosion noted on some of the parts and conformal coating used on the boards in the inverter, I would dip your fan adapter board in conformal coating as a final step. Otherwise, great job!

[@kwilde1131]

I think this is one of your top 2 videos. The other being the adventure with the Kurig. It takes a lot of smarts to approach modern SS electronics and improve on a consumer design.

[@theduckisok]

I watch these "At my own risk"! Learn something every time.

[@TRXLab]

Hi Paul, as always this is a great and very comprehensive video. All thumps up, it can't be done better! Like your little custom boards :-)

[@MrCarlsonsLab]

TRXBench Thanks Peter! Don't spend too much time vacationing, we need more video's!

[@TRXLab]

Mr Carlson's Lab HaHa you are here nothing can go wrong so I can go;-)hi hi

[@MrCarlsonsLab]

TRXBench LOL! You and your wife climb safely! Sounds like a nice place to vacation.

[@nadnerb978]

I worked for a company that got a couple thousand thermistors with the wrong beta value and a month later we I had droves of people calling me about their water being to hot! Engineering oversight 101! The IC was calling for heat when the actual tank temp was over 120F! It's the little things. I tested the discrete NTCs and the program was off by +40F ~10/25F. In hot water heater controls that's a hanging offense. Great vids man. Keep it up!

[@stephenmoore2754]

Another great repair. Thanks for documenting your work and for all the demonstrations. I wish all repairs were as easy as you make them appear :). Again nice work on the circuit boards. I am looking forward to more of the same.

[@MrCarlsonsLab]

Stephen Moore Thanks For the nice comment Stephen!

[@quantumleap359]

Another excellent vid. This type of demonstration reinforces my opinion that knowing how will get you employed, but knowing WHY will enable you to be the boss. I am very impressed with your range of talent. Thanks for the videos, keep 'em coming!

[@MrCarlsonsLab]

Quantum Leap Thanks for the nice comment!

[@dstevens7614]

Very well done. I have the 24 volt 4k model ms. I use it in my rv. I found 5 of the blue wafer capacitors broken off at the board and floating around the case. One spare was there too, it had scratch marks from sliding. I guess it was a spare part from the factory 😳. I put all the parts back and kept the spare one. To secure the caps I used a hot glue gun to attach a thin plastic line to the top and to the board. The line was for weed eaters and the very thin line. No smoke so far. Thanks for all you do for ALL of us….

[@billrussell7672]

your lectures kill my A.D.D. but I cannot get enough ,,,,,mechanic,welder gas turbines millwright

[@ReflectingMe2024]

Fascinating. Simply darned fascinating. Your presentation style is pure class, it really is. i am absolutely loving your channel. Greetings from John, MW6WHL, here in South Wales.

[@ibidapoilawole7120]

Very detailed procedure of repairing the Magnasine unit.

[@lb09486]

Great video learnt a lot. I have a MS1012 that displays OVERCURRENT after a few seconds of turning on. Can you guide me how to attempt to troubleshoot? Want to determine which broad is faulty and how to fix. Thanks a lot watched two of your videos.

[@SuperCarver2011]

Very interesting tutorial on NTC thermistors and how they are applied to this unit which has some smart engineering to protect the power FETs from over temp due to to much thermal dissipation. I don't work on inverter power supplies anymore, but I enjoyed your troubleshooting explanations. This unit is inverter/charger can generate 2000VA at at max DC input 266ADC at 85% efficiency. At 120 volt AC output thats about 16.6 amps. Fans can run from 0 to 120cfm. 100ADC max in charger mode. Besides the over temp protection, it also has over current protection. It certainly is a neatly designed unit to produce pure AC sine wave.

[@Wtfinc]

i cant beleive the thermal pad thing went unnoticed and uncorrected. 4 thermal pad were misidentified as isolation and mechanical hold downs. the whole point of having the bracket across the fets is for heatsinking.

[@orange70383]

Just a whole nother level of diagnostic repair, outstanding.

[@MrCarlsonsLab]

Thanks orange!

[@TheFunkman]

24 of you didn't like this?? Huh? Another great video Paul.

