Building a Lab Power Supply with a Discrete Linear Regulator
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- Опубліковано 23 лют 2017
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Paypal-Email-Address: inventordonations@gmail.com - Наука та технологія
The first video about this power supply build can be found here:
ua-cam.com/video/J3N6RX_wAJg/v-deo.html
Nice work, good solid fundamental engineering principles. Well done! Bravo!
That Czechoslovak TESLA resistors at 23:25 :D
Hi
Any chance of doing a video for a linear power supply for audio equipment such as dacs or headphone amps as they are so very expensive?
Kind Regards
What is the power draw of a headphone amp? I reckon it's below 5W
If it is, a simple 78xx/79xx + Filtering circuit will be enough. Don't be audiophooled :D
A DAC is typically very low power, 1 or 2 W. Again, a 78xx circuit is more than enough.
You would need to tell me the input voltage of the DAC or headphone amp, the input voltage of your power supply you wish to power the load with (must be 3-4V higher than the voltage of the load) and the power draw of the load.
Linear power supply (non audiophool kind) are very cheap, 10-20€ max for a high powered one including transformer.
Hello Guys Can any one give me more detail or in a word explain how The voltage dividers of Voltage regulator amplifier and current regulator amplifier works in this video?
Another question says what's the function of the two diodes attached in parallel between inverting and non inverting input of voltage amp.reg. ?
Another thing how the current source with those amplifiers working to control 30 output voltage and current with a low +5 volt only as you because of presence the load on the emitter of transistor to maintain a specific voltage through this load you need to provide that exact voltage +0.6v so 5 volt ignoring sinking path of op amps will provide us 4.4 volts at the emitter load whatever the collector voltage is ?
Thank you .
Where you learnt your electronics is one question, but of equal fascination to me is the source of your impeccable english pronunciation and grammar. Superlative in both fields.
I can't believe it had already been 4 years since the build of this power supply. I remember how excited I was to watch the build. I watched it multiple times back then, I was still in highschool. Now I am in my 3rd year in University. Time does fly. It's unfortunate these types of videos don't receive as many views as the others.
Some additional remarks: Since the LM324 contains four op-amps, it would have been better to write down "1/4 LM324" instead of "1/2 LM324". This mix-up happened because I originally wanted to write down either "1/2 LM358" or "1/4 LM324". These two ICs are virtually identical, only that one has two and the other four integrated amps. The LM358 can be used just as well. I simply didn't have one lying around and basically "wasted" two op-amps. With a cost of around 30 cents for one LM 324, this shouldn't be a big issue though :D. I also tried to use the two remaining op-amps in conjunction with the meter for the current measurements, but since I ended up using an "active current sensor" with an integrated amplifier, they were'nt needed in the end.
On antother note: I have to stop using the phrase "so called" when I refer to the corret name of something. It's just a German thing, because we have a very similar phrase that can be meant both positive or negative regarding the validity of the used term.
Very Nice Video indeed. But could you perhaps provide an updated schematics maybe. It looks to me that you are using V03 as both ground potential and voltage output.
Halo Gerolf, I wanted to let you know that this is perhaps one of my favourite videos on UA-cam. I have a very similar audio amplifier and I have been planning my own bench power supply following this video very closely. I wanted to ask though: at around 20:38 you show a schematic in which the current limiting circuit uses four 1K resistors. There is an arrow pointing to nothing at the bottom of these resistors. Are these connected to the output? You meantioned them being in series with the darlingtons and in parallel with the voltmeter. Thanks!
I used an LM741, which is a single op amp roughly equivalent to each in the LM324. :)
I know that it looks confusing, but it is correct. The minus side of the rectifier of the first secondary winding is ground. While the minus side of the rectifier of the SECOND secondary windings is V03. You see: The linear regularor circuit needs +5V and -5V volts in reference to V03 and not +5V and -5V in reference to ground.
Now I know why you do the scrapyard videos and old tool restoration. Mental health.
I'm so with you. I'm trying to learn welding. It's so zen compared to work.
God damn, oldschool TPAI style, love it!
It's amazing how stable your outputs are. Great work man🙌
Only after watching this and other videos MULTIPLE timed, I grasp the genius of your design. Spesifically the dioded on the output of the 2 op amps.
Well done.
I have watched this series many times and it helped me a lot.
Thank you
Thank you for making this video series. It is clear you have a passion for teaching electronics and take the time to make them. I wish I had 1/10th the talent and capability you display in your projects.
Thank you for making them. I know it takes a lot of time and energy to produce them.
This is still my favourite of all your videos. When I first watched it, I only just understood what you were saying.... after many re-watchings I nearly understand it...... good way to learn about power electronics. I'd love to see more videos with this level of technical complexity.... although not every week, I don't think either of us could manage that. ;)
Keep up The Great Work.
