All you need to know about Linear PSU (Power Supplies) To Build And Fix Stuff - Tutorial Guide

  Рет қаралды 78,039

Learn Electronics Repair

Learn Electronics Repair

Күн бұрын

Пікірлер: 117
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
*Please make sure to watch **59:05** * THE IMPORTANCE OF IMPEDANCE * This is the fundamental principle of all fault finding!*
@it-sd
@it-sd 2 жыл бұрын
Awesome job! Wonderful explanation, as always. You’re hand-drawn schematics and tutorials are the best-free, university-quality electrical engineering education.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
@@it-sd Strangely enough, when I think about it, this statement about source and load impedance is probably one of the most profound things I ever said on this channel 😊
@it-sd
@it-sd 2 жыл бұрын
Please know it didn’t fall on deaf ears. Well done.
@bimbim6565
@bimbim6565 2 жыл бұрын
@@it-sd ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp0pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp0ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp0ppppppppppppppppppppppppppppppppppppp00ppppppp0ppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp0pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp0ppp0ppppppppppppp0p0pp0ppppppppppppppppppppppppppppppp0pppp0pppppppppppppppppppp0ppppppppppppppppppppppppp0pp00p000pppll
@dfsilversurfer
@dfsilversurfer 2 жыл бұрын
@@bimbim6565 hey wake up. !
@it-sd
@it-sd 2 жыл бұрын
This is one of the best channels on KZbin for learning electronic repair! Thank you for all of your efforts!
@hullinstruments
@hullinstruments 2 жыл бұрын
Absolutely loving this content. It Took me nearly 10 years of constant full-time work to learn all of the stuff you’ve packed into a few months! Absolutely splendid! There’s been a real void for in-depth troubleshooting content on KZbin. Previous content creators were either “way to complicated extreme fancy pants stuff” or stuff that didn’t go into enough detail at all. There were a few creators like Marco reps and Diode gone wild who did sporadic troubleshooting projects but it was few and far in between Absolutely love and adore your channel and content. I discovered a similar KZbinr this week who goes by the name “magic smoke“. His content isn’t as well organized and packaged into a learning experience like yours is, but his troubleshooting videos are legendary, extremely long, and detailed. but still to the point where you don’t have to be an engineer to understand them. So his channel is really another super useful tool here on youtube I Would’ve killed to have had both of y’all’s content here on KZbin starting 10 years ago. But I’m just so glad it’s around now!! In six months you’ve covered damn near everything that I would expect to learn taking a 2 year troubleshooting course down at the college.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Thanks! I'll check out magic smoke too - I hadn't heard of him
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
edited I checked out magic smoke, that's a nice find. re Marco Reps sorry but I can't watch it, it just sounds too much like one of those trailers for films in the 90s and 00s - like 'It was a time for heroes'.... Actually I had another look at some of his videos and my comments abut the audio on Marco Reps was unjustified. 😊
@timothygolden5321
@timothygolden5321 Жыл бұрын
I do like electronics, but I enjoy listening to this man as much for his accent, as his details. The details do matter, though.
@kennyrmurray
@kennyrmurray Жыл бұрын
What a great job explaining this stuff to all us amateurs. I want to build a big power supply for my 90V DC motor from an old treadmill so I can build a nice belt grinder for my shop. I bet you’d get a lot of views if you did one like that and a single to 3 phase VFD for us Americans. Thank you!!!
@carlgradolph9676
@carlgradolph9676 Жыл бұрын
I don't know if you deliberately made mistakes or if you you just covered your blunders well. Either way, they provided opportunities to explain what can go wrong when building a linear power supply (or any other circuit) and how to troubleshoot, diagnose and repair the faults, which is valuable information indeed! Thanks so much for this video, from which I have learned a great deal.
