Interesting fault and fix on a Dixell XW70K refrigeration controller
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- เผยแพร่เมื่อ 6 ก.ค. 2023
- This started as a very ordinary fault with an easy fix, but then I discovered that a section of the circuitry was getting extremely hot and had to explore further. It turns out that a classic fault was causing a weird knock-on effect that was so unusual that I felt the need to reverse engineer that section to see why it was happening.
The main culprit was a classic bulging capacitor, but it's much less common to find that fault in equipment with traditional low frequency power supplies. It's much more common with modern high frequency supplies. The use of the Glan branded capacitor may be the issue here. The circuitry shouldn't really be stressing it with a guesstimated current demand of around 300mA with active relays.
The unit has the facility to connect a remote display and button interface with just two wires, and it appears to achieve that by using a current regulated supply to that module, and communicating in both directions by shunting its power wires in pulses.
The main capacitor failure caused an unexpected situation where the processor was unable to initialise, and by default the display output data shunt is active, meaning that the current regulation circuit was dissipating high power in its main transistor continuously.
As the capacitor progressively failed the unit would potentially have started glitching and resetting intermittently, getting progressively worse until it just didn't start up.
One huge advantage of doing an on-site repair on these units would be that it keeps their existing settings intact, which saves reprogramming the unit for a specific system from scratch. That can be a real time saver if you have to work out what everything is doing and how it's connected.
Without a working reference unit for voltage measurements, and perhaps a remote display module too, it's hard to say if other damage has occurred. But the configuration of the circuitry and now cool transistor suggests that the fault is fixed and these units have been saved from becoming expensive landfill.
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#ElectronicsCreators - วิทยาศาสตร์และเทคโนโลยี
I wonder if it is always "planned obsolescence" or if some companies just underestimate or do not test for longevity properly. I just fixed a friends's portable induction stove - The fault was a 22 Ohm resitor (roughly rated for 2-3W, from what I could see), that had gotten slightly too hot over time and slowly crumbled until the resistance wire broke and the stove would not turn on anymore. No skidmark or any sign of an explovie fault, just crumbled! I replaced it with a resistor of slightly higher power rating (and did the same on the other plate, that had identical circuitry, but had not degraded yet because it had not been used as much) and now it works fine again. 1€ fix to save it from the landfill.
I hate to think how many products end up in landfill because of a simple resistor or capacitor.
Also could be because engineers with less experience are cheaper to hire. Somebody I know who only recently graduated got hired to write control software for car clusters... the thought is slightly terrifying.
Did vaguely similar things to a NEFF (Bosh Siemens) branded, made by E.G.O one. Each phase has a power board, on those the high frequency fets/IGBTs short, burn out the bridge rectifier (maybe the rectifier dies first, not sure). Then melting a pcb fuse (which ironically has provisions for replacement hrc fuses lol). Happened twice to the same stove on different power boards. Granted the thing is over 10 years old and is powered 24/7, maybe it was due to power glitches.
Thats a sub 30€ fix on that one. New fets and a bridge rectifier.
A lot of times its simply over stating capabilities. Sure this, say fridge (that has nothing to do with Technology Connections latest video.....he lied), could keep its interior at a lower than ambient temp. But the parts selected arent necessarily meant to keep the entire volume, full of groceries, below the danger zone. What is it actually meant for? No idea. Maybe its meant for an arctic research base where it wouldn't have to run very often, no clue.... Of course there is always the accountants that love to stick their noses into designs. This is where you get things, say with a motor that pulls 2.4A and a FET running it that tops out at 3A. Because its cheaper than a 5A FET that would last forever. Of course its going to burn out if you use it like a normal person, repeatedly, beyond its 'no more than 10min. 90% duty cycle cool down' rating. But its printed in the instructions, so..... user error. Buy a new one.....
