Split Rail Power Supply Kit Build - SEPIC Cuk Topology

[@GadgetUK164]

Regards SMD soldering, I tend to hold the component down with a jewlers screwdriver tip, whilst I solder one side. With good flux (like Chip qwik flux) you can do a really tidy job. But you don't have enough hands then to add solder to the iron at the same time. I tend to add the solder to the iron tip, and then the fluxed component just sucks it up when contacted - rather than using one hand to feed solder and the other to hold the iron.

[@Chickey]

I normally place solder on one pad and then heat that solder pad and place the component on with tweezers, usually it tombstones slightly as yours did but i them press gently with the tweezers and reflow the solder joint and it goes flush with the board. then i can solder on the other end of the component, works very well even on small 0805 components.

[@tengelgeer]

I almost thought I was the only one yelling at the screen @4:28 xD

[@RWoody1995]

Absolutely, especially with 0603, and its so quick because you can do one pin of all the components and just sprint through doing all the 2nd pins afterward :D

[@richiow68]

Perfectly mentioned 👍

[@chillipaste386]

Hi Julian, You are the very first one I have subscribed to on youtube as your videos are absolutely brilliant! You kicked me back into electronics a few month back with your calm and extremely good way of bringing knowledge across. Just wanted to say THANK YOU.

[@slm60uk]

When I saw this video appear I searched all your videos, convinced you had already covered this board. It wasn't until I watched it and heard you mention VoltLog I realized that is where I saw it and what made me buy it. He also makes good videos - almost as good as yours :) , and for a Romanian his English is impeccable, both grammatically and phonetically. Well worth a follow.

[@Hasitier]

I have this little supply for half a year now and it works great. I added an lm317 and a little voltmeter to the +16v rail which gives me a variable supply from about 1,25 to 14v. You cannot get a lot of current out of it but for little projects this is fine. I put all this in a project box with colored connectors for all the different voltages. And I use it often. Mostly powered from a USB charger or power bank.

[@MicraHakkinen]

14:08 about the +12 and +5V linear regulators being in parallel, perhaps this is to reduce the load on the +12V regulator. Otherwise that would have to supply all the load on the +12V rail as well as all the load on the +5V and +3V3 rails (plus losses in those regulators).

[@68MalKontent]

Bigclive's video is indeed fundamental work :) Re regulators in series vs parallel - my guess would be that usually the majority of current draw would be on the positive rails, so the +12V reg would take the sum of the currents drawn from +12V, +5V and +3.3V outputs, which might be too much for a 0.5A regulator (if I see correctly it's a 78M12). They could have added an extra 78M12 before the 78M05 to spread the dissipated power, but they didn't.

[@JohnWasser]

68Stan The Banggood ad says 300mA per channel. If the 12V regulator is only good for 500mA it certainly can't supply the 900mA needed for three channels. It wouldn't even supply 600mA to just the 5V and 3.3V channels. They would either need a 12V regulator capable of at least 900mA for all three channels or a second 12V regulator capable at least 600mA to take load off the 5V regulator.

[@DanielPace92]

Once I heard tigging, I had a feeling It was a reference to bigclive. Great classic video, indeed. xD

[@wotid]

Our SMD soldering techniques vary considerably. For once, I've bought, assembled and tested a kit before you, but I didn't document it ;) . I used a flux pen, solder paste and a hot air gun to mount all the SMD components 1st, then tackled the rest.

[@DogRox]

They're nice little kits! :-) I built three of them over the past year. I've already used one in a project. and so far I have not had any problems with any of them, even through the installation all went good.

[@Contango1000]

Kevin Darrah, I believe his name is, did a great video using solder paste and a heat gun. Haven't tried it my self, but it looked fantastic. The smd components just melted down into the paste without any tombstone effect. I think the plastic on the coils might suffer a bit from the heat, though...

[@richardboyce4921]

Another great video Julian, I personally like watching the entire kit build. I really enjoy your detailed explanations as you build and the partial build power ups. Thanks, keep them coming.