[@ovalwingnut]

GR8T Stuff. You have done a super job with your explanations, theory, background descriptions, camera work, close ups and lightning, p.s. Bonus points for no-background-music and a "feature length" run-time :O) Not to mention the post production time, to pull it all together. Thank you Mr.C. ...Favorite Line: "They must have built the entire circuit around these fans" Cheers!

[@MrCarlsonsLab]

+OvalWingNut Thanks for the kind comment.

[@dalemettee1147]

Paul, I like the fact you say, "Well, not quite the same". I have the exact problem when getting parts for my computer or my car. The computer is custom built and the car has custom addons.

[@Johne443]

Paul, you have made me a subscriber and a big fan with this video. You took the time to video the entire project with specific details on how to. As an extremely basic electronics hack. You make me look good. Thank you

[@MrCarlsonsLab]

Welcome aboard!

[@sparkitautomotive]

Great stuff, really enjoyed this as usual. It looks like you have a tiny work space in among all the test gear.

[@DosMakis]

Great and more the detailed description and proper analysis of the a magnum inverter /charger 10/10 thumbs up :)

[@mpex2006km]

Nice Video. You're videos are of excellent quality. Keep up the good work. And the answer to your question is : Thermal bonding. The darlington pair's gain depends on temperature so by making these transistors track each others temp (and mainly the smd transistor follows the series pass power transistor) you can better stabilize the darlington pair. Thank you very much for the nice content.

[@MrCarlsonsLab]

Electronics And Dsp Blog You nailed it! Thermal tracking. Thanks for the nice comment!

[@jerrymont2595]

Excellent video Mr. Carlson. Once sgain, as always, I've learned something. Keep up the excellent work.

[@robertselectronichobbies9507]

Excellent video! It is always a challenge to work on these things without a schematic so your videos are a valuable resource. I have a lot of experience with these units. If you have one that is more than a few years old you should open it up and check that both fans are running. If one is bad then it is time to replace both. If you can't fix it yourself check the Magnum website for a service center. One problem with these units is the fans do not stay on until the unit is cool after the inverter or charger is shut down. This causes moisture to condense on the circuit boards and eventually eat through the conformal coating. I think they may have fixed this on newer units. So maybe a future video could fix this?

[@llsdigitek]

Very Thorough Paul and liked the thermester beta determination and the fan circuit you designed.. VERY GOOD!!!

[@MrCarlsonsLab]

Thanks!

[@mlee3273]

FET thermistors in Parallel. You mention it several times in the video. The system will do the *same* thing if either FET bank has an over-temperature error, so - from a system design point of view - I don’t need to know which FET bank has the problem, just that one of them does. If I needed to know which FET bank had the error, I need another bit of information (literally), so I’d need another PCB track, another connector pin position, another wire in the ribbon cable and another input pin on the sensing processor. So, lots of production money saved by this clever piece of optimisation in the design. Would like to know more about how the FETs switch the inverting transformer input current, but that’s for another day. Enjoying every video of yours that I watch, and learning loads ... aged 63! Matt

[@vicosee4439]

I did not understand 98% of everything you said not cuz you didn't know what you were talking about but that I don't know so its a me issue but you talk with so much confidence that I had to hear the whole video

[@OctavMandru]

Wow man, I keep wondering how meticulous you are. Great job, great educational job right there

[@keldsor]

Wav, you are a very skilled engineer AND teacher !

[@MrCarlsonsLab]

Thanks Keld!

[@dave6501]

thank-you Mr. Carlson. Once again a great video and a cool obstacle over come. thanks again. :)

[@laser-on-off]

Hi, your PCB is awesome. Everything is so clean. It would deserve a video (IMHO), to see you making one of these with your tools/equipment. If not already done on video. Anyway, thanks for that awesome video. Again.

[@MrCarlsonsLab]

I have a few video's with board building in them, just browse my "videos" list

[@laser-on-off]

Thank you, I just found it and will watch it. :)

[@bluefishactcl1464]

Thank you You saved me lots of work figuring my AIMS inverter temperature fault ! By the way, this unit looks almost identical to the aims 6kw inverter

[@stuartthegrant]

I enjoyed this Vidio very much, I loved the way your modification enabled the Fan speed to be predicted with such accuracy. I am eagerly awaiting your next project.