It has a microcontroller, it would be so easy to program it to stop function after so many thousand cycles rather than say to a company please make us awful capacitors and jeprodise your reputation
The toothpick technique is so simple yet so genius! Gotta add those to my kit now 😅
I actually bought a full set of soldering needles for £2. They’re absolutely fantastic for mosfets packages and all sorts. They are hollow steel tubes which perfectly isolate the solder around a component to remove it without the need for any desoldering braid.
Takes a little time to master but is now my go to method!
Its so nice to be able to repair our own things. It saves money and saves waste. 😀👍
I still remember that slew of electrolytic cap failures on motherboards and electronics in the early 2000's which resulted in the shift to solid caps for motherboards. But if you look closely, some of these caps still use liquid electrolytes but with form factors resembling solid caps.
That was due to a Chinese company stealing an incomplete version of Nippon Chemicons capacitor formulation, then sharing it around. It lead to a large increase of ostensibly high quality capacitors at cheap prices, but they died pretty quick, leading to the cap plague of the 2000s
@@SkigBiggler - It was worse than that. United Chemi-Con had a huge range of caps that went bad (KZB/KZG) so entire runs of Intel, Dell, etc, motherboards with known good brand parts went bad. (Pentium 4 boards, mostly. I have three in storage waiting for recapping to be stored for replacements. Old control computers that can't run on anything newer than P4)
I started my electronics career repairing refrigeration PCB's. I can tell you capacitor failure on this type of power supply is super common, not sure why but I've repaired literally hundreds. Great throwback 👍
Dixell is an Emerson brand, and Emerson makes quality stuff. Glan's web site looks quite professional and says they "have offered OEM & ODM service for many famous brands". In other words, they have manufactured capacitors sold under other perhaps more recognizable brand names. So it could have been one of those relatively rare unavoidable failures. Also, in recent times, many components, including electrolytics, have been in short supply. I struggled to find a high quality alternative for a 220uF capacitor in one of my own designs and actually had to switch from a surface-mount part to a through-hole one for one production run. Perhaps Dixell had to do the same and were less successful. In any case, I enjoyed, as always, Clive's masterful reverse engineering and nicely done repair. And I just added a box of round toothpicks to my collection of soldering supplies.
The unit looks quite well designed. I think it's just an unfortunate choice of capacitor with an electrolyte issue.
There's a decent chance this controller was installed in a rather hot location. Refrigeration equipment controllers can end up installed inside a cabinet within the enclosure of rooftop equipment, and depending on the design it may not have good ventilation. Could well have been baked.
Or the other extreme; if it was installed in a low temp freezer by somebody who didn't realize the controller can't be installed on the evaporator in a very cold room for long term use.
Would this be the same Emerson that also makes shop and commercial cleaning equipment? (Ridgid and ProTeam) Oh, sorry, I guess it does as I see Dixell is a Copeland brand owned by Emerson.
Big name brands often use terrible capacitors because it saves them way more money than it would save a small brand. (Quantity) So the fact that they claim to sell to to many big names probably proves that they are junk.
And having a nice website was more convincing back when someone actually had to type clunky html code by hand, not drag and drop things in web design software.
The smaller dixell controllers are notorious for catching fire. I bin them the minute they show any sign of case deformation and replace them with Carel brand
I've made so much money in my career from faulty electrolytics. God bless them. I remember when mini camcorders first came out. I was living in South Africa at the time and it seemed that no engineers in the area wanted to touch the new microelectronics used in these camcorders. If you remember they used aluminium radial electrolytics that were well known (to me anyway, in SA) to leak and go faulty in a few ways. Lets just say it was a great career and economic advantage for me to be aware of this and to be prepared to tackle faults in these tiny circuits. Love your videos btw Clive. Thanks for making them.
Really enjoy the repair videos, you should do more. Might not her the clicks from passing viewers but I'm sure long time followers would lap it up.
Fixing stuff and modifying stuff to work on solar panels. Suitable panel and diode yeah but
I'm sure you have thought about something that seems obvious to you but not to learners. Every good engineer starts with a good mentor 👍🏻
Something I like to do when replacing an electrolytic capacitor, after noting the negative side as you indicated, is to look at the circuit board where the capacitor goes. Most of the time they will have silk screening that indicates the way the capacitor is supposed to go. I like to verify the polarity of the capacitor with the silk screening because I have a tendency to forget things like which way a stripe was facing two seconds after I made note of it.