[@JulianIlett]

Thanks Richard - I'm enjoying all those facets of the kits builds too :)

[@station240]

This kit is actually in stock now on Banggood. I ordered a few to experiment with.

[@jameslmorehead]

Have you ever thought about putting up a website with a list of all the kits you've done videos on and links for purchasing? I've found it quite enjoyable to watch your videos and them put kits together myself.

[@richard7crowley]

Just what I have been looking for. I would like to mod it to produce ±15V or even ±18V (for pro audio circuits). Alas, not only is it "Under restocking. It will be available soon", but to add insult to injury: "For now, this product Does not provide circuit diagrams and installation instructions, just install correctly in accordance with the PCB screen printing, you can work without debugging". Thanks a lot, guys.

[@AdamWelchUK]

Thanks for the insight into the history, design and apparent none crediting of work that proceeded the creation of this kit. Your google fu must be much higher than mine. It hasn't escape me that you've credited everyone you could in this video - thank you very much for the mention. I'm glad to have piqued your interest :-)

[@JulianIlett]

Cheers Adam. I was all set to try and prove that the circuit doesn't work, but I felt there had to be more to it than that. If there's something I don't understand, I can't rest until I've got to the bottom of it. You did pique my interest - thanks. Yeah, the credits came along like buses in this video :)

[@SidneyCritic]

Do I sense a mod video. That would be cool.

[@linksmith1057]

There is a technique for soldering SMT parts one handed, so your free hand can (using a tool) hold down the part. Using some thick paste flux, dab some on the board pad and part you are soldering. Flow a nice blob of solder onto your iron top. Use your free hand to hold down the part, and touch the iron top and solder blob to the pad, a good pasty flux should let it flow easily.

[@kathyquinlan5922]

The problem with cascading regulators like they have on the negative rail. Is that the 7912 has to supply all the current that the 7905 draws as well as what you draw from the 7912. So it becomes a trade off between heat-sinking of regulators (the way it is done on the positive rail) and the limited output current of cascading in the negative rail (you can not expect to draw 1A from both the -5 and -12V rails)

[@Bits32]

Your analysis part of the video is brilliant. Kudos.

[@brit1066]

Another great video, well researched electrical theory as well as practical information on the actual construction.

[@ericseyden6635]

Now I know why I didn't get any negative voltage out of my build. Thank you!

[@GadgetUK164]

I would be tempted to feed the output of the 12v regulator into the 7805 rather than the 16v - well spotted! Maybe they did that so the 12v rail could provide more current, but I would think that the 7805 wouldn't draw much current unless the 5v rail was loaded?

[@williamsquires3070]

You could always cut the trace on the input pin of the 7805 and solder a bodge wire from the (now isolated) input pin, to the output of the 7812. :)

[@zx8401ztv]

Nice little kit julian, i like the use of blu tac, stop the little devils moving :-D. Your 5v regulator input does seem a better way, but the 12v regulator would be loaded up perhaps double the current, perhaps a bigger 78xx regulator with heatsink would be needed. Or put a big zenner in series with the 7805 input to drop the voltage a bit. Possibly put a 2v zenna across the input led to stop it getting really bright :-D

[@sparkyprojects]

Maybe they put the +5 on the main rail because it also drives the 3.4v regulator, having 3 regs in series may be as bad as driving the +5 direct, 3.3v reg may have a lower max input. If you're using it for audio, i would increase the size of the smoothing caps, though you could include extra caps on the audio board

[@willynebula6193]

Sparky Projects was thinking the same thing. Also maby the 5v reg can supply more current

[@ianide2480]

Try soldering a tad bit of solder to 1 pad first (use flux). Then use tweezers to hold the part and then heat the pre-soldered pad with the part held in place and pressing the part into place with light pressure.

[@paulsengupta971]

Could you use a crocodile clip to hold the surface components down when you solder them? At least the ones near the edge. I was going to ask this last time you were doing surface mount but I saw lots of people pointed you to surface mount videos! You could also use one of those plastic B&Q (or pound shop) clamps as long as you didn't get the component too hot.