Excellent video, the stability of your build is brilliant - much better than I had expected. I'm just geting myself organised to try to build something similar, so your efforts are greatly appreciated - thanks!
That was bloody brilliantly done. I love what you done with the oppamps. Class🙏👏
Excellent results from an LM324. It seems to be a reflection of the time and care spent in properly sizing components and testing repeatedly. I built a very similar circuit last year based on an TL072 and a single 2N3055. I found the response of the FET input opamp far better than I needed in that particular circuit. Thanks for sharing. I can understand how many people who view this may feel uncomfortable with the details but I've enjoyed it. Too bad you didn't post a 3 hour version of this video including more of your development process. Yeah, I'm that guy. Thanks for sharing.
I was thinking the same thing. I'd have liked to have seen some more details of the experimentation. But a lot of people can't remain focused for that long. We're living in the age of ADHD.
Lots of “old” power supplies use op-ams like LM741 and its dual and quad versions and still work very well. The effort is spent in applying the parts so that they perform per the specifications of the application. Those diode gate circuits are rather popular, and they may be indeed called gates since they perform a nonlinear function with sharp transitions. Together with the op-amps, the circuit works like an analog computer solving a set of linear inequalities.
For a dual amplifier the LM358 or RC4558 can be used. The second choice has a greater bandwidth product of 3MHz and is used in audio applications as well.
An excellent description of the operation of the regulator! Thanks!
Thanks again, mister! Your videos are so informative and well made, and I appreciate the honesty about how it touches you personally to make the videos also. Much appreciated!
im not skilled enough to bulid that, kudos to you sir!
Love this design and style with the big analog meters. Am I the only one who thinks He sounds a little like Arnold Schwarzenegger "Get to the Chopper with your power supply"
Loved it! I only wish I could give you more than one like. Really appreciate the work you put into these detailed videos and always feel like I learned some cool electronics ideas. Keep it up!
an excellent posting. many thanks for the inspiration and taking the time out to make this!
best you get yourself a well deserved brew and chillax for a bit :)
Nice work there! I'm really looking forward to the SMPS build, since dealing with magnetics is a nightmare to me.
Brilliantly made AND explained!
Really good series of videos, and nice power supply. Great work!
When it comes to mechanical things I’ve never found anything I couldn’t fix, same as construction. I build engines, repair power equipment, boats, ATVS and maintain and repair the industrial sewing machines in my small insulation assembly shop but sadly I only have a rudimentary understanding of electronics. Wish I was smarter, I would love to try some of these projects or at least be able to repair my beloved Sony receiver that died. Still enjoy the videos though
Nice build, and look what didn't end up in a landfill!
Another great video even if I only understood half of it
I watched it but can not understand a word of German!
Great work! You explained things very clearly! Thank you!
very cool build; enjoyed watching you complete it.
as always, i enjoyed every single minute in your video. we keep learning from you mate. thanks for sharing this detailed video
Beautiful dials and test in the end
Excellent presentation, thank you.
Just rediscovered this video. It's so beautiful; simple, proven ideas from parts that we are swimming in. Sorry to necropost, just had to let you know again.
Thanks a lot for this interesting video. Looking forward for diy buck/boost variant.
Thank you very much for this circuit! It is very very stable
Very good video ! It's great when it's more than juste "how to toogle a led" !
Thank you for a very interesting and informative lesson.
I certainly appreciate this concept. Gonna build 1 4 my bench as well. Namasté.
That was so well explained I have to sub you. I was trained as an electronics technician not an engineer so your pitch is fine for the likes of me. Great work, I am inspired to try this. Thanks.
Good job, good idea to use an old audio-amp for the power supply, it helps (a very little bit) to reduce electrical waste.
I would paint the grey cover with another nice color to see this highlight on the work bench!
Fantastic channel, great videos man! keep it up!
That video was awesome, very VERY nice work.
Very well explained. I also share with you your interest of experimenting with variable power supplies. Your instruments, and neatly accommodated setup is amazing too. Congratulations! I have liked and subscribed. Your "Post Apocalyptic Inventor" is another thing I like. Best wishes from Lima, Peru.
Awesome. love the design. may try something similiar.
Really great video series this one, loved it!
Amazing build brother. Super nice!! Now to raid all my town's second hand stores for Audio amps.
only build this if the amps are dead please.
Danke, hast mir einige Ideen für mein Netzteil gegeben!
man, great video even though it was completely over my head. Guess it's time to start learning the basics.
There are more simple circuits than this that do essentially the same thing.
Great work. It's hard doing big projects. Would be great to get hold of the schema.
Nice current limiting circuit, works perfectly well indeed! :)
Thank you very much, this is on my build list ;)
Outstanding presentation, highly instructive, very clear explanation, highly enjoyable to watch.
Hervorragende Präsentation, sehr lehrreich, ganz deutliche erklärung, äußerst angenehm zu beobachten.