@Martyn-ey9lw
@Martyn-ey9lw Жыл бұрын
Just found your channel, used to do instrument repairs for an electric company (NEEB), 500v I/R testers to 30kv I/R test sets to 60 Kv oil test sets and every thing in between, best job I ever had, still have an interest in electronics but don't get much practice these days. You have re-ignite my passion. Thank you
@nicklaspersson4687
@nicklaspersson4687 2 жыл бұрын
@1:26 I was very surprised by how the FBR was drawn. I thought it was drawn wrong or something but it is of course, correct. I just never ever seen anyone draw a FBR as asymetrical like that. It took me a good wile of thinking and redrawing to discover that you actually had NOT messed it up. Good exercise for me.
@davelowets
@davelowets Жыл бұрын
Yea, I always draw them as a diamond shape with all the bands on the diodes pointing to the positive end. The opposite side is negative, and the sides are the A.C.
@paulb4661
@paulb4661 2 жыл бұрын
Technically speaking, voltages from about 50 and up to 1kVAC and 1.5kVDC are classified as low, beyond that is where the fun starts, as even air becomes increasingly conductive. Nevertheless, even low votage can be lethal, or mildly irritating, depending on circumstances and the individual under test. Thank you for another great episode !
@davelowets
@davelowets Жыл бұрын
24vac across some sweaty skin can certainly be VERY irritating... 😬 ⚡️
@stevecoppin6396
@stevecoppin6396 6 ай бұрын
just started playing with this stuff , very informative. i used to do hydraulics for a living ... the number of times somebody would twiddle ALL the valves at the same time lol
@brano2yt
@brano2yt 2 жыл бұрын
the IC at 19:00 is AN6780 - general purpose long interval timer, contains oscillator + divider (15x flip-flop), maximum time: one week (datasheet can be found by "an6780 panasonic")
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Oh no - another HC4060 type timed charger circuit then. This design is getting tedious! lol why do they scratch the makings off?
@christianmusso629
@christianmusso629 Жыл бұрын
Great tutorial! I liked both the schematics explanation on plain paper and the actual verify with the scope.
@MsKelvin99
@MsKelvin99 2 жыл бұрын
I love this channel! glad the algorithms recommended it
@mickduprez9598
@mickduprez9598 Жыл бұрын
Awesome tutorial! I loved the structure of starting with almost nothing, testing along with your observations and gradually building in complexity to the final product, great stuff! A next step project that would be good to learn from is a simple amplifier, I get the gist of them but my understanding of how current and voltages apply at/through the base/emitter still needs work :) Thanks Rich 👍👍
@hiscifi2986
@hiscifi2986 2 жыл бұрын
I designed a few linear PSUs, and one 'fiddle factor' that I found useful was to make the main smoothing capacitor 5000 uF for every Amp designed output. So for a 20A psu you would need a 100,000uF capacitor. The mathematics used the formula C = I dv/dt. This gave a ripple of 1v on the Capacitor, prior to the regulating transistors.
@d614gakadoug9
@d614gakadoug9 Жыл бұрын
That is a very large amount of capacitance. One significant drawback to "excessive" capacitance is that increases the ratio of RMS current in the transformer to average current. This means you may have to derate your transformer's current rating more than you would with less capacitance.
@brikaf6001
@brikaf6001 Жыл бұрын
Absolutely the best explanation i've ever seen
@skysurfhf
@skysurfhf 2 жыл бұрын
You can use termal paste of CPU to see the chip numbers ( marks ) ... Is better than the alcohol 😜 ... Greatings from Portugal 🇵🇹🌟
@paulmuff9883
@paulmuff9883 2 жыл бұрын
I do like the way you explain things, please carry on your good work 👍👍👍😀
@neilappeal20
@neilappeal20 3 ай бұрын
I have a problem with low output causing blue screens, crashing and causing slow processing speeds. I'm suspecting mosfets. One of the groups I researched in suggested that the pfc maybe faulty causing lower mains voltage and higher duty cycles to keep output voltage. Got a bit o braindrain so I'll watch the vid again. Excellent vid again thanks v much 😊
@johnmarchington3146
@johnmarchington3146 Жыл бұрын
Thanks for a terrific video, Richard. I've enjoyed all the ones I've watched so far. A friend of mine in the computer club we both belong to (he's the president) had watched one of your ATX power supply repair videos and told me about it. I'm also interested in all things audio as well.