[@revmpandora]

when you first said 'tigging', I immediately thought of Bigclive; sure enough, you mentioned him moments later. funny stuff!

[@zylark3726]

Ever considered to 'invest' in a proper Solder Station? From our Banggood friends, you can get a very good Hakko 936 clone and a great variety soldering tips for a very reasonable price. I got one, and could not be more pleased with it.

[@LouesSCat]

Your timing is interesting... I have been looking for a means of generating 12v, 5v and 3v outputs >.> I settling on boost the input to 12v, then use a switch mode regulator to bring that down to 5v then linear regulate the 5v down to 3.3v from there. Since there was low demand for 3.3v, moderate demand for 5v and high demand on the 12v rail this seemed to work out reasonably well >.> Mostly the reason I was doing this was because that is what I had the parts to accomplish ^.^; Doesn't half chew threw batteries though .>

[@proyectosledar]

I really like that kit!!!

[@Zadster]

Should you feel the need, for op-amp work, you could probably change the feedback divider ratio on R2/R3 and raise the output to 18V or so, following it with +/-15V linear regulators.

[@JulianIlett]

I've got another one coming which has +/- 15V :)

[@Zadster]

Excellent, it will be interesting to see what the differences are and how it performs.

[@jezjoseph9461]

i always apply solder to a single pad and then with the component in tweezers you can slide the component into molten solder by applying the iron again .

[@deangreenhough3479]

great explanation, great post as always

[@raymondheath7668]

That would be perfect for the DDS signal source I put together last year which uses all those voltages. I ended up building a transformer driven linear PS

[@JulianIlett]

I think that's why Banggood sell it - as a power supply for the Hiland DDS.

[@SpeccyMan]

It's also been used to replace the dodgy PSU in the FeelTech DDS. I have one of those and will be making the mod some time in the future.

[@MarcelOoms]

Opamps hate HF noise, so a scope of the ouput voltage noise would be interesting! Unfortunately almost all linear regulators are not good in surpressing high frequency noise. Below 1K they can reject almost 80dB of the supply noise, but at the much higer switching frequency this drops below 20 dB! So the noisewill mostly depend on the quality of the low pass filters in the output.

[@TheFunkman]

As usual I love your videos. well, most of them. Good for you again!

[@Wasserverschmutzung]

Great video! I'm really looking forward to see the comparison of output noise between first stage and after linear regulator.

[@DasAntiNaziBroetchen]

Nice name and avatar.

[@MrBrymstond]

I think I'm going to get this if you don't have issues like all the parts, good luck.

[@iceberg789]

i wonder if this topology will work with toroid cores. having open core inductors close enough, probably couples them lightly through air or something ? and yah, having linears in series makes the 7812 hot, while parallel makes the 7805 hot..... either way something will always get hot i guess.

[@booboyBL]

I seem to remember from a previous video that you already had one of these, Julian. IIRC, you got it to power a DDS signal generator kit. I have both of those kits.

[@JulianIlett]

Yeah, I have the DDS kit as well - that'll get built at some point.

[@JUSTGOMAKEIT]

could you explain the whole negative voltage thing. i cant get my head wrapped around it for some reason. and what is it used for?

[@JulianIlett]

I'll explain all that in my next LM3915 video

[@chartle1]

Would a chisel tip help. Somewhere someone, maybe Lady Ada, said fine point tips should only be used in very special situations.

[@russ18uk]

Think that was Dave. He hates them. I used to find soldering hard until I stopped using conical tips.

[@Leonelf0]

Cliff Hartle yeah, conical tips have minimal surface area for heat conduction, so they tend to take long to melt solder and sometimes freeze to it...

[@chartle1]

Yea and for some reason that's the tip I'm using right now. Got to swap it out.

