Warning: ⚠ ⚠ ⚠ have fun but always remember to be Safe, anything you try is at your own Risk , thank you

These small switchers are invariably flyback types. Significantly raising the output voltage of the supply MAY result in damage to the switch on the high-voltage side. If you are using an AC line voltage well below the allowed maximum you are probably safe. If your line voltage is already near the maximum allowed, you could destroy the switcher. The secondary voltage is "reflected" back to the input side and "stacked" on the supply voltage according to the turns ratio of the so-called transformer when the switch turns off and the energy stored in the input winding is being transferred to the output winding. This is the only time that the inductor really acts as a transformer, and it is a design limitation for a flyback converter. Typically the inductor is designed so there is some safety margin between the sum of the peak DC on the input side and the reflected output voltage and the voltage rating of the switch. If you increase the output voltage it may result in exceeding the maximum allowable voltage across the switch which usually causes it to fail short-circuit. Another potential problem is that many of these switchers use an extra winding on the inductor to power the switcher IC after it initially starts. If the output voltage is set too low the IC may get insufficient voltage to keep it running, resulting in in shutting down, trying to restart, running for a fraction of a second (typically) then shutting down again.

It will work in low current range (ae no load), because voltage output element is transformer, that zener only for voltage stabilization via feedback circuit.

An excellent and necessary device, thank you!!!

I have analog version made from little tranformer 30V 150mA with current limiter at few mA so i can check the Zener diodes values up to 30V.....but this is AWESOME idea as well...very compact!!! Will do some of this as well for sure!!!

Very useful to discover the power of any components.

Thanks to the clear and concise way you explain it makes one want to go do it right now

Thank you for the useful information, you explained it clearly and made it easy to understand! 👌🏻

Nice! Looks similar to the TV backlight tester device.

Thanks to you, I can evaluate our old chargers, thank you very much...

THAT WAS BEAUTIFUL ! I tried to take an electronics course at a local high school tech night-school, but there weren't but 5 in my class. I was 15 and tge average age was 25 to 40. They cancelled our class & gave us the choice of getting our tuition back or choose another class. I went to MACHINE SHOP. What you did I followed, but didn't understand the WHY's and Where-fores. I understand, pretty much, what each thing does, kind-of, but not together. Please do a video on HOW components do the outcome, together. My expertise was rewires and burn-ups on Locomotives. I let somebody else take care of the solid state stuff. Thanks again fir your content. It was very well done! I'm fixing to SUB.

Thank you very much for this very useful device. In my opinion because of the voltmeter power supply is maximum 30 Volts, you don't want to excess 29 Volts. If it is possible to increase the output voltage more than 30 Volts, you can add for example 7812 voltage adjusting device and take + 12 Volts for power supply of voltmeter. Thanks again. 👍

if you just turn the pot around, you would get increasing voltage with clockwise rotation....

Fantástico! Indispensável na bancada de qualquer profissional da área da eletrônica. Parabéns e obrigado por compartilhar. Um respeito abraço do Brasil 🤗 🇧🇷🙏

WOW!!! Thank you so much for sharing your tips and tricks with all of us and I’m very impressed 😊

Bruh, I've got to say this has been one of the best demonstrations on how to desolder components from a PCB. I WILL be referencing this in the future when I move and have time to get into electronics again...

Very good information, earlier i show one circuit with multimeter after adding some circuit we able to measure led, zener diode , mcpc ect, and there voltage.

Saludos desde Medellin muchas gracias por compartirnos tus grandiosas investigaciones

Well at least it's not as deadly as some - but i'd still look at that transformer closer before using it. Also most phone chargers will have a '431 reference of their own, so modifications are either easier or harder, depending on the circuit... Finally, you should never push a transformer winding too far outside it's design voltage, as things get quite inefficient - possibly even dangerous! There is a reason why a relay clicks in the benchtop power supply; it selects three taps on the secondary winding - 0-7V, 7-15V and the final one goes to 30V... Simply looking at transformer action etc. should make it clear as to why it does this (hint: it's to do with 3Amp output current) Here there is a 10K? resistor, to limit the current - so the power handling is actually not bad...

So nice to see a fellow who actually knows how to solder!

Grand idea and useful point. I at first thought you were going to just make a adjustable power supply, but what you made was very good a testing device for Zener diode mostly or LED diode power value. I am still shocked to see the original power adapter have the possibility of 30 volts. I'm assuming that phone charger is a 5-6 volt power adapter, so that Zener diode had a lot of blocking to do. It is no shock these can still overheat. That voltage drop energy has to go somewhere....