[@MrCarlsonsLab]

Stuart Grant Thanks Stuart! Working on it now :^0

[@gregorywest2029]

nice video, neat circuit for the fans. Keep em comming , Greg

[@MrCarlsonsLab]

+Gregory West Thanks Greg!

[@ActivateMission2ThisTimeline]

I would have replaced with the stock fans as if you were charging by the hour the customer would have freaked out. With that said your mods and detail are incredible. The company should use better fans as they always fail first and use your circuit to use sealed ones. Thanks!!!

[@gamlemann53]

Fantastic skills Mr.Carlson! Love Your videos!

[@CRITRON]

Hey Paul. I have noticed the air flow sense was changed. New fans blow from trafo to final stage. Original sense was from board to transformer. It was done on purpose or just a distraction. BIG thumbs up for all your videos!

[@martinborman4195]

The BC-817 transistor will thermally track the 2N6121, giving thermal stability.

[@frankkoslowski6917]

www.electronicshub.org/darlington-transistor/#Why_We_UseDarlington_Transistor

[@dhadumia]

Man. That was quite depth actually!! I am mechanical engineer and totally novice into this sector and that's quite deep for me. 😳 But I am wondering who are the 37 people who disliked this video?

[@christopherthumm7861]

U R a rockstar in my world!!! i have a cathode-ray oscillograph i use in my studio , i enjoy all your shows keep up the good work

[@davelister796]

LOL, Don't sugar-coat it, tell us what you really think about those Bisonic fans :-) Love your videos. I didn't think I'd be interested in this video, but brilliant information about thermistors, fans, PWMs, and troubleshooting in general.

[@MrCarlsonsLab]

+Robert Speckmann Thanks for your kind words Robert!

[@lesjohnson9740]

I will have to watch this presentation again a few times, to get my tired old brain in gear, as always Mr. C.

[@MrCarlsonsLab]

+Les Johnson Glad your enjoying the video's!

[@kendoty2463]

Once the variable resistor is set it is a good idea to measure it and replace it with the next lower value in a fixed resistor, considering salty environment. Thanks for great video!

[@shmehfleh3115]

Things have changed a lot in the past few years. Most PC fans available these days are PWM-controlled.

[@tomrandall4871]

Excellent video on Application Engineering!

[@GoldSrc_]

Is always great to watch your videos, whether it is just to sit back, relax and watch them or keep them playing in the background while I do some soldering. Keep up the good work sir.

[@MrCarlsonsLab]

Gordon Freeman Thanks for the nice comment Gordon!

[@AW-Services]

I totally share your views. Last night i had a video playing in the background while doing some work around the house. Very calming to hear Paul and the high level of his knowledge and expertise is amazing. A big hello from the UK 🇬🇧

[@bucyruserie1211]

I don't know much about transistors and I am most likely wrong, but maybe you mounted it on the bottom so if it gives off heat it will transfer to the heat sink and radiate off? The more video's of yours I watch, the less intelligent I feel! Really quite amazing the knowledge you have and how you apply it to creatively repairing equipment...even designing them better then new. Just incredible.. I think the few people who leave your video's a thumbs down are jealous. Take care, Tom

[@MrCarlsonsLab]

+Bucyrus Erie12 Thanks for your kind words Tom! Good try, but more for stability. I have answered this a few times in detail, just scroll through the comments.