@m.kashefi
@m.kashefi Жыл бұрын
I really really enjoyed this video. Thousands thumbs up, Richard!
@badenmelhuish3215
@badenmelhuish3215 4 ай бұрын
hello from New Zealand. I just want to have a few words about the pin-outs of the 7812 and 7912. At first the the 7912 looks odd, but in fact they are the same as the 7812! Yes, Yes, they are the same. Have a look at the diagram of the 7812, which is the +input...pin 1, which is the --input …pin 2 and output is pin 3. Now look at the 7912, +input, again pin 1. --input again pin 2 and output pin 3. The difference between them is that the output of the 7812 is 12v above the --input and the output of the7912 is 12v below the +input. Its hard to see at first and you may think I'm nuts, but go through it carefully and you will see I'm right. Cheers.
@KB1UIF
@KB1UIF 2 жыл бұрын
I suspect the filament bulb was for loading the batteries for testing and cycling purposes. Filament bulbs make a much better job of a load rather than LED's that require current limiting resistors and will not work so well at the lower voltages, where as a filament will continue to load the battery until disconnected.
@wherami
@wherami 2 жыл бұрын
So far this is my favorite vid. Really enjoyed this one
@chadrussell2933
@chadrussell2933 2 жыл бұрын
Loads of info! Easy to follow! Great video!
@jmurph8906
@jmurph8906 2 жыл бұрын
Superb content Dickie. Chapeau!
@henrybartlett1986
@henrybartlett1986 2 жыл бұрын
Love your videos no matter how long.
@conwaynoel3715
@conwaynoel3715 2 жыл бұрын
Great vid, highly informative. Re ohms law, just cover the required value with your thumb !
@jordanch68
@jordanch68 2 жыл бұрын
A good source for a linear regulated power supply is one of the 'SOLA' type industrial power supplies. In stock form they are available in various voltages from 5-24v DC in various amperage values. The transformer outputs between 50-65v AC if you want to do your own regulation/rectification circuit.
@TheEmbeddedHobbyist
@TheEmbeddedHobbyist 2 жыл бұрын
A nice dual bobin transformer there, great for mains isolation as the mains and the output windings are on there own bobin so no chance of ever touching. Unlike a lot of the imported units where the isolation is just two layers of enamel coating, putting the input mains and the output low voltage closer than a gnats balls.
@andymouse
@andymouse 2 жыл бұрын
Squeak!
@englishrupe01
@englishrupe01 Жыл бұрын
How on earth did you manage to measure the proximity of gnats' testicles....or are you referencing a research paper? And how many gnats were injured or suffered in the making of said examination? I have often tried but failed after said subjects expired when my micrometer slipped. ;-)
@TheEmbeddedHobbyist
@TheEmbeddedHobbyist Жыл бұрын
​@@englishrupe01 i have a book called "100 and 1 things about a gnat you wished you had asked your mum" ;-)
@ElectronPcRepair
@ElectronPcRepair Жыл бұрын
Thankful for your efforts to teach us
@jonsdiagnostic5879
@jonsdiagnostic5879 Жыл бұрын
Thank you so much for all you do!
@BjornV78
@BjornV78 2 жыл бұрын
11:12 you can make a "KGB screwdriver" yourself by using a flat screwdriver, and use thin cutting wheel on the Dremel to make the gap. 12:51 That small incandescent light bulb can have 2 purposes, as a "charge" indicator, and also as a current limiter, because those small SMD resistors alone on the back can't limit the full current that the transformer wants to deliver to a flat battery.
