What is the best Reverse Voltage Protection Circuit? || Repairing a Lab Bench Power Supply

Поділитися
Вставка
  • Опубліковано 4 лют 2025

КОМЕНТАРІ • 945

  • @ElectroBOOM
    @ElectroBOOM 6 років тому +2535

    I feel ... included! :D

    • @RustieShackleFord
      @RustieShackleFord 6 років тому +110

      ElectroBOOM where them free oscilloscopes at 👀

    • @Guilherme_Parreira
      @Guilherme_Parreira 6 років тому +136

      ElectroBOOM FUUULLLLBRIIIDGEEEETEKKTIFAIAAAAA

    • @tesseract342
      @tesseract342 6 років тому +23

      so few seem to have seen this comment

    • @johndah4x0r21
      @johndah4x0r21 6 років тому +40

      Vodka + The smartest EE (electrical engineer) = *Bang!* [F--k! Sh--! What is this!? Ahh-F--k!]

    • @BadMax02_VR
      @BadMax02_VR 6 років тому +8

      so few saw it because the video was posted yesterday and only today he wrote a comment when the majority of the active subscribers have already watched the video

  • @Kalvinjj
    @Kalvinjj 4 роки тому +126

    That power supply has the weirdest heatsink I've ever seen and I love it

    • @GrafRucola
      @GrafRucola 4 роки тому +5

      It’s so cool!
      BTW it’s common in other ELV LabPSUs as well :)

    • @bretsutherlandsterriblemem8439
      @bretsutherlandsterriblemem8439 4 роки тому

      Xbox One heatsinks are kinda strange too lol

    • @daleburrell6273
      @daleburrell6273 4 роки тому

      @@bretsutherlandsterriblemem8439 YOU BETCHER LIFESAVERS-!!!

    • @ejezragaming2187
      @ejezragaming2187 3 роки тому +1

      Maybe the power supply gets hot quickly. So the big heat sink is used to make it cool. Why am I so nerd😂

    • @mikeguy1899
      @mikeguy1899 3 роки тому +3

      @@ejezragaming2187 very clever observation

  • @ahndeux
    @ahndeux 3 роки тому +26

    Scott always impresses me with his soldering skills. Amazing as always.

  • @klong4128
    @klong4128 4 роки тому +2

    Very good scott ! I recalled 10 years ago when I taught industrial technicians/engineers ElectroPneumatics .The new laymen/greenHorn always causing 24v 10A power supply burnt. When I open out the CE or Industrial Professional power supply : The fast blown fuse never burn but others components burnt. Later I change the Fastest-fuse.Yet the same history happening .The last resort are buying two diodes lm4002. Same situation occuring.Finally I had to use lm4007 diodes, each connected inseries with + terminal and -terminal respectively. Good luck ,for more than ten years nothing Power Supply will ever burnt occuring !

  • @nautitard
    @nautitard 6 років тому +6

    I see it was an easy repair this time, but I would love to see you reverse engineer things and general repair tips and tricks. Maybe this isn't your cup of tea, but if it is, it'd be very interesting. I got into electronics largely because I like transforming what other people see as waste, into useful resources again. I've spent many hundred hours in my garbage room, salvaging parts, working electronic gadgets and also repairing and giving away or selling cheap. Through your channel, I started building things from scratch, but I would also like to develop my repairing skills. So I'd love to see more of you, repairing things and describing the most common causes of modern electronic devices failing :)

    • @TheRainHarvester
      @TheRainHarvester 6 років тому +1

      Torgny Nordén I just fixed a cheap multimeter on video. It's so satisfying to repair trash.

    • @manuel_elor
      @manuel_elor Рік тому

      X2

  • @charyenne
    @charyenne 4 роки тому +2

    The same happened to my power supply, I wanted to charge a RC car race pack with 7.2 volts and the output of the supply was shorted. You and Electoboom helped me to repair it. The revers protection circuit in a labory power supply is like this, because it dont has any effect on the current and voltage output and vorsmall loads (inductive spikes, capacitors) this version is perfect. Its not made to protect against big current and voltages.

  • @paundra-lw1up
    @paundra-lw1up 6 років тому +178

    If Tesla hired Electroboom...
    *car exploded*
    "NO REVERSE POLARITY PROTECTION, WHO DESIGN THIS SH*T?!"

    • @prasana4047
      @prasana4047 5 років тому +3

      This cmt should go for 100 of likes

    • @GRBtutorials
      @GRBtutorials 4 роки тому +3

      At first I thought you meant Nikola Tesla and I was confused...

    • @BruceNitroxpro
      @BruceNitroxpro 4 роки тому +1

      paundra0217 , Really very funny because I don't own an electric car!

    • @MohitSharmaxp
      @MohitSharmaxp 3 роки тому +1

      Hi from 2021 Electroboom bought a Tesla

    • @Splarkszter
      @Splarkszter 2 місяці тому

      Same thought about the PSU on the video lmao

  • @thesneakinspider3193
    @thesneakinspider3193 6 років тому

    I began watching you clueless to the technical side. Now with you and some other instruction I am beginning to grasp this

  • @mircoheitmann
    @mircoheitmann 6 років тому +755

    remember kids, don't drink and charge

    • @windshield11
      @windshield11 6 років тому +7

      I bet that happens much more than you'd think. Especially if you're flying drones with the boys, then want to open some cold ones.