It's just not a proper Big Clive video without the bulging Glans.
& "todays special guest on this Big Clive episode Richard Senormous who will present a lesson on loss of current due to wire girth & length.
It's an expectation nowadays. LOL 🤣
Good on you for doing a bit of solid simple education. Be it the mechanics of pulling it apart or the basics of recapping, there’s a lot to apply generally to fault finding
Excellent repair and soldering primer! I've done that for more than fifty years, but I always enjoy your presentation.
Finally just finishing up restoration of my 1982 Fruit Machine (Jpm eachway shuffle)
Had to replace a few caps, but there are still plenty of them left still working after 41 years!
Same story with most of the TTL, I had to replace some due to corrosion on the legs, but still plenty of chips left working, some with date codes from the late 1970s. Just goes to show how well manufactured components can last for many many years.
(Counters in the bottom show in excess of 11 million plays while it was in a busy arcade😮)
I had some scrapped Ubix copiers I bought on auction for lower than scrap metal price, and most of them had 6 digit mechanical page counters in them, the one with an 8 digit counter was well over the 80 million page count. I repurposed one of those counters, after opening it to reset to zero, as a cycle counter for another machine, and when that eventually was sold on it had also rolled over twice on the 6 digit display, and was still running well.
I estimated that, based on the previous owner use, the machine had probably done over 200 million cycles before it was replaced with a new one, after around 20 years of operation, as it ran 24/7 in the previous application, but with us it ran perhaps 6 hours a day 3 days a week, at a much slower rate. Original German manufacturer still had some spares for it, but mostly it was a good machine shop, and fix what was broken, instead.
Does the counter still work? Sometimes they clock up such high plays that the counter rolls over or just twitches the last digit without incrementing.
I have seen hollow "pins" of different sizes sold on amazon to do what the tooth pick does for a lot more then the tooth picks costs. I would never have thought of that on my own . thank you thank you thank you!
The hollow stainless pins are good for desoldering some components with a lot of leads.
What a nice change from the usual tear down videos. I like seeing the hands on videos where the soldering iron comes out.👍
I have an industrial aircon friend here in Australia swears by dixell controllers. He claims the only thing the don't do is swallow. I have used an few of the simpler panel mount ones and found them to be easy to use and totally reliable.
Looks like it was suffering from swollen glans... painful. Love the tooth-pick tip. Soldering for 40+ years and never heard of it. Can't wait to try it out.
I've found those pen-based flux dispensers very handy - cheaper, refillable, and it doesn't waste flux. A single press on a joint does the job.
I got a pack of dropper bottles, and used those instead, as they are also easy to refill, and the pack of 20 was cheaper than a single flux pen, plus if you have one leak it is easy to replace, plus you can keep a few around so no need to refill immediately.
You should send one to Louis Rossmann as a gag gift.
@@chrimony Absolutely. This pen dispenses flux in microRossmanns.
When I worked in production we never had those, know nothing supervisors and managers cracking the whip but not supplying the tools and consumables to do the job properly, the company died eventually of course.
We had a qualified certified experienced EE, he designed a SMPS for a USN system, he used a single sided PCB, then took a couple of the units from the first batch to the RN shock tester platform at Portsmouth, all the heavy components fell off the PCB at some high G shock. We had to scrap 50 or so populated PCBs after removing the transformers connectors and expensive components, the Rs and small Cs were thrown away with the useless PCBs. the 90s.
The 18 gauge hook up wire inside a refrigerator sized star delta transformer unit, the wiring smoked then caught fire when tested. Quite funny to hear about on Monday morning.
Excellent video. I enjoy watching you solve and fix a problem
A big piece blob of Blue Tack is really helpful in holding components to the board or whole small boards to the table when soldering.