@brano2yt
@brano2yt 2 жыл бұрын
Actually small bulb has a function in first charging slot, after switching the switch to check/TEST position. It loads the battery and by stable or fast dimming light you know the state of battery. After charging a good battery it should shine continuously bright.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
@@brano2yt Yeah it seems that charger has a battery test function - and most likely the light bulb is the test load
@T2D.SteveArcs
@T2D.SteveArcs Жыл бұрын
Should have used a full-bridge rectifier across the two white wires and black would have been CT or common you would have had plenty of voltage in that case to use 7815 and 7915 .. the scope trace looked that way because you had no load on the diodes and they need a load to switch properly, the 1/10M loading of the scope probe often isn't enough... Steve
@lrdisco2005
@lrdisco2005 2 жыл бұрын
How to learn about electronic devices. 1. Watch every video on this channel. 2. Buy a multimeter and an isolation transformer. 3. Find broken stuff, take the lid off and start taking readings.
@kwpctek9190
@kwpctek9190 2 жыл бұрын
Bipolar supply is possible on single output AC transfo's. One wire is 0v (common rail), and the other splits to 2 opposed diodes for half-wave to a pair of larger el-caps for both + and (-). Image look-up *many simple 6V power supply*
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Thanks, I'll have a look
@brano2yt
@brano2yt 2 жыл бұрын
The circuit is called "full wave voltage doubler", it has the disadvantage of half wave rectifier, but is simple to build. But on center tapped transformer you can use bridge rectifier on the opposite secondary "ends" and output capacitors from both plus and minus to center tap. So you use both half waves to charge both caps.
@kwpctek9190
@kwpctek9190 2 жыл бұрын
@@brano2yt True, I had forgotten that. Many multiplier cct's (2x 3x 4x etc) use long strings of NP caps with diodes acting as stage blocking to prevent backwards discharge. I think a cheap 20w @ 16v door-bell transformer would be a good choice to about 200ma. They're also usually class 2, so safer is better.
@mariushmedias
@mariushmedias 2 жыл бұрын
A few observations ... Didn't see any mention of the idle AC voltage being much higher than AC voltage under load. Very low VA rated transformers will often have an idle voltage 15-30% higher than "under load" voltage. Also, when choosing rectifier diodes and output capacitors, keep in mind that your AC mains voltage is not fixed, depending on time of day it could vary a lot... it's not uncommon to have 250v AC at 2-3 AM where I live, where the default AC voltage is 230v. So account for that, assume the secondary output could be at some point much higher than expected. The 1uF electrolytic on the input in your circuit is kind of pointless. For decoupling, it would make more sense to have ceramic capacitors there, in the 0.01uF/0.1uF/0.47uF range. Electrolytic capacitors filter some frequencies, ceramic capacitors are good at other, so with two different types of capacitors you're better off. One other observation : pay attention to datasheets but keep in mind when those datasheets were written also. For example, a lot of datasheets will say "a 10uF tantalum capacitor on the input would suffice" - they say tantalum because those had reasonably low ESR and 10uF ceramic capacitors were more expensive when the regulators were invented and datasheets were written. Nowadays, 10uF electrolytic or solid (polymer) capacitors exist with specifications much better than tantalum capacitors. So you could use a 10-47-100uF electrolytic on the input that's cheaper than equivalent tantalum capacitor (and you don't risk holes in circuit board from tantalum capacitors going up in flames) Some regulators have specific requirements that must be respected. For example, a "jellybean", very common regulator series, 1117, made by various companies, requires a capacitor on the output with ESR between 0.1 ohm and 1 ohm. Some manufacturers make them compatible with ceramic capacitors, other brands don't... so some people add a 0.1 ohm .. 0.22 ohm resistor in series with a ceramic capacitor when they don't want to use an electrolytic capacitor - even with electrolytic capacitors you have to be careful - some series of capacitors have less than 0.1 ohm ESR at capacitance values below 100uF.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Thanks for the in-depth explanation on capacitors - I openly admit (and accept) I am much more of a fixer than a maker but one of the great things about this channel is that subscriber put their 10 cents worth in to the discussion and we all learn in the process, me included 🙂
@d614gakadoug9
@d614gakadoug9 Жыл бұрын
Beware of modern high C•V product ceramic capacitors. Some of them have extremely large-magnitude negative voltage coefficient of capacitance. Your nominally 10 µF capacitor rated at 16 volts might be down to 3 or 4 µF or less at 10 or 12 volts. If you want something close to nominal capacitance you may need to operate such caps at a voltage so low you are better off with a "better" cap with lower voltage rating in the same physical size.
