Відео

Hello, yes this can be done by using the dac 0-5v output instead of the 10k VTR potentiometer, cheers

@@KonstantinGrigoriadis thanks a lot 🌹💖

Hi Bjorn, Yes the Heartsicks are very cheap, but only for medium to low loads. The SMD 12x12 Inductors are made by so many Companies (Würth, Sumida, TDK, Bourns, and many Asian Brands,etc) its just another CN company that makes it :-) These of course from ali I would not use for Prof design. Cheers

Hi Dave, Yes :-)

Hi Alesaandro, thankyou for the info, haven't seen that AN-86 (A Standards Lab Grade 20-Bit DAC with 0.1ppm/°C Drift) from 2001 yet, yes that makes sense :-). Cheers, Konstantin

Onois tous C2 & C3 ? Ine 10nF. Xeretismata

@@KonstantinGrigoriadis Ευχαριστώ πολύ.

Parakalo !

Thankyou, The Drive Transformer has a dedicated winding as seen in the Schematic where the whole Primary Switching current goes through, but that's not what it make self oscillating. The Secondary Aux winding is that what powers the Center Tap of the Driving transformer, V+.

@@KonstantinGrigoriadis Thanks! Again it’s hard to visualize what you are talking about without actually seeing the transformer and where what is what. This video was of interest to me mainly because I am interested in learning about self-oscillating circuits and how they work.

​​⁠Hi Brent, I have a link in the Video Description, that explains detailed and thoroughly how this Self oscillating Startup Design Works(again its self oscillates ONLY AT STARTUP to produce the V+ for the tl494, after that the tl494 takes over and the self oscillation Stops. Its the same design just with a different controller IC . Its not the easyest reading :-)

@@KonstantinGrigoriadis Thank you for the clarification and posting the detailed description.

No Problem, but the link was in the description since I uploaded the Video and I explicitly mentioned that in the Video too :-))

Hi Maksim, Please note that Fine & Coarse Labels need to be swapped in the Circuit I Shown, Typo :-)

Hi, correct! Gain=R15/R14, so Labels are swapped. Thankyou!

Thankyou Bjorn!

Hi Ron, is the output noise of those psus when powering your ham equipment acceptable or you use 2nd stage Filters, cheers

Hello, Thankyou!

Hi, Which one ?

Hello, Bcs it starts to Produce Errors when get hot, would check the Voltage Regulators that are attached to the Metal casing as Heatsink. Eventually due to Vibrations the Thermal Connectivity to the casing is not given anymore. I m Video you can see the Regulators I mean, they are glues with Hot-melt glue in place and use additional a Clip.

@@KonstantinGrigoriadis Thank You very much for advice, I rather attempting to fix cars ECU's with some rate of success, without spending too much time with it, where diagrams and pinouts are widely available. Also test it at the car, using live data, oscilloscope or thermal camera if needed is way more helpful method, than playing with naked ECU. I thought voltage regulator would cut off and stall the engine while running, unless there is know issue with them, engine can run with no issues all day, but problem appears only when engine is shut off by user and then won't start / crank again, like rebooting immo along bunch of errors on dash, upto ECU cold down again, also I don't have diagnostic tool for farm/building vehicles. I didn't even know how to tear down this ECU , if is glued inside, Too many cons at the time. I also thorough is some relay or mosfet problem, or thousands cold soldering joints.. Customer with someone help make a test and heat up ECU only in cold day, and that's pointed to ECU mulfanction.

Thankyou! Please Contact me via Email, my Email is in my Channel Description, at the Channel start Page right to my Picture. Cheers

Thankyou, NO ! the system self oscillates at Startup till the Aux (V+) voltage is build up to power the tl494. After that the tl494 takes over, I never said its an self oscillating system, I said and and wrote its self oscillating at startup. Additionally it Produces the necessary base Current needed to drive the BJT Switches! Read the link in the Video description!

Gia sou Thoma, Yes I have quite some stuff :-) The Mailbox video was not much of Interest in means of Views, but I will continue it, I already Have another Video for that made. (these are easy Videos :-). Xeretismata , Ntinos

what do you mean ??? Include it where ? the schematic I show is a reverse Engineering of the China Module, not my Design, it has no regulation at all... its open loop. My Design will have U/I regulation with High Side Current Sensing and is not based on a SG3525.

Hello, Sorry no, because I will not Tear-down(Destroy) the Transformers

It is self oscillating at startup to produce the voltage needed fot the tl494 , after that the controller takes over, if y dont believe desolder the tl494 , i showed in the video and provided a link that explains it in depth, the current boost is also needed to drive the power bjts…

@@KonstantinGrigoriadis Interesting, have to admit I have not seen this explanation before, will compare with ATX PSU which uses this topology and see if they follow same way of working...