Especially if you have shaky hands that you can rest on the table as well.
Thanks Clive. By far my favorite electronics show!❤️
Thanks for another great video Clive 👍
I'm 100% stealing that toothpick tip tip, that's incredibly useful for when those thru-holes refuse to open up even with a wick.
Some good olde schmoke prevention. Great video as always, thank you Clive!
Great work, thanks Clive.
In 1972, while testing a power supply unit I designed in the University laboratory, I noticed one of the transistors in the unit was very hot. I desoldered the transistor and tested it with an oscilloscope transistor tracer. For a whole half an hour the beautiful graph of collector-to-emitter current vs collector-to-emitter voltage at a dozen various base-to-emitter (B-E) currents was stable and slightly varying as I tested the transistor to increasing maximum B-E current, first at one milliamp and ten milliamp dial notches, then 100 milliamps intervals, and, when reaching 2 amps of B-E current, the curves wobbled, the transistor released a wisp of smoke, and the curves went flat to zero current. I was amazed. Two amps B-E current to kill a transistor? Of course, it was not constant but maximum, the tracer ramping it up in the various curves, only the upper one correspinding to 2A, but still.
I once had a TO-18 transistor vaporize two legs and melt the paxoline on a PP3 powered RF circuit. very strange.
Clive have you ever had an apprentice? I reckon (if you had the time and inclination) you’d be awesome at hosting a second channel where you share those all important tidbits a mentor shares with their apprentice with videos like this. They need not all be full length masterpieces like this. Wether you’ve had an official apprentice you’ve doubtless inspired many aspiring technical people.
Interesting explanation and repair.
The remote display communications technique reminds me of the way RFID systems work... Great video Clive...
Love the toothpick idea. Great demonstration. Thanks.
Nice work Clive as always 🍻👍🏼💡
PTC is there also to reduce inrush, as those small 3VA transformers are almost always internally protected, both by the inductance of the primary winding, and by a built in one time thermal fuse as well, buried in the potting.
With the capacitor I would go to a 35V one, as the 25V ones on 18V are being run rather close to the limits, and the 35V ones tend to also have better ripple current capacity, which here equates to a longer life, and likely comes in the same can.
I would also go with a 105C rated one, as opposed to an exact replacement for the original...
@@Roy_Tellason 85C vs 105C the make and series is more important, you get plenty of different ones, with life varying from 1k hours to 15k hours for the same capacitance and voltage, just different makes and series. Derate the voltage and life is a lot longer.
Thanks for the Toothpick trick, I had no idea!
Just like grandma used to say..."If you poop too fast you might get splashed!"
That powerline communication is so clever. Would never have thought of something like that
The same principle is used by the "1-wire" bus by Dallas semiconductors, now owned by one of the chip giants . But 1-wire ran at 5V, not 15V like this display interface .
These controllers usually sits on the top of industrial fridge and freezers, where the compressor and condenser also is and it gets hot up there in the summer.
Well discovered. Always a challenge in design to cater for any eventuality, especially in power supply designs, but, yes, use quality components. Let's not forget a supply of plasters, especially if any associated lamps require servicing.
Have seen a few of these, used in supermarket cabinet refrigeration, often connected a Modbus module then connected to Emerson control panels. E2 etc, dixell is Emerson product. most of it is made well. they are easy to program
It is a well made unit. Just hobbled by a rogue capacitor brand/batch.
Genius! Thanks Clive.
Freaking amazing reverse engineering skills.
Can you do a series on your tools(toys)?
i like the tooth-pick trick. i have had issues with just this thing. although last week i bought a Japanese engineer brand solder sucker, an ss-02. and it is amazing. i had used several of the cheap blue ones that get given away in soldering kits, and i found them awful. so before spending a lot on a de-soldering gun thing i tried the engineer. some circuit boards i have found use a little metal tube thing with a crimped over end on all the cool stuff. the full wave rectifiers, voltage regulators and heat-sinks all use this arrangement, the through holes are big, and they have this tube gubbins in, it makes the solder have a pretty flower petal pattern in it. i dont know what they are called, nor what they are for, but it makes things a bugger to de-solder, but the engineer's silicone tip lets it get right against the hot solder, so now all these nice things are in little drawers on my wall, rather than on an old PCB in the bin.
i asked chatGPT what they were, it knew right away, they are called self-clinching standoffs. so now i know!