Really nice job.
Thank you for sharing with us....
Thank you very much for the great videos. You give me so much inspiration. Last month i picked up an Amplifier and i will give it a try to create such a power supply. Dankeschön und weiter so ;-)
I'm in the middle of exams season from my university right now but, definitely going to try a similar power supply base on this video.
Amazing, quite educational.
thank you! i really enjoyed this video
Great work
I use ordinary sized knobs on 10 turn pots... filling the holes with epoxy and then drilling it out again. ;)
:-D oh happy day! I've been waiting for a video like this from you for donkeys years. actual years too. I can't wait for the next installment in this series, the b more hardcore and explained electronics is why I watch this channel and I've missed it
As an alternative current sensor check out the Allegro ACS712 (and similar types from them). There are quite alot of them available on ebay as module and might be a replacement (with an adapted circuit) for those people who can't get their hands on the one you are using.
Great Video Thank you.
really impressive
Nice build :)
3:14 WHAT A TWIST !
Excellent!
Since the supply is regulated, you could do a "pi" network filter with a cap-choke-cap configuration to really smooth things out. The choke (inductor) has some resistance so it can make a linear supply less stable. But regulation.
Very clean power supply. Takes me back to my roots in the 60s, and 70s ham radio world. Not the most efficient. Need plenty of heat sinks depending on your load and output voltage from the transformer.
respect sir can we have for your full power supply schematic as a PDF that we can print and make power supply
Gonna be a long Friday night :)
nice job.
Great video's !!
ich wollte gerade schlafen gehen. super Video Mal wieder
Awesome work sir! Where did you get your analog panel meters from? I like them they are vintage cool!
I took the effort to really understand how this linear power supply works. This is a great idea to let the whole control circuit (with its power supply) float with the output voltage! It eases the current sensing and regulation and it makes the output voltage range independent of the supply voltage limits of the OpAmps. Only the voltage setting potentiometer is exposed to the maximum output voltage.
But there are two questions that come to my mind:
1) As the current source drives the output transistors fully "on" unless throttled by the control amplifiers - how does the circuit behave at power-on? Will it ramp up smoothly from zero or will it first output the maximum voltage until the control circuit kicks in?
2) The voltage divider ratio and with it the loop gain of the voltage control loop changes with the set output voltage. The dynamic response (e.g. on sudden load changes) of the voltage control could be quite different at different output voltages. Had this been investigated?
What I did not notice as being mentioned: the +5V of the controller power supply also acts as the reference voltage. The absolute value does not matter, the trimpots and the calibration take care of this. But it might be worthwhile to have a look at the drift properties of the +5V regulator and its effects on the stability of the overall circuit.
Great video and project!
From what i got from the vid you're using a floating output ground (Vo3) and was wondering does this induce any sort of ripple to the output (separate from the AC-DC conversion load ripple) or pose a high voltage from the output vcc to earth?
You had me at dummy load! ...ok, ok, I'm listening, I'm listening! lol
Thanks a bunch! I put together schematics. Too bad UA-cam does not allow URLs. It's on EasyEDA, search for "Analog Power Supply from TPAI". Use at your own risk as I do not guarantee the validity. Corrections would be appreciated though.
Not a complaint, but a suggestion - If you're just recording voice-overs and adding them to your videos, consider sitting underneath a tented blanket while recording. This should remove all of the large room, hard surface echo you have in your audio. You have such a rich voice, it would sound killer under a blanket. Mike Rowe (Dirty Jobs and Bering Sea Gold) does this when he films shows. They have shown him doing voice-overs while sick in a hotel room. He was sitting in a chair with the duvet over his whole body and head.
Signals Processing guy here, I can confirm that this works, great way to damp sound reflections and cleanup voice over audio on the cheap.
Yeah but if he did that he'd have to change the channel name to The Talking Blanket.
Awesome suggestion! Had never heard of this before but seems like it would work well.
I had the same thought. It'll greatly improve sound quality, the microphone seems great, but you can clearly hear the 'room'.
or you contact a produce like me , and improve the sound :) dedskin at gmail.com
Thank you for a wonderful explanation! How can I add constant voltage/constant current indicator LEDs to this schematic? Cheers!
Did you ever make a video regarding the self-designed buck converter? I think that would be good to see, especially as it crops up in your welder video too.
Sehr gutes Video! Hat mir viel weiter geholfen. Hier noch ein paar Verbesserungsvorschläge: eine Diode (1n4002) antiparrallel zum ausgang würde noch vor z.b. verpolung eines akkus am ausgang sowie vor induktiven lasten schützen. Das interne Schaltbild des TIP142 ist falsch. Die Widerstände sind anders geschaltet. Wenn sie so wären wie im Video gezeigt würde nach dem Abschalten der Versorgungsspannung des Netzteils jedes mal eine große Spannungsspitze entstehen. Am Ausgang fehlt ein Widerstand, um eine Mindestlast zu erzeugen. Wie du auch schon bei den 7X05 Reglern gesagt hast, funktioniert ein Linearer Regler nicht ohne diese. Die Dioden am Ausgang der OpAmps kann man auch durch LEDs ersetzen, um anzuzeigen ob das Gerät gerade im Strom- , oder Spannungskonstanten Modus ist. Keep up the good work :)
Piece of art, congrats!