Depending on voltage drop in wattage is how much heat your have to absorb

I just did this, was testing a smd LED, touched the uninsulated connections to the power supply inlet with my elbow…. Muscle spasmes and my arm shot out…. Punched the cat….. cat went out the window…. Landed on my old school teachers head….she fell over onto my car and broke my door mirror! Thanks! Now I have no door mirror and a vets bill for a cats PTSD fear of heights and a school teacher that now gives my kids bad reports at school parents evenings! All for saving a couple dollars on a ready made unit!

Excelente video. Sus videos son muy útiles.

here multimeters are cheap at harbor freight, etc. Does this do something a regular multimeter can not? It might be more useful to use a case mountable potentiometer that can be easily adjusted and make this into a variable power supply. you could use this voltage display or use a voltmeter ammeter display.

I am industrial technician, repairing and installing freeze and cold systems. I´m not into electronics repair, but that looks great tool for you guys. I saw the complete video, very interesting. Thanks for uploading clear and good quality explaining. Best,

Do the component values change for 120VAC? I noticed that the unit had a European plug so was probably running on 220VAC @ 50Hz.

Muy buen video y excelente explicacion. Muchas Gracias.

Good job, Thanks a lot.

Sir please make a video about auto on off timer circuit for any project.

crt tv fly back nosel which is having high heat resistance, cut the half inch straight part and push on soldering sucker that work well and this way sucker white plastic tip will not damage the pcb. Please make a short vlog on this.

Very wonderful idea

this is zener diode checker and tester.. briliant...

Rapaz, muito bom mesmo. Simples mas eficaz. Parabéns pela excelente ideia. DEUS continue te abençoando.

Earned a sub. Great content!

I own an UT33C since 2016.

Hi, I never through old electronic stuff and it very often find its use, even just for study of their design and not only electric parts ... Regards Jean-François

Acho sensacional esse tipo de recurso eletrônico para recuperar aquilo que está danificado e até melhorar o seu funcionamento. A eletrônica sempre me fascinou desde de criança. Meu pai estudava eletrônica via correios e chegou a montar um rádio. Enfim, o video foi muito interessante.

essa pecinha azul serve para aumentar e diminuir a voltagem? por que tem um no AVR do meu gerador e eu aumentei e vi que mesmo ele em marcha lenta a energia ficou mais forte, só que não sei se isso pode estragar ele.

Interesting, but I would have picked a better charger to modify. That's one of those dangerous Chinese suicide chargers that doesn't even have a fuse or interference filter, and if CY1 is really a Y-rated capacitor and not just a 1KV cap I'd be surprised. I don't even like having those things around.

Ferramenta excelente!

It's amazing! Thanks a lot!

Adoro eletrônica parabenizo vc por compartilhar seus conhecimentos 👍

*Не стоит забывать о том , что не смотря на изменение выходного U , выходная P (мощность) = остаётся прежней* ☝

great idea, but LEDs are current sensitive it means that if more current is passed than what a led is designed for , it may cause burning. most of 5mm LEDs requires about 20mA to work properly. so how output current is controlled!!

This is a super cool device that I would have had use for recently! Instead, I took LEDs of differing voltage ratings and a whole bunch of resistors to make them equal brightness. Question: how can this circuit measure the "voltage" of an LED, which obviously can be safely run at different voltages? How does it find the nominal or ideal voltage?

i advice you to use a piece of silicon cable isolator for your soldering pump's end pipe. it's original part is normally too rigid plastic and you can buy a lastic cover but they are expensive, whereas 2-3 cm silicon cable cover is almost free and more useful than original one.

Neat little project. :) The video is easy to watch and listen to. It was good to clearly see how to desolder; I haven't had enough practice at that.

Grazie! Molto utile per scoprire la tensione di qualsiasi LED.

I like how you explain what the name and number of the part your using

Muito bom. Assim que eu tiver o voltímetro e o resistor variável, vou tentar fazer, um pois é muito útil. Saudações do Brasil.

it is quite dangerous to OVERCLOCK the fly power supply at 6 V to 30 V with such a power, the reverse voltage on the output diode will grow (up to 250-300v) and it needs to be changed! but what is much more dangerous is the gratifying voltage on the 1 winding and the corresponding impuls on the MOSFET DRAIN inside the PWM CHIP! if it exceeds the limit for them (and this is very likely), then there will be a big EXPLOSION and possibly a fire! but the idea itself is of course interesting, just for the correct and safe release of it, you need to recalculate and rewind the transformer for your new voltage and replace the diode with a corresponding voltage 400-800v ulta fast diode!!!

Awesome! Thanks!

Thank you sir! very amazing! But what happened to LED?