Awesome Video big clive
I notice the friemdly board designer printed a nice + where the plus lead of the capacitor goes, just in case someone didn't memorize it during the recap .
I wonder if these can also be controlled by something like an XWEB 500 like the one I did a teardown and unbricking of a while back?
Hey Clive! I just had some components go bang on one of the boards within my 6 kW solar inverter, would you be interested in making a video out of taking a look at it for me? While I can do my own soldering, I'm unfortunately just not bright enough to know what to use when the old part fails spectacularly enough that the markings on it are no longer legible.
Thanks so much for putting out videos like these! I appreciate the content so much, and I really hope that one day soon I'll be in a position to buy you a coffee, or a whiskey, or really just contribute in any meaningful way.
Stay awesome, man!
I wasn't sure if it was Glan or Gian like a Chinese capacitor or something. Huh, toothpicks for a desoldering tool. Thanks Clive, that will help the next time I am desoldering through-hole circuitry. Well, I was always taught that, "A system is only as good as its weakest link" and that's pretty much your conclusion on this, I guess? It's interesting how one capacitor can bring down an entire relatively expensive refrigeration controller like this.
great tip on the toothpick!
I like the cocktails stick trick.
Electrolytic capacitors are the Kryptonite of electronics.
An excellent repair. Very interesting communication method to display unit.
Watching this video reminds me that I have to repair my bench power supply, as it's output transistors failed in an accidental short circuit incident, while it was set to maximum voltage and current. 😢
Definitely the output transistors? A common bench power supply failure is the diode across the output going short if reverse polarity is accidentally applied to the outputs. (Like naughty battery charging.)
@@bigclivedotcom" Naughty battery charging" Ooh err missus "
On wiggling the faulty cap out....:
A few days back I came to watch the 'Desoldering Made Easy - Amazing Trick'
from Mr SolderFix right here around the next corner on yt.
I never desoldered (multiple pin) components more easily and more important without any relevant destruction observable on the component..
Always interesting to see how cheap components like that failed cap can make electronic devices fail. From what I've heard it's quite common in the entertainment electronics industry to use electrolytic caps for "planned obsolescence" purposes. Flat screen TVs seem to be especially bad, it's always funny and sad at the same time when you hear that someone fixed a TV that cost 1k€+ new and failed after maybe 3 years, and fixing it only takes a screwdriver, spudger, soldering iron and replacement caps for maybe 1-2€...
The control panel board of my washing machine is held on with similar clips and no screws. The brittle aged plastic had most of them snapping off when nudged enough to let the board out. It turned out failure of more plastic is what had me in there at all: the water shedding lever between the human's finger and the board's button was fine one day and crumbled the next.
I'll keep a few, ish, old ones from the scrap bin and send you the parts. I'll let you know ahead of time. Cheers. Good luck.
I have swapped out dozens of these boards, 99% of the time it's the relays burning out because the manufacturer decided to switch something directly off the board. They may look beefy but if you use them for anything other than switching proper relays it will burn out quickly.
Yeah, that's annoying when they use an onboard relay for a high load. Some use an offboard relay module.
And no snubber circuit across the contacts.
"It's A Glan !!" - Here's Clive, handling a bulging Glan between his fingers ..... it does look hard and bulging, for sure. 00:42
Do you have a good source for buying ust one size/ type of these soldering iron tips? Found it hard to find multi packs of the one I want.
Thanks for another great video, Clive. I appreciate the point about not using plumbing flux. I have used it for large, difficult, connections to achieve a properly soldered joint for high-current automotive connections. How would you suggest cleaning off any residue from using such a flux?