Hello, it should be an ATX with NO dedicated AUX voltage Source, or just a S-360-12 like the one I showed here. The Current amplification through the GDT is necessary at all these PSU's thtt use Power BJT Switchers, due to the Base Current needed. (or a more Powerful driver stage). In the Schematic you can see that the Voltage from the AUX Secondary winding of the Power Transformer is rectified and is allied to the Primary Center Tab of the GDT (among the VCC of the TL494 and the driver stage). Here the Detailed Explanation: ludens.cl/Electron/PS40/PS40.html (from my Video Description). From the Description: "The power supply will oscillate freely for only a few cycles, because D17 is already charging C32 and C33, powering up the control circuit. As soon as this circuit gets enough voltage, it takes over the control of the power oscillator" and this is what I mean with selfoszilating, the Startup Circuit !, but if there is no Controller IC that takes over, it will continue selfoszilating, I proved that with removing the TL494 for the Board and I had a output Voltage of 6V. Somehow the Statup Voltage have to be generated to Power the Controller! I am Speaking here about the Power Supply I showed in the Video the S-230-12. The Controller resides electrically in the Secondary Side, if it was on the Primary then it could have been powered from the Rectified mains (via high Vaule Resistors), which is done in most small Offline Power Supplies (Flyback Notebook chargers, etc).

@@KonstantinGrigoriadis Yes I checked again and could see two different versions, and the one which don't have SB power supply indeed is having additional resistors R2 and R6 as per description link you provided... Now the only open question for me if GDT are identical between two variants, in self-oscillating case it is mentioned that GDT should be enetring in saturation mode before main tr-r do... Thanks for this case, I did learn some new information :)

Hi Gene, Thankyou. I remember seeing this Design in 80's Industrial Process Computer Power Supplies.

Thankyou!

Thankyou, I will eventually upload it at pcbway or at jlcpcb, Cheers

Hi Gordon, the use of a small aux voltage converter is standard design on all industrial prof psus I have seen. Yes they run all the time bcs when right design they dont contribute to additional noise, not even in these low cost designs.

Hi Paul, Please Contact me via Email to send you the PDF Schematic. Cheers, Konstantin

But its the only thing that those 2 have in common :-)

@@KonstantinGrigoriadis I hope everyone knows that. BTW, MW supplies were made in Taiwan, but now they are like others "made in china" 😭

Hi Paul, yes like almost everything the MW Psu's are made In china BUT matching the MW High Standards. The misconception is , that bcs its made in China its crap, NO WAY, its just they Produce for you what you are Willing to Pay :-) You Pay for a Cisco , Huawei, ZTE, etc. Equipment you will get High Quality with all real Makings and tests, you are will to pay almost nothing , you will get something that more or less works in the Cheapest way (Repurposed Parts, Questionable Design, etc). Lets don't forget that almost everything is produced there :-) I have made many Designs In China with Immaculate results, very competitive Price(but more expensive than Ali stuff) with Good Quality Parts (that again are Manufactured in China :)

Hi, Please contact me via Email to send you the pdf, Cheers, Konstantin

Hello, Please Contact me via Email, my Email is in the my Channel Description, at the Channel start Page right to my Picture

Sorry, I can't find your email address!

I explained where my Email is at the Description of my Channel Homepage.....Anyway write me your Email, I hope UA-cam will not delete it.

Look how to find the Email of every channel on UA-cam..... support.google.com/youtube/answer/57955?hl=en , you could have searched that by yourself too!

Hello, Thankyou! Please contact me via email to send you the schematic, Cheers!

Hello, Please Contact me via Email, my Email is in the my Channel Description, at the Channel start Page right to my Picture

Hello, Thankyou, please use the Email in my Channel Description to contact me and I will reply you with the Schematic. Cheers

Hello, Please Contact me via Email to and I will reply you with the Schematic, my Email is in the my Channel Description, at the Channel start Page right to my Picture

Really ? Its a design from the 80‘s , and this is how it creates the startup voltage nessesary, pls read the link in the video descriptio on how it works in detail. And yes its the design of old atx psus of the 90s early 00s era that use bjts as switchers

Thankyou!