@HnsxToP
@HnsxToP 2 жыл бұрын
Thank you for the lesson sir!
@Dutch_off_grid_homesteading
@Dutch_off_grid_homesteading Жыл бұрын
Heya that is a nice way to make some project indeed
@gregwmanning
@gregwmanning Жыл бұрын
Just found your channel. It is very interesting thanks. Have you discussed the Isolated Test bench in another video, if not I would find that explanation informative.
@KB1UIF
@KB1UIF 2 жыл бұрын
Maybe you could use the lower voltage part of the transformer as a single 5V supply instead of a plus and minus supply?
@andymouse
@andymouse 2 жыл бұрын
A nice watch...cheers.
@daz41262010
@daz41262010 2 жыл бұрын
excellent videos coming from your content :)
@jamescollins6085
@jamescollins6085 2 жыл бұрын
Are you open to recording some footage at the car boot sale as well? I find it interesting to look around virtually.
@alanrichardson1672
@alanrichardson1672 2 жыл бұрын
Perhaps you should mention voltage and current transformers are generally rated in VA
@AllTheFasteners
@AllTheFasteners 2 жыл бұрын
The irritating screws might be to do with certification, depending on the interpretation of the standard. I can see that putting such screws in might be a way to make a stronger argument that hazardous areas are not accessible. Also the possibility that the assembly company is already tooled up for the particular screws, maybe for products where they have a more legitimate use.
@ralphj4012
@ralphj4012 2 жыл бұрын
Educational, as always. Not sure if you tested current, voltage etc without the dim bulb in circuit. Probably makes little difference at these relatively low currents, but worth a check.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Yeah I bypassed the current limiter off after the first test
@uksuperrascal
@uksuperrascal 2 жыл бұрын
The Lamp is to test a 1v5 battery before charging, if the lamp can be lit at any state of charge of the battery to be charged, then any battery will charge even nonchargeable AA OR AAA batteries the manufactures recommend you do not recharge, you just have to not leave them on charge, A for to long and B not unattended or to monitor battery heat. Most AA & AAA non rechargeable batteries will recharge 5 to 10 times with a 1 to 2 hour charge of 2 Volts at 100mA to 200mA's.
@michaelconnolly748
@michaelconnolly748 3 ай бұрын
You assumed you have one secondary winding. You may have two secondary windings, with the center tap linked together of both windings. The center tap will probably be zero volts on the battery charger.
@jonathandyble6619
@jonathandyble6619 2 жыл бұрын
Hi Richard great vid. Can you tell me if the kaiweets km601 you reviewed has adequate resolution to work well with the £1 sort finder you built? Thanks.
@bloothedog4443
@bloothedog4443 Жыл бұрын
The oscillator setup on that 4060 (pins 9, 10, 11) seems different to me (as many things do 😆). Looks like 11 goes to the usual 2 resistors and probably a capacitor somewhere, but also a couple of transistors?
@theshemullet
@theshemullet 2 жыл бұрын
You should add a tip button to your videos
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
I do have patreon and paypalme for donations if anyone feels inclined, it would be much appreciated as videos like this one take about 8 hours (one full days work) to get the recorded material and about another 4-5 hours in post production editing to make it all coherent and get the audio level reasonably balanced throughout. Even a €1 donation makes a difference to me. You can send donations via this link www.paypal.com/paypalme/youtubeLER You can make regular monthly donations via this link (until cancelled) www.patreon.com/learnelectronicsrepair
@theshemullet
@theshemullet 2 жыл бұрын
@@LearnElectronicsRepair I dont know how difficult it is but I have seen other channels with a tip button. it makes it very easy as anyone can just send you a tip without a sign up or anything. Might be worth you adding it in.