[@NeuronalAxon]

So what shapes of tip are the best for general purpose, average-case use? 'Chisel'-style tips - is that it? Any other good shapes? What is the special use case of the conical ones? Just to get into really awkward places? It seems that 'they' always provide the worst shaped-tips with most soldering iron kits. I always check that replacement tips are readily and cheaply available when I look at irons - Maplin (in the UK) have been guilty of selling mid-range irons but not the tips(!).

[@Leonelf0]

Chisel is always pretty good. Conicals are just pretty cheap, so they provide them with everything... If you're into SMD you might want a hoof-style tip, it has a reservoir for solder, you can just drag it over a strip of pins and they'll get soldered.

[@smithjonathan]

Love your channel. I’ve learned a lot (mostly that I can sit and watch someone opening their mail for hours). I have an old(ish) 19.5 laptop power supply. If I lop off the plug and solder on a suitable plug, can I use it with this board to get a more useful power supply?

[@john-r-edge]

This board has surface mounted components which are harder to solder than when the board is drilled. In that case the component leads go through the holes, and the soldering is done on the opposite side. That is easier to do. So what is the advantage of taking the surface mount route?

[@chrisallan4717]

A comparison between coupled and non coupled inductors in a SEPIC convertor: www.ti.com/general/docs/lit/getliterature.tsp?baseLiteratureNumber=slyt411 It seems the coupled version is preferred because there is less chance of unwanted resonance and the coupled inductors are two coils on one core with the same footprint as one inductor, so less space taken up.

[@JasonDukeSEO]

Clive's seminal work? Surely fanny flambeaux was the pinnacle :)

[@MobiusHorizons]

yes, but i don't believe he has the rights to that any more.

[@JasonDukeSEO]

unfortunately you're right.... However...they make cunningly nick the video, but they'll never take "our Clive" :)

[@alanpowell328]

Julian, I reckon the positive side will generally need supply more current, particularly at +5 volts - that is certainly the case with PC PSU. With the +5 volt regulator feeding off the +12 volt regulator, you could easily exceed the current capability of the +12 volt regulator. Just a guess - i have no idea what the specs of the regulators are. Alan

[@cambridgemart2075]

That's exactly my thoughts as well.

[@JulianIlett]

Yeah, I do see what you're saying. If you pulled the full 500mA from the 5V reg, you couldn't pull any additional current from the 12V reg (if they were cascaded).

[@superdau]

Oh, I'm late to the party. Just spotted the 100k torch ;) . I haven't yet watched 2 or 3 of your previous (slight backlog ;) I have to catch up on the weekend), but from the thumbnail it looks like this isn't the first video with them. Congratulations!

[@JulianIlett]

Thanks Superdau - there was a big spike in new subscribers from the Big Clive collaboration :)

[@paulsengupta971]

Who wouldn't want to win a Big Clive classic LED panel? :-)

[@OffGridAussiePrepper]

Pitty I can't use this to run my HTPC from my 24v bank which can max out up to 30volts when charging in equalizer mode.... What r ur thoughts?? is there a kit u know of that I can get for a decent price??

[@WaltonPete]

Just exactly how would one go about 'lightly coupling' ones inductors?

[@juliusvalentinas]

Is there linear constant current like this?

[@Brainstorm4300]

I'm still not 100% on all these switch mode topologies. I should stop being lazy and pick up a book or two. Any recommendations for a good read?

[@robh1908]

You're a bad boy Julian, what happened to part #2 of this build?

[@JulianIlett]

The remainder of the build was just voltage regulators. I did show it working in my LM3915 follow up though.

[@robh1908]

Yes I saw that :) I just like to see builds completed. Keep the the excellent videos. I feel like a child at Christmas when I see a new video notification from you.

[@jeffmerlin2580]

Thanks! Any change of getting an op-amp tutorial?

[@JulianIlett]

Yes, now I can build op-amp circuits without the hassle of big battery packs. More on op-amps to come :)

[@jeffmerlin2580]

That would be great! Back in the 80's I had a decent knowledge about op-amps, but that's 30 years ago...

[@johnarmstrong3782]

Thanks for doing this. Ordered one already to power the wave generator kit. Still don't know what -12 is?