@@KonstantinGrigoriadis I know you might be bored with power supplies but the truth is: EVERY device has to have some kind of power supply. Some people just don't get it 🤣 you can make 100 different devices that do not share even single component, or piece or concept, but each of them has to have power supply or power management 😉 that's the mostly used piece of every device. Maybe not the most crucial one, but the most common. Just an idea: maybe in some video you could share your thoughts on when you should use which design? (cost efficiency, power efficiency, stability of delivered V or I, power delivery). That would be great and valuable to everyone 👌

Hello, Thankou, well I am not bored in General with psu‘s just these low cost ones, I am in the power electronics prototyping and that is fun :-). Yes these are reverse Engineering Videos to explore the design and help people with repairs bcs the are used extensively in parts of the world, not design videos. But its a good idea to perhaps include some thoughts about it in the future, cheers, Konstantin

Hello, yes, the mcu is not in the regulation loop, to slow and to Unpredictable, just for setting and showing, typical digital controlled psu design, just too diskrete

@KonstantinGrigoriadis the analog comp can generate an interrupt so you would expect instant switch off of any further over current or over voltage. Very interesting to see this digital controlled psu which gives a very rough idea how the main features are accomplished. I am considering building a prototype with a stm32 and ie a uc3843 or similar chip but it has been very hard to find any information or design up until I saw your video. Thanks!

​@KonstantinGrigoriadis and after going through your video (several times...) it is not clear to me how they actually regulate the selected voltage or current control. There is only a kind of emergency voltage and current control using opamps so that in case of the mcu crash or freeze it won't go into a total runaway. Or or is the regulation done when the over voltage or over current opamp comparators go high that the 2 parallel transistors in the power supply will be disabled???

​​⁠hello, even with interrupts this is to slow and unpredictable for analog regulation, I do alot with mcus hard and software, there are nested interrupts, etc. I never have seen (and probably never will see) ca mcu control the analog loop except for testing with really high speed mcu‘s that break the bank :-) massively !

The 2 opamps with the ored diodes at the outputsare the regulation, its a typical u/i analog design regulating the current fed to the driver transistor of the power board, ocp and ovp hare handled from different opamps

Hi Dustin, yes I often find Interesting stuff there :-)

Hello, in my opinion an MTBF statistic is very difficult bcs you never know hat parts you will have in the psu you receive, can (and mostly will be) salvaged ones from ewaste, like showed in my video about the 300v 1.6a version of a similar psu.Its the pure definition of Luck :-) but that is to expect based on that price….(still with these shortcomings they are ok for non critical usage) that is unbeatable. If lucky they will work a long long time.., Cheers

Hi Ivan, well the Price between the Probably Salvaged BJT's and Salvaged Mosfets is same, even if not Salvaged the Price difference is neglectable. The Price though for a Dedicated Flyback controller IC and an Dedicated Flyback Transformer + additional needed Parts, is higher that a questionable made Special GDT used here

@@KonstantinGrigoriadis Whatever floats your boat mate... This solution is the cheapest possible, and your (or mine) opinion wont change it. Would I design it that way? No. Would I use it in some of my projects? No. Is it the cheapest piece of junk that any Joe woud use to power up LED light or something? Yes. Also this power supply wont even pass the EMC tests in any serious country. It lacks PFC, noise filtering and a bunch of stuff...

Agree 100%, I like the wording: whatever floats your boat, never heard that before :-)

Hi, Thankyou, well the TL494(594, etc.) are 80-90's Chips but still not bad when used correctly. 1) Primary reason is Cost, the cost is way under 1 USD per pcs, that make them attractive 2) further they are available in very large quantities from Asian Brands, no shortage there :-) 3) There are Proven working Designs and Layouts. (Costs again) The TL494 was introduced by Texas Instruments in 1983 and by around 2000 was the industry standard for push-pull, transformer-coupled SMPSs Cheers, Konstantin

It is an Old Outdated Design, whatever your Opinion is! I didn't said its bad, the Fact that the whole Primary Switching Current goes through a Tiny GDT makes it bad! We are not dealing with a LED Driver here, that a is 360W PSU! Further, I would never Design this way anymore (I am in the Power Electronics Prototyping) Its a Design of the 80's era, even the more recent CN's PSU's use a dedicated AUX PSU Chip, see my other Videos.

@@KonstantinGrigoriadis I understand you but this PSU nowadays is used for a large LED Driver like LED ADS frame and is meant to do only just that is not meant for electronics and on the same sticker some PSU have state LED Driver PSU or on the package but people use it for everything even some phone charger is dangerous in the design, and if you ask me i prefer classical transformer + bridge rectifier + capacitor for filter yes it's huge but more secure and stable but everyone has it's own opinion. 😀

I agree, cheers, Konstantin