@theshemullet
@theshemullet 2 жыл бұрын
@@LearnElectronicsRepair actually its called a thanks button
@theshemullet
@theshemullet 2 жыл бұрын
Also it would allow passing viewers just give you a few quid. It might also be useful for you to see what videos you do that are more appreciated. If you get a flat patreon fee, then you dont know which vids people really like/want from you. So it might help with you working out the vids that are most useful to people. its handy to give a like but if someone is willing to give a few quid for a video you know that thats the content that is most appreciated. Just an idea. Hopefully you will add it so we can give you a few euro for vids that we really get the most out of. Thanks for all you vids.
@theshemullet
@theshemullet 2 жыл бұрын
Donation given. Look forward to your next videos. Oh could you do a video explaining voltage drop
@clifforddicarlo9178
@clifforddicarlo9178 7 ай бұрын
Guerrilla warfare electronics !
@davidmonk7773
@davidmonk7773 Жыл бұрын
Hi Richard, what would make one of the bulk capacitors hit 55v and the other correctly 17v after the rectifier diodes? The transformer is correctly outputting 20v 0v 20c 12v 0v pre rectifier
@ElectronPCFix
@ElectronPCFix Жыл бұрын
What else can I add to make it up to 30 v 5 amp variable Linear DC Bench power supply
@kiklop2715
@kiklop2715 2 жыл бұрын
you really need to make oscilloscope for repair tutorial
@opticwiddly5263
@opticwiddly5263 2 жыл бұрын
I second this
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
I will do that 🙂
@jamesmdeluca
@jamesmdeluca Жыл бұрын
Greetings: When displaying the scope image, set your trigger to LINE, 2ms/division, and adjust trigger for a stable display, otherwise your setup is just wasted as it js difficult to follow your discussion.
@Mark_C1
@Mark_C1 2 жыл бұрын
23:40 A+B is PNP, is the way I managed to memorise the transistor types on those T092 types
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Nice little mnemonic
@Martyn-ey9lw
@Martyn-ey9lw Жыл бұрын
The way I remember NPN and PNP from schematics is NPN is Not Pointing iN refering to the emitter, probably doesn't make sense to any one else but that is what sticks in my mind.
@BoB4jjjjs
@BoB4jjjjs 2 жыл бұрын
😎 👍
@surgingcircuits6955
@surgingcircuits6955 2 жыл бұрын
So we figured out that we need a 120-ohm load for our desired test of 100mA. 12v x 0.1a = 1.2-ohms. Since the resistor/load is connected to +12v on one side, and -12v on the other, wouldn't it be getting 24v? Thx.
@surgingcircuits6955
@surgingcircuits6955 2 жыл бұрын
Seems like the resistors should have been in series for the load.
@davelowets
@davelowets Жыл бұрын
1:28:05 It is a.... "FOOL BRIDGE RECTIFIER!!"
@stef2797
@stef2797 2 жыл бұрын
the led's on chargers don't light up till a battery is placed in them to join up the curcuit
@AllTheFasteners
@AllTheFasteners 2 жыл бұрын
Perhaps a filament bulb was used because it was on the 240V AC side.
@weerobot
@weerobot 2 жыл бұрын
Cool...
@davelowets
@davelowets Жыл бұрын
Next up..... A dual-polarity power supply, that provides at least 3 watts of output current, with perfect symmetry on both rails, stable driving low impedance loads, and, oh yea, it must run off a single polarity 12 volt battery... Yes, I know that there are specific I.C.'s available that do this, but this supply needs to be made from discreet components.. Good luck.... 😬 😜
@glennhuel-qz2cb
@glennhuel-qz2cb 7 ай бұрын
can you suggest a 40 volt dc to 5 volt dc 300 milliamp off e battery transformer circuit end ....