[@webchimp]

Watched another video recently about putting a different power supply together with + & - outputs, and it helped me understand. Basically if you put two parallel diodes on an AC output, one reversed, you get the top half of the sine wave out of one and the bottom half out of the other. Then you can then smooth this to get + & - DC out. I think that's how it worked.

[@johnarmstrong3782]

webchimp Thanks for your reply. I sort of understand although won't this power supply produce a straight line signal rather than half a sine wave. Anyway, unbelievably the kit came in the post the same day and I've built it and it does what it says on the tin!

[@ФилиппХардкоров]

Hi guys. Help me to understand. Is it possible to use a resistor of 10k instead of a 12k resistor

[@jcwadkins2100]

using a new dmm? how do you like it ?

[@tm80notgoodwithnames58]

I have learned that you should not "pour water" on to the sponge, rather just wet it and press all water out of it as you can, the water is only to make that sponge not burn.

[@bokkenka]

Why do you have holes in the sponges?

[@TheFunkman]

For the smt stuff; just invest in some solder paste.

[@krishna34674]

I found this supply doesn't like starting up under loads over 100ma and the xl6008 gets to like 100*c under loads over 200ma

[@Space_Reptile]

how much amps can you pull on each rail?

[@Totogita]

Hi Julian. I have a question about the maximum current that this supplies on the 5 volts rail. I am trying to power a raspberry pi3 with some 18650

[@MrOpenGL]

78M05 maximum current: 500mA. It won't be enough to power a Pi3 which needs a minimum of 750mA to be stable. Besides, you'd better getting a cheap empty powerbank on Ebay and then putting your 18650s in that powerbank. This board is meant for very low current devices like preamps or oscilloscopes, not for powering heavy loads. The linear regulators on the output will get very hot: at 500mA of load, you are dissipating 5.5W of heat which is wasted!

[@Totogita]

MrOpenGL thanks

[@petehiggins33]

This is really adventurous of you Julian, I designed switch mode converters for a living before I retired and I never understood either SEPIC nor Cuk converters well enough to actually use one. One can get the basic principle of how they transfer energy from the input to the output easily enough but understanding the details well enough to design a converter is a step too far. Most converters like this rely on using the inductors in continuous mode ie the load current should never be less than the ripple current in the inductor so they can't be relied on to work properly at no load. Cuk and Middlebrook are well known in the industry for for inventing new complicated converter topologies which involve lots of complicated mathematics to understand and use.

[@MrBrymstond]

Flux it all, I love the way it flows...

[@slap_my_hand]

another kit?

[@TheDutyPaid]

Are the bands on your torch new?

[@JulianIlett]

This is the 3rd video with them :)

[@TheDutyPaid]

Just remembered your reply from a week ago "Loom bands at the ready ;)"

[@JulianIlett]

:)

[@simonhopkins3867]

+ and - V outputs is this going into the vocoder?

[@JulianIlett]

Probably not the finished vocoder because I think more current will be needed, but for testing parts of the system.

[@tonalaxis]

Do you think this would run a few Eurorack synth modules??

[@chrisallan4717]

My thoughts too. Plus a nice +5v supply as well. The power is enough for a few modules, the test will be how much noise is created by this circuit. I've ordered two from Aliexpress and will be testing them for noise in audio applications.

[@tonalaxis]

Chris Allan it would be a good cheap solution for a few modules yes. Wonder how many amps it puts out?

[@chrisallan4717]

I built 2 and had problems with both. The 12v regulators seemed to drop the voltage to 4.8v. Tried a beefier psu than USB and the dc-dc chip fried. Same issue on 2nd board, not getting +/- 12v

[@mangyshlakdapaul]

this is strange Chris. I also think about getting one to test modules or schematics

[@ArcAiN6]

I'm quite disappointed we didn't get a reappearance of the finger puppets. Ah well, at least we covered a relatively new design feature. :) Cheers

[@MartinParryBoyGenius]

Sorry if this is a dumb question... Since you were getting > 16v before the linear regulators, so could I swap the 7812/7912 for 7815/7915 and get +-15v ?