[@AntiqueRadioandTV]

Only you Paul, could make an interesting power inverter video! LOL You turned something mundane into something quite interesting. It sure brought me back to the days in the 70's when I was bench repairing AC supplies to drive million voltage doubler stacks for Ion Implanter machines. Thanks for the beta analysis on thermistors. I now, because of your clear description, understand their non-linear resistance behavior at varying temperatures. I realize now I know how important it was to choose the exact replacement thermistor when I was troubleshooting my kitchen refrigerator cooling problem. Choosing the wrong one might have given way off swings of refrigeration temperatures which were being monitored and controlled by the cpu. Also, nice remedy to the PWM output to the standard CPU cooling fans. Love how you make these PCB's on the fly like that! Sure still wish some day you would show us that process from beginning to end and what equipment you need to implement in making them. Another great video my friend, Thanks and 73s Tom

[@MrCarlsonsLab]

***** Thanks for the kind words Tom! I really have to get to that PC Board video. Million Volt doubler stacks! Wouldn't want to be zapped by that!

[@AntiqueRadioandTV]

Mr Carlson's Lab Yeah... fun stuff. After the repair of the supply we would test it in a two story Faraday cage that housed a two story voltage doubler array. I would stand outside the cage, (Duh... of course), and monitor the ramping up of the stack. You would feel and see the hair on your arms standing up as the voltage increases. This is the really, really fun part. If a breakdown did occur, there would then be a four to six foot length lightning bolt discharge to ground. All 100+ plus people in the factory would jump as the "clap" was so loud! Great times.

[@MrCarlsonsLab]

***** LOL! High Voltage is FUN! Do you remember what kind of stack it was?

[@AntiqueRadioandTV]

Mr Carlson's Lab Oooh... It was sooo long ago. I kind of remember what it looked liked, that's all. I couldn't give you a name of the deign that was attachéd to it. A man-sized aluminum box with rounded edges with hollow aluminum rings stacked above it with HV caps between the rings. It was about two stories tall all together if I remember right. I didn't work with the stacks directly. I just used them in the cage to test the supplies that I was repairing. As a side note: You know how you warn us about the dangers of working with voltages? I knew a guy on the assembling line who got killed because he had his wedding ring on. Jewelry and voltages/currents are a real "no-no!"

[@MrCarlsonsLab]

***** I know some bad accidents from jewelry as well! I had my time with a watch band. OUCH!

[@Tony-xq4iu]

Excellent video. Good to refire neurons! Youre are very thorought! Excellent work, great video, and very much appreciated

[@MrCarlsonsLab]

Thank you kindly!

[@rib180]

Gain of a darlington pair varies greatly with temperature. Perhaps the MCU PWM control is to prevent undue thermal cycling. I cringe when I see someone resting their fingers on components when pointing, especially on metal terminals. In a past life I used to test and repair a 50KW three phase UPS run off of 240v batteries - the magnetics were so strong that sparks jumped across the open cabinet doors. Thank you for your informative videos. The devices that you work on are beyond my price range and nice to see the insides and how they work.

[@absurdengineering]

That was piss poor design then. I deal with 3-5kW high frequency inverters and you don’t want any magnetic leakage since it radiates like crazy and makes it impossible to remain electromagnetically compatible with anything else (most importantly - the law). Having enough leakage from the magnetic circuit to produce large enough current via enclosure metal that it sparks is absolutely unconcscionable, assuming that the device was operating as designed (ie had no fault not wasn’t field-modified aka broken by the clueless). I have worked on 50kW servo drives and there was no problem putting iron loops around them. It’s the normal mains transformers that were problematic, but those work at 60Hz and weren’t part of the inverter itself. Their excessive magnetic leakage was due to marginal transformer design - the inverter wasn’t to blame for it. The inverters I work on have 1MHz commutation frequency. Their magnetic circuit is relatively minuscule. The magnetics for a 5kW version fit in your palm! The 50kW version has them only slightly bigger and there are 3 modules running in parallel - still extremely small for a device that provides full galvanic isolation and pushes just shy of 20kW of power across the barrier.

[@anthonyudekwu6615]

Great diagnostics and innovative improvising .

[@kg2nc]

Another great video Mr Carlson I really enjoy it.

[@MrCarlsonsLab]

Ruben Thanks Ruben!

[@stazeII]

transistor location on the back side: it's because beta/gain is temp dependent. So you're trying to make sure they stay relatively the same so they "scale" in beta as they warm/cool down. It's why they make packages that have complimentary pairs in them for amplifiers... so they're nice and thermally coupled. =) Great video, as usual, btw.