Why are you recommending leaded solder? All modern boards are lead-free and mixing solders can cause more problems. Lead-free solder is not that hard to work with, although it is different to work with in that it requires a slightly high and more tightly controlled temperature.
Also, I'm not sure you completely repaired this controller. The controller casing stated 6 VA maximum and the figures from the HOPI calculate to 8.9VA,which is nearly 50% over the maximum power rating. Maybe investigate further?
Funny enough, I just fixed a restaurant freezer with a different model controller (XR06CX). Programming these pesky little buggers is a bit troublesome, haha!
The freezer just kept turning off and not cooling - at first I thought it was a controller bug but it was okay when I measured it, then I noticed that the condenser's and compressor's cooling fan was powered but the motor was stalling. Replaced the thing and it works. The old motor, probably the filthiest thing to ever appear in my lab, is waiting in a box for dissection.
To think they used a crappy cap in that one... When I took apart the XR06CX, it was just so packed, nice jobbie for a compact unit it was, and the filter cap was probably something in lines of Nippon Chemicon... I haven't taken a closer look.
You might as well cut a piece of copper wire (1mm² or so) as a thermal bridge to heat both leads simultaneously. This does wonders for multipin components, but makes cap replacement a lot easier too. After desoldering, I usually clean the holes with a syringe needle.
Don't use thar copper trick under power, it'll be a dead short .
@@johndododoe1411 of course absolutely not! But then, who even desolders caps live?
@@KeritechElectronics Anyone trying to repair a running system too important to power off, preferably using redundant capacitors in parallel . Hard stuff, never needed to do so myself, but contingencies must be planned for .
@@johndododoe1411 I've done work on running electrical wiring, I've done module replacement work (as in, disconnect a cable, swap the out-of-board parts, reconnect) on running automation and electronic devices, but I'd find it absolutely crazy to do PCB work live. Like, so many things can get borked - and if that happens, you're in for not only putting the system out of use, but also having to order an expensive replacement and waiting till it arrives. If you're really wise, you'll have a redundant system for instant switchover when the running one fails or has to be taken down for maintenance... if you're just wise, you'll have a known good replacement in storage for a quick swap, and do the fixes on the failing one. But then, it's still a device or module level work.
@@KeritechElectronics Redundant devices with seamless switchover is definitely the reliable way to design always on systems, soldering live equipment means the system was not built that way or all the redundancy has withered away from years of tiny budgets, and now the poo hit the ventilator and heroic repair is needed to stay operational .
We use and commission a lot of dixell/Emerson products for supermarket refrigeration here in Aus. Generally really good quality from Emerson
These controllers may have come from Oz.
Use a lot of dixell unit's at work, mainly the XW60K, generally pretty reliable. Occasionally get the odd failed relay.
Think the keyboard runs on 12v and pulses low for the data.
Would you reverse engineer a FS1000A radio module, or similar one ?
I'd like to learn more about those radio modules with cristal osclillators
And i'd like to modify one, but I don't quite understand it
I repair epos motherboards all the time and always use Panasonic long life caps now. My desoldering suction gun is the best investment I ever made
did you open the cap to make sure it didn't have a smaller cap inside it?
What a coincidence, I just fixed one of these last week. The big black relays are a main point of failure.
I'd guess it may be switching a load like compressor or defrost heater directly.
I had a Radio Shack 330mf capacitor. I left it in my supplies box in its little baggie. It was fine. I never used it. A couple of years later I wanted it, pulled it out and it was bulging so badly that it was coming apart. Never ever been used!
That's quite odd to have the electrolyte degrade and gas out in storage.
Nice trick with the toothpick.
Thanks for this great instructional video.
I had a similar power supply circuit with a blown T160mA fuse soldered on the board instead of a thermistor. What could be a suitable thermistor value as a replacement for this fuse?
Very good that you stressed to look at the polarisation of the electric cap, it is often printed on the board as well but I've seen that the polarity is not always correct and so you cant rely on it.