[@JulianIlett]

Not a good idea. The 7815 has a typical dropout voltage of 2V (according to the data sheet).

[@MartinParryBoyGenius]

So it does. Thanks for the quick answer. I'm very much enjoying your channel; keep up the good work.

[@himselfe]

I've always been somewhat mystified by negative voltage rails. I understand that a negative rail is one where the voltage is at a lower potential to ground, but does that essentially mean that the polarity is reversed (i.e the same as flipping a battery around)? In which case, what purpose does this serve in applications that aren't things like motors?

[@himselfe]

Just to add, I've done some googling and I think I understand, in that it's the same as setting your ground point as being the mid point between two batteries in series, and this has applications for things like audio where the signal is basically AC? Would be nice to see some sort of explanation of this in a future video for noobs like me though!

[@Coolkeys2009]

Lots of analogue circuits require negative rails, if you picture a sine wave it swings positive and negative. Many Op amps require negative and positive supplies even if the output is only positive :-) Hifi pre and, power amplifiers and audio mixers are another example, I have and old computer sound card that has several +/- rails for op amps and A/D converter, also digital music synthesizers samplers etc.

[@sardaclan1]

your RYOBI multimeter? are you happy with it? there is a local pawn shop that has the same unit new with the film still on the display and spare battery and charger for $40.00

[@JulianIlett]

It's probably only worth that if you already have other tools in the Tek4 series

[@sardaclan1]

i dont. but i dont think that unit was offered in the states. i cant find much info on it. it looks to be a rugged unit and i tend to be unusually hard on my meters...i actually drove over my last good one.. thanks

[@TheProCactus]

Yes, now I need a chook sandwich.

[@_who_cares_1123]

Hi Julian, I have a question. Do you leave you Solar Batteries out all the winter? Isnt that bad for the batteries?

[@JulianIlett]

Interestingly, discharged lead-acid batteries contain mostly water which will freeze not far below zero degrees. A fully charged battery won't freeze unless it's well below freezing.

[@_who_cares_1123]

Julian Ilett Thanks. Good to know. I think i'll put my System up tomorrow :D

[@SquireDAF]

Remember they are the same or are car batteries, and they do well enough outside

[@therealmeisl5609]

Finally, TIG-soddering is taking over!

[@tOSdude]

*notices the multimeter during the explanation* Uh, buddy? What, perchance, is that thing doing? And should I be worried?

[@davestech6357]

Why wouldn't you instead make this an adjustable tracking regulator? All you would need is to add a pot instead on the ref pin voltage divider. It would be be more versatile and you could still use the other regulators as well when it is above the fixed regulator voltages.

[@eurobum2012]

Another way to solder those inductors would be to put a dab of solder paste and tossing it into an oven.

[@whatthefunction9140]

is blu tack reusable? we dont use it in the US.

[@JulianIlett]

Yes. It gets dirty over time, but you can pull it apart a few times to restore it

[@thatsunpossible312]

In the US it is often white and sold as "Tac n' Stik" (Elmers), "Fun Tak" (Loctite), or simply generically as poster putty by everyone else. You can get it at Target, Walmart, Home Depot, etc.

[@tubical71]

Hmm i think you should do your assemblings/component solder job in a time lapse....i just watched the very last minutes..the other is just too long/boring to watch...and may focus on where the "rubber meets the road" and test this thing. Also there´s a reason for not putting the positive reggulators in series: when you draw about 800mA on the +5Volt rail and these 78xx would be in series, there would be likely no chance to draw some current on the 12Volts rail anymore, as the 7812 would be near its maximum current already. therefore, if you want to use both and load both with some serious current going parallel is the only solution.

[@AgentOffice]

so can you get 24v?

[@Jonas_Meyer]

Yes you should be able to get 24V but then i think you cant use 5V or 3V3 with the same ground.

[@kirkb4989]

Yay- Bigclive "TIG-ing" reference!!