Do you plan, at some point in time, to dive into 220V AC stabilizers ? I mean, the theory behind (like you always do) and practical DIY circuits.
I guess that are many interested in that topic, given the fact that all comercial solutions are expensive, but low quality most of the time.
Thanks in advance!
Sehr schöne Arbeit. Spricht irgendwas gegen handelsübliche Spannzangenknöpfe auf den Potiachsen?
i was quite impressed with the rock steady regulation of this regulated power supply... do you have a simpler version implemented using LM317s? I have a 5A control transformer here lying around and I want to maximize its current capacity. I was also wondering how the set current limit can be displayed without load...or offline and how I can implement a short-circuit foldback protection feature... hope you can enlighten on this
Hey, love the video. Just got a hold of a 350va transformer from a audio amplifier (48v|48v) center taps and (24v|24v) center taps. Was wondering if you could post a part list, or more detailed as built schematic? As is It isn't clear what parts/values are used in some areas.
Am I right that you could also use magnetic amplifier? e.g. a variac transformer, and an extra winding that influences the rest amount of the magnetic field for power transfer. So the small amount of current on the extra winding determines the current, and the knob on the variac determines the voltage
Thank you so much! This is exactly what I want to build in small for voltages / currents below 12V / 2A.
I had an issue there that drove me crazy, but know I have a new point to get further. Thanks!
Vielen Dank! Das ist genau das gleiche was ich in klein auch gerade bauen möchte für Spannungen / Ströme bis 12V / 2A.
Ich hatte da ein Problem, aber jetzt habe ich einen neuen Denkanstoß bekommen mit dem ich weiterkomme. Danke!
Hello I love your videos. Could you please do one on your dummy load. Thanks
German products and German engineering are always the best! You prove it!
nice video very nice design of the power supply.I've been out of the electronics industry for many years now not that I work as a mechanic.I would like to build a very good and heavy duty power supply minimum 0 to 35 volt 0 to 15 amp.I was thinking to use the 2n3055 .any help with any better suggestions would be a great help.and what would be best to control current and voltage has to be quite precise.I would appreciate if anyone can throw some hints.
Could you please do a video on the conductive strip that one usually finds behind digital displays. I have had trouble with several cheap voltmeters that lost portions of the display. I had luck cleaning the first one but the second one went completely dead after I "fixed" it. I also remember an old electronic sewing machine with a digital display I had that even when relatively new, the display segments would flicker or be absent.. microwave oven displays, too. I guess there is a basic construction common to all these devices that I am not familiar with.
Wow that was really geat explaining, Thanks.
Also if i built two completely separate circuits powered by two identical separate secondary windings. Could i wire them in series to get dual rail supply with center point or in parallel to get more current ? Basically dual channel power supply .
great video! On a completely unrelated topic, you should get a 3d printer! i think you would find it very useful and you can probably make many videos about it or just use it for your pojects for enclosures / mounts for example.
3D printers are getting silly in terms of price right now. There are good ones you can get on ebuyer and the like for £170-£300 which are pretty damn impressive.
i have gotten a wanhao i3 for 420euros almost 2 years ago and its great , same results as an ultimaker(witch costs 2000) it only prints a little slower, plus they are great for tinkering and trying out mods to improve it.
great job, in my country ; Argentia is more cheap buy that than make my self but the learn have no price !!!!!
What are appropriate values for current balancing resistors? I see you used 0.55 ohm resistors, but is there a way to calculate optimal values? I am building a linear power supply based on your great design and I am hesitant to purchase any power resistors just yet. Also, I will be powering some oscillators with this supply, and is there anything additional that could be done to prevent the power supply itself from oscillating?
Do you think that there is any advantage to tube rectified dc power supplies for audio application? I have some field coil speakers that require about 150VDC 1A. . I am currently using a PSU that uses bridge rectification. I have heard that the quality of the caps (vintage paper in oil being the best) was perhaps the only important factor. I would greatly appreciate your thoughts on this.
"Building it was extremely excruciating".
Hi i love your projects very nice keep going
I want to know how to buy from eBay the broken things may i have any link or any video please
What is the current status of the edm psu?
That's it! ...you're on the Ark!
HELLO LOOKS VERY PROMISSING THIS LINEAR PSU BUT IS THE CT OF THE AUX PSU IS CONNECTED TO THE GND OF THE MAIN PSU?