I have a question? Can it modified to use the Multimeter, We will not be spending on extra Voltmeter and Probe and if Yes. Please share the modified schematic. Eu tenho uma pergunta? Pode ser modificado para usar o multímetro, não gastaremos com voltímetro e sonda extras e se sim. Por favor, compartilhe o esquema modificado.

That 470 uF 16v cap dies anyway on these units anyway. Even without the mod it’s a good idea to replace it.

Nice trick, don’t forget to change the output capacitor to one with 30v or over

Forgive my ignorance, but what's the use of the pot if it's to be set to its highest value? Wouldn't be more convenient to use a resistor, was it 500K?

would this work with a 2 wire (red/black) voltmeter? and how would you alter the circuit in that case?

Thanks for tutorial yhanks for sharing.. 👍

Don't mess around with high voltage ⚡

Wow it's so awesome. Really I fulfill my all requirement from this project. Thanks to share this knowledgeable video for us. "The Technical Learner" ( Mr.Chandrakant.S, From India.)

Ferramenta incrível. Vou fazer uma tbm. Obrigado

Is it possible to make a power supply 5V 1.5A with this modification if I have a 2A charger ??

Exposed wires carrying mains voltage is very unsafe. To everybody who are reading this comment, please be careful of the high voltage and insulate it to reduce chances of getting electrocuted. Everything you do with electricity is at your own risk. Thank you 🙏

I wonder how many times you got shocked by the mains during making this.

Супер ))) Отличная приспособа получилась !!!

Hi What are the specs of the phone charger you used to build this?

That is nice soldering !

nice, but why don't you show the schematics of this diode-replacement (potentiometer circuit) at 2:33 ?

Well done!

如果一些不常用设备具有一个相通的接口，用它做电源也可以，最好有几个固定档，这样会延长电位器的使用寿命

First video I watch... I already like you. Subscribed!

how to blow up on board capacitor 101. MAKE SURE YOU REPLACE THE CAPACITOR TO THE HIGHEST RATING ON OUTPUT!

And the fact that the PWM controller will be powered by more than 6 times the increased voltage does not matter?

Great video thanks! Please can you tell me what model of mobile phone charger was used? My old ones have different PCBs internally...

Здравствуйте.Лазерные диоды с cd rw или другие лазеры, проверяет? Вы, можете дать ответ?

I built one, it works well, thank you.

Please make a video with the installation of components in which a 110v power supply will be used

Great except phone chargers aren't analogue devices any more, they all have logic in them that negotiates current and voltage with the device you connect them to.

Ah, recreating the buck step down/step up converter. except with those you can independently adjust current and voltage.

Thank you for sharing this video. 👍 👍 👍

Super job

Excellent work. Great explanation.

Всё! У забытых зарядок начнётся новая жизнь :)

Muito útil o equipamento que construiu! Desejo-lhe sucesso na vida e sucesso profissional.

Pregunta este proyecto lo puedo utilizar para el funciomiento de un taladro que consume 18 v.? Muchas gracias desde Cartagena Colombia y muchas bendiciones

Gostei muito do projeto, só tenho uma, a fonte utilizada foi de 6v 1A,mas esse projeto eu posso utilizar em outras fontes como de 5v, por que é a fonte mais utilizada nos dias de hoje, ou eu tenho que utilizar o mais próximo do seu projeto, porque eu gostei muito e doido para fazer. Obrigado por divulgar o seu ótimo trabalho.

can we use lower voltage and amperage adapter? like old nokia charger voltage around 5v and current around 800mA?

I AGREE,I HAVE WORLD CLASS COLLECTION. SO MANy INTERESTING USES!

I like the GND and the kiloohm.

Great video waiting for more

Не плохо вы очень просто придумали, как проверять светодиоды сколь они употребляют напряжения, с уважением Евгений. 💯👍

ahirnya ketemu juga tutorial yg saya cari cari terima kasih boss 👍 sukses buat anda 🙏

You are a wizard! that was nice to watch, what a cool useful tool. Thanks for sharing. I've subscribed. However mains and hobbies might go boom!

Solche Netzteile können Tödlich werden,wenn es einen Durchschlag der Netzspannung zur Niedervoltseite gibt.Ein Trafo ist 1000 Mal besser.

Did you just plug into mains voltage to fiddle with it?

"Watch to the end". Okay then. Start watching at 5:10. There a idea of construction: Zener diode tester, with 10k series rezistor to DC 30V modified adapter output. Scheme of TL431 mod: 1:20

Did you solder anything in place of the led?

I love it and I want to try but I want to use DIGITAL VOLT METER with AMP. how can I conect?