It would be much easier to replace your PCB fuse with another, since they should rarely fail unless there has been a short circuit or overvoltage incident. You could use a standard 20mm fuse with wires carefully soldered on.
PTC aren't always the best solution. They don't completely break the circuit as does a normal fuse. They also have a region of what essentially amounts to unpredictable behavior.
If there's a fuse there already I would just replace with another fuse for safety's sake. You could look into installing a fuse socket to make replacement easier.
It's always CAPS CAPS CAPS that seem to be an issue with high powered devices, sometimes it's better to not cheap out on most important part where you are temp storing energy.
Very intreresting design having the live and neutral on separate terminal blocks, why would they do that over having them on the same one which seems logistically easier.
It is odd. I wondered if they just wanted to limit the number of ways of the connector and that was just how the connections landed, or if it was to prevent damage if the connectors got swapped.
Did you have two fault glen caps? One had short legs and the other had uncut?
I tacked on extra leads to test the faulty capacitor.
This is strange. Why the 15-18VDC supply? What is the relays coils rating? Also I would not use 25V cap on this supply....rather double the cap voltage rating....they will last longer.
Exploding electrolytics! Can remember having a couple of nee - well ok new to us, system boards as trials. Neither powered up but hmm smelled a lot. Me being me took them apart. All looked clean except the mains area. The smoothing capacitor in both units had exploded. More like a volcano. Took a while to workout that the capacitor in both units was put in reversed. Replaced and all was ok check with company and hmm manufacturer fault. The entire batch were built the same.
Question. Can putting tin foil at the end of a treble A battery be unsafe in any way in overheating, fire , e.t.c . Inside an AA powered clock? Edit this is near a gas pipe, but literally Nowhere long enough to cause short circuit just enough to hold the battery in place, Like in my head it looks dodge AF but my brain is saying it's just going to drain the battery faster and worse case scenario the single piece of foil followed by the battery will just fall out. As a temp hack is it horrendous?
I wouldn't recommend aluminium foil, but it's not uncommon to use a small stack of steel nuts and washers to fill the gap.
Do you happen to know what those green connectors are called? I've run across them in a few places, and they strike me as being pretty darn reliable...
Phoenix connectors may find them.
That 'on and off' communication sounds a LOT like the old Telephone rotary dial scheme with toggling the hook/cradle. I would bet that it would be a fairly simple protocol to 'sniff' with some current shunts and/or measuring probes. I wonder if it is like some of the "AC" units where the remote display actually sends the ENTIRE CONFIG every single time you push the button.
A lot of micros default to "input, pull up", that would turn that transistor on.
@13:13 toothpick - very good tip! pun intended. :)
We had some failed capacitors with VENT brand in a number of network equipment. A brand with a promise, so we named them Will Vent's capacitors.
Hi, what's the name of those green connectors at the top of the board?
I tend to call them phoenix connectors.
"PCB mount screw terminal block connector"
There may be another name, but a search for that should turn up what you're looking for.
Do you need to discharge the capacitor before removal?
Well, in this instance, no. The cap is faulty, and won't hold a charge. That's the reason for the overlarge ripple voltage which caused the transistor to overheat. Secondly, the voltage across the cap would be 25 volts or less, which is not a dangerous voltage. In the case of higher voltages, it would be wise to use a voltmeter to check for any stored voltage across any capacitor you intend to replace.
No. It's low voltage and will discharge through the circuitry for whatever capacity it has left
I have a Mobile Phone charger that is 5V 1000Mah. Is there an easy way to limit it to 4.5V externally?
If using it to power something that runs on 4.5V it's usually enough to put a standard 1A diode in series.
@@bigclivedotcomYep, that's the way. I adapt a lot of my old 5V psu's/chargers to run equipment that use triple 1.5V cells (4.5V).
I think that would fall into the category of "Spoiling the ship for a ha'peth o' tar"!
But still, it keeps the workmen in a job!
morning Clive. Would you be able to help with a treasure Hunt puggy that stopped working. 80's machine just buzzes.