[@kirkb4989]

BTW: You use a BigClive TIG-ing motion to properly use your metal sponge tip cleaner!

[@Ncky]

I love how people pronounce Slobodan Cuk in English :)

[@JulianIlett]

Did I get it wrong?

[@Ncky]

No, it's good :D

[@MrBrymstond]

This guy I watch does a lot of retro music and cameras called Techmoan and he was making fun of American English and he was installing the tubes in a preamp and called them chubes, chubes? I said hey wait a minute so the t in tubes is silent and you use ch to pronounce it? He said not really, it's just the way we say it... lol

[@MrBrymstond]

If we can't laugh at ourselves, we're really screwed! {=D

[@Ncky]

sometimes you get bored of yours own language

[@cryptoponics]

I have a question for the community. I am a cryptocurrency miner and have needs for this exact same thing but in a +/-150W range. Does such a thing exist? This one from what I see is 10W maximum. Is it as 'simple' as taking the schematic and scaling up the electronic components? What might be a 'rough' cost of such an animal? Any help is greatly appreciated and thx in advance

[@PeranMe]

"[Big Clive's] seminal work" :-)

[@AntonyCartwright]

Thanks very much to 7?!?! What is 7?

[@richardrudek01]

Jeri Ryan, obviously... :)

[@alloutsavage7110]

3:06 rogue capacitor OW GOD

[@KnaufL]

last time i was this early was last time

[@Anvilshock]

3:06 - That would be a stray capacitance.

[@just5444]

electrons are attacking your multimeter 😂

[@enginstud8852]

Not putting linear regulators in series gives better current capabilities

[@jacko404]

Hey Guys! Make sure you dont cook this thing. use low temp solder on the regs.

[@nickpelov]

78/79 series regultors are too slow to reduce the high frequency noise. LDOs do better job. That'ss why you'll see this parameter in LDO datasheets. however above 10-20kHz the noise rejection is not that great. My guess is that this power supply will be terrible for audio.

[@InssiAjaton]

If my memory serves me, the Sepic inverter provides quite low noise. There are the multi phase devices that may be better, but at some point an optimum choice is something that is Simple and Good Enough.

[@SatyajitRoy2048]

The +5V is taken separately because probably the ±12V will be used by analog circuitry and this 5V for some digital stuffs. So to keep the digital noise out from the analog path, the designer has cleverly designed it for a purpose. -5V could be used just for biasing or whatever, but certainly not by any digital system unless there is a specific need for it. as you have all the gears to test and verify things, I just cant imagine why you spend most of the time capturing video of your soldering and variety of sponges you use one after another. You could have easily managed made your video with a bit of quality showing the performance or load testing and even ripple on those output voltages. Yes, a video on good quality soldering practices is very much informative, but then video title has to be made likewise. Its not even a fully product built showcase, and if this small thing goes more than one episode, then how long will it take to PIC assembly programming. My guess is more than year to configure all the peripherals of 8 pin PIC MCU.

[@ufohunter3688]

I came across the schematic of this kit while researching a replacement power supply for a Feeltech FY3224S signal generator. Hope it helps some one. forum.banggood.com/forum-topic-123630.html?page=3 If the link doesn't work, it might have been moved to another page of the forum.

[@richardgrier4721]

The power dissipated by the +12 regulator would increase (quite a lot), if the +5V regulator input was to be furnished from it. The net power dissipation in the positive regulators would increase and the efficiency would decrease. This would be an inferior design.

[@fredblogs7819]

You need a better soldering iron. Try making one of these kits, www.banggood.com/Digital-Soldering-Iron-Station-Temperature-Controller-Kits-for-HAKKO-T12-Handle-p-993248.html - although you'll need a more useable shaped tip to go with it.

[@MobiusHorizons]

I have just built one (video this weekend), and am very pleased with it. The thermal capacity is certainly impressive coming from one of the 936 clones.

[@webchimp]

Oooh, it's got a Three Heart Aviation Unit.

[@station240]

Circuit diagram is here forum.banggood.com/forum-topic-123630.html?page=3