@akcoord9615
@akcoord9615 2 жыл бұрын
sorry but this smart meter so you do not have to switch every time you measure ac/cd ampere or volt or ohms thanks for the great videos
@CliveChamberlain946
@CliveChamberlain946 2 жыл бұрын
Be careful not to over voltage or reverse feed tantalum capacitors. They explode with fire. They used to be all the rage, but today 99% of the time MLCC capacitors are smaller, better and safer.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
That probably explains why I have a whole bag full of them found for almost nothing at a Ham Radio rally lol
@CliveChamberlain946
@CliveChamberlain946 2 жыл бұрын
@@LearnElectronicsRepair 😂Now there's an idea for one of those video shorts! "The reverse polarity special" debuting at a shop near you! (just keep a fire extinguisher handy)
@Martyn-ey9lw
@Martyn-ey9lw Жыл бұрын
@@CliveChamberlain946 Yes please
@ambersmith6517
@ambersmith6517 2 жыл бұрын
i have a scope that has a problem just like yours it just sits taking up space i did find the problem its been so long but its not any thing big
@davidhollfelder9940
@davidhollfelder9940 Жыл бұрын
Tantalum cap in reverse .. we could have seen it flame up.
@dahmanus2002
@dahmanus2002 2 жыл бұрын
This kind of devices lights up when you put a batteri to charge .
@corel965
@corel965 2 жыл бұрын
I startet to watch this chnl from Sorin, but it's so hard to find LINEAR PS without protection can anyone advise me some of them ? Thanks in advance ! :)
@willsmith4584
@willsmith4584 2 жыл бұрын
What country is this? It has the same plugs we have in South Africa... I'm gonna guess australia simply because my stepdad has the exact same laugh. He is from Australia
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
Gran Canaria (The Canary Islands) - part of Spain. I'm originally from the UK
@wherami
@wherami 2 жыл бұрын
Its to keep out the average muggle. Same level of security that keeps average muggles out of operating systems. It defeats and deters 90 percent. Per your special screws comment
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
That would make sense if you couldn't buy these little screwdriver sets for almost nothing from almost everywhere. Anyone who does any sort of DIY (and that's most of us) must have a set 😏
@wherami
@wherami 2 жыл бұрын
@@LearnElectronicsRepair you underestimate how lazy the general masses are. There is little to stop the motivated and dedicated.
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
@Mr Guru haha I was clearly ripped off LOL 😆
@LearnElectronicsRepair
@LearnElectronicsRepair 2 жыл бұрын
@@wherami Very true 😁
@QARepair
@QARepair Жыл бұрын
👍 but you speak so fast or if exact normal and then suddenly very emotional fast😅, sorry, I barely understand, I'm not english
@johnboothman1235
@johnboothman1235 Жыл бұрын
useless waffle
All You Need To Know About Logic Gates To Fix Stuff - Tutorial Guide
1:01:42
Learn Electronics Repair
Рет қаралды 20 М.
Twin Telepathy Challenge!
00:23
Stokes Twins
Рет қаралды 121 МЛН
Don't underestimate anyone
00:47
奇軒Tricking
Рет қаралды 21 МЛН
Как Я Брата ОБМАНУЛ (смешное видео, прикол, юмор, поржать)
00:59
{1243} Decoding SMD Ceramic capacitor to voltage and capacitor value
15:13
Haseeb Electronics
Рет қаралды 41 М.
Linear DC Power Supplies - Designing & Building Custom DC Power Supplies
1:12:39
Design Your DIY Power Supply! (+/- 12/15V)
21:04
The AudioPhool
Рет қаралды 58 М.
Everything You Need to Know about MOSFETs
35:54
ElectrArc240
Рет қаралды 200 М.
Samsung 860 Evo SSD Repair- Data Recovery Lab said it wasn't possible.
14:44
Power Supplies and Electronic Life-Hacks (ElectroBOOM101 - 009)
14:37
ElectroBOOM
Рет қаралды 1,6 МЛН
All You Need To Know About CAPACITORS To Fix Stuff!  LER #182
58:57
Learn Electronics Repair
Рет қаралды 157 М.
Twin Telepathy Challenge!
00:23
Stokes Twins
Рет қаралды 121 МЛН