[@MrCarlsonsLab]

stazeII You betcha! I'm really going to have to "up my game" with you guys :^) Thanks for the nice comment!

[@stazeII]

Mr Carlson's Lab Eh, it's covered pretty repeatedly in Art of Electronics, and another book I own that talk about amplifiers... so no fault of yours that it sticks out in the head. Now, ask me to calculate quiescent current and I'd be hitting the books. =)

[@calescapee9642]

Good video. I need to repair/replace the fans in my inverter. Cool Lab also.

[@MrCarlsonsLab]

Thanks!

[@ChrisOrtizSirCable]

Always great information my friend !! Keep up the great work..

[@MrCarlsonsLab]

Chris Ortiz Thanks for the kind words Chris!

[@timwalling3101]

thanks Mr Carlson for all your excellent informational knowledge and superb videos...I was noticing your name on all your boards you make and think it would be cool if the"S" in Carlson was a stylized lightning bolt in the shape of an S just thinking like the graphic designer that I am....thanks again for the inspiration in excellence.

[@supyrow]

my guess on your trivia question, thermal balancing (even though you said the temp of the to-220 doesnt get warm, im still guessing thats it.) Love your videos!

[@MrCarlsonsLab]

su pyrow You got it! Thanks for your comment!

[@materialsguy2002]

The original fan looked like a sleeve bushing vs (most likely) the VAPO/Maglev bearing system for the Sunon. According to the literature the Sunon is sealed, so you should not have to worry about the fans again. I enjoyed the video, thanks.

[@MrCarlsonsLab]

Shaun Merrigan Thanks for your comment Shaun! They looked like good fans, I hope they last for a while.

[@drubradley8821]

Yet, another great video!

[@MrCarlsonsLab]

Thanks!

[@prezillogic9230]

amazing best teacher ever

[@TheRangerDale]

Very good Paul like always., Saw that I miss this one few months back, So like when you was a Kid and a Long Ranger Show was on TV , yep was Glued to it .Nice info, as a retired Full time RV'er know a lot of Hams that are Rv'ers I passed this one on lol .. 73's Paul

[@MrCarlsonsLab]

Thanks Dale!

[@MaxKoschuh]

I didn't expect to watch the full video. But I did, it was very interesting. Max, Austria.

[@MrCarlsonsLab]

Max Koschuh Glad you enjoyed Max!

[@layeraddict]

Man ,you are very good with electronics.I really liked the pcb , great job !

[@MrCarlsonsLab]

+NoCoke Thanks!

[@davidlisney2059]

An excellent video as always, regarding the small transistor on your board I wonder if you are trying to get a little thermal feedback so that as the power transistor warms the VBE of the driver will drop a little pushing the power transistor further into conduction. Well done on doing a thorough and proper repair. I did wonder whether you could have cleaned up the PWM pulses with an RC network but your solution is very professional and a credit to you.

[@robertdoell4321]

Again Great Job Teaching.

[@matthewprestine1974]

another great video, thanks for taking the time to share.

[@MrCarlsonsLab]

Matthew Prestine Glad you enjoyed Matthew.

[@johnjacob757]

We have several of these units. Now I understand them better.

[@user-zw9rq7rw6s]

Very cool thank you for this it will hopefully help me with the issues i got on my boat. The think might have been submesued in salt water had some rough weater for the crossing from St Thomas to Panama

[@jamesgrimm611]

Great repair learned a lot.

[@TraderRoss]

great video to enjoy with the morning coffee. I will check out some other vids.

[@MrCarlsonsLab]

+Warsrogue Thanks! Glad your enjoying!

[@PapasDino]

Nice tutorial Paul, thanks. Look forward to seeing your PCB making video. 73 - Dino KL0S

[@MrCarlsonsLab]

Dino Papas Thanks Dino!

[@johncramer99]

Love the vids. Learning alot. Just cant stop thinking about MR Monk though.

[@oscarwylder]

Absolute genius - Thank you.

[@gacherumburu9958]

Thanks for the info! 👍 Great video!