First suspect is the power supply capacitors as in this unit. The lack of smoothing may manifest as audio hum and the processor not booting.
Hi Clive. A question… Are you aware that TH-cam is now putting mid video advertisements in for your videos?
Yes. It's a test to see if they were muting my content due to the lack of advertising revenue.
Glitching the power supply... very naughty communication protocol.
Toolkit called "Hollow needles desoldering tool electronic components Stainless steel 8Pcs/lot" for $2 may be very suitable for desoldering various through-hole parts. Sometimes I prefer use toolkit for $2 instead of Japanese desoldering gun for $200.
Someone at work connected an electrolytic the wrong way round it did make a loud pop and the room was filled with snow
A lot of companies will just swap the controller out for a new one, which creates more sales for Dixcell, so the cheap component might have been deliberate. But of course it will give them a reputation for poor reliability and in the long term will damage business. But companies don't think long term.
I misread the title as 'weird and insulting fruit' - probably not beyond the scope of a Clive video :p
Or maybe that's just how you subconsciously think of Clive 😂.
5:49 I _think_ polarized capacitors _should_ be inserted with their negative pin at position 1.
You suggested that a faster switching frequency puts more strain on a capacitor. I would imagine a faster switching frequency would reduce the ripple voltage, but the average current through the capacitor would remain the same, given the same load, and thus faster switching is better overall. Can you clarify how this causes more stress? Does it have to do with hidden inductance?
The higher the frequency the less capacitance you need for smoothing. That means you end up with small value caps carrying very high ripple currents.
@@LesNewell That's a good point. But what if you use the same cap, but just increase the frequency?
@@ChristieNel A designer wouldn't normally do that because a smaller cap is cheaper and probably has lower parasitic inductance. However if they did the stress would probably be similar. Of course with a switching circuit the current waveform is a different shape which can have an effect. The more you look into this stuff the more complicated it gets.
@@LesNewell Yes, it does. But for background, I have a prototype where I'm switching a MOSFET hard and drive a few amps into a heater, which was producing noise on my supply rails, so I stuck on a cap. I'm thinking that increasing the MOSFET frequency would reduce the ripple without affecting the cap lifetime?
@@ChristieNel If the cap is on the supply increasing the switching frequency could increase the average ripple current. It should however reduce the ripple voltage. If the issue is electrical noise you may benefit from adding a smaller ceramic cap in parallel with the bigger cap, say 0.1uF to 1uF as close to the transistor as possible. This will help catch the high frequency noise. You may also want to consider switching the mosfet a bit slower. This increases heat dissipation but generally reduces noise.
*Dixell* is what John Voight's character did in Midnight Cowboy.
Michael Dranfield recently shared a video of a common fault on Samsung flat screen tv sets.
th-cam.com/video/DREofE4WIvg/w-d-xo.html
A 10 ohm 1/16 W resistor was fitted in the supply line to the power factor correction circuit.
In reality it needed to be rated at 1/2W.
Of course over a 2/3 year period or less that 1/16W resistor is toast and the tv fails to power up.
This is the manufacturer deliberately making their product obsolescent.
I found the best thing to clear through holes was air duster from poundland
Yea, Dixie Normus !
Add about 40 minutes and 16 seconds you talk about touching the board and the pastor wires but you don’t mention the temperature. I’d love to have you, if you could share, tell the temperature that you use on your soldering iron. That’ll help, probably not just me, but a lot of us. Thanks. It’s not something you typically do but once in a while you do
Typically around 350C but I recommend going by soldering feel and not an exact temperature.
Where did you get that component tester at?
eBay.
You could have taken 2 seconds to actually Google "component tester". You get dozens of examples right away including this one.
Make some effort.
@@bzuidgeest No crap, but thats the whole point; there are literally hundreds of them if you look. I wanted the one Clive vouched for.
No need to be so presumptive. The whole point of having comments is interaction.
@@hgbugalou you could have done that visually.
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