    • @TheSaabClinicUK
      @TheSaabClinicUK 6 років тому +18

      Thanks, there will be a new EU law out next week now.

    • @confusedwolf7157
      @confusedwolf7157 6 років тому +1

      oooh harsh

    • @paundra-lw1up
      @paundra-lw1up 6 років тому +1

      Hahaha

    • @gorillaau
      @gorillaau 6 років тому +4

      And be careful where you discharge... and never in a public place.

  • @ZenPanda2023
    @ZenPanda2023 6 років тому +1

    Finally. We'll be able to see what's inside after so many long years and countless videos in attendance.

  • @superdupergrover9857
    @superdupergrover9857 6 років тому +257

    is it just me or is that the coolest looking heatsink? (1:33)

    • @h3Xh3Xh3X
      @h3Xh3Xh3X 6 років тому +66

      It's either that or the most intense fleshlight...

    • @pwnmeisterage
      @pwnmeisterage 6 років тому +19

      Looks kinda mean. But also doesn't look very efficient, probably why it's an uncommon design, lol.

    • @iblesbosuok
      @iblesbosuok 5 років тому +1

      Jealuosy

    • @hariharanb785
      @hariharanb785 5 років тому +4

      It'd nice if you could run a high static pressure fan sealed on that.

    • @sebagomez4647
      @sebagomez4647 5 років тому +3

      It is indeed the coolest looking heatsink

  • @hqiu6828
    @hqiu6828 3 роки тому +1

    Just made the same mistake and blew my small 30V DC-DC module. I will try this Reverse Voltage Protection method. Many thanks!

  • @melissacoleman9633
    @melissacoleman9633 6 років тому +6

    This is one of the best channels on UA-cam and because I watch this channel my electronics ability has soared. Thx

  • @FantaBH
    @FantaBH 6 років тому

    At first was thinking same video as many before but after watching you came to problem well known to me and as well finally someone who made video complete by showing right circuit at the end which will protect power supply on right way.

  • @m4gmu5hell
    @m4gmu5hell 6 років тому +10

    Wow. Very nice to see a new GreatScott video on Friday ^^ I actually destroied a power supply at work also by connecting a big 12V Lead acid battery the wrong way around. Should have used this circuit ^^ Thanks for the advice!

    • @renatoturkovic4299
      @renatoturkovic4299 6 років тому +5

      How Friday?Its uploaded on sunday!10 minutes ago!How is this comment old 2 days?ARE YOU TIME TRAVELING!!!

    • @luongmaihunggia
      @luongmaihunggia 6 років тому

      *destroyed

    • @m4gmu5hell
      @m4gmu5hell 6 років тому +6

      @@renatoturkovic4299 Patreon ma boiis ^^

    • @ahmedsiddiqui9515
      @ahmedsiddiqui9515 6 років тому

      How your comment is 2 days old ?

    • @m4gmu5hell
      @m4gmu5hell 6 років тому +1

      @@ahmedsiddiqui9515 Patreon ma boii ^^

  • @hannes7893
    @hannes7893 6 років тому +1

    hey that's such a coincidence. I did the same a week ago and now am able to repair mine as well, thanks a lot

  • @PelDaddy
    @PelDaddy 6 років тому +20

    You might throw in a warning to test this out with a lower current battery rather than a high current SLA battery. A 12V SLA battery can easily dump enough current to fry decent sized wires and start fires. Don't ask me how I know. Always use a fuse with such batteries.

    • @dwikey_98
      @dwikey_98 Місяць тому

      in fact, he used not only the fuse..
      in the video, the fuse is not popped because the mosfet stays off while reverse voltage and current happens..
      so the fuse only is not enough.. because the reverse voltage and current is already flows to the circuit before the fuse popped.. even the diode can blown up if that matter happens..
      but many electronics has no fully proper reverse polarity protection.. fuse and diode can prevent this..
      but, the diode can be very hot while reverse polarity happens.. and waste the power in form of heat, and even can blown up the diode if the voltages and current was too big..
      so the fuse is the last defender.. and mostly the current surge was already flowing to the circuit with harmful amount of current before the fuse is blown.. and the electronics circuits may already broken if that happens..
      so, the video is describing the whole point of this matters..

  • @tf3confirmedbuthv54
    @tf3confirmedbuthv54 6 років тому +1

    Your videos got me into this kinda thing and ended up convincing me to get a career in electrical engineering. Thank you

  • @evgerven1
    @evgerven1 6 років тому +9

    Inspite your explanation, I would still go for the reversed diode but added with a (reachable!) fuse. As in a good PSU design, the sensewires should be connected as close as possible to the load. The fuse can be quite overdimensioned compared to the PSU maximum current as the PSU has its own short circuit protection.

  • @junuhunuproductions
    @junuhunuproductions 6 років тому +2

    GREAT video! It was a little tricky to understand why fuse kept blowing & mosfet kept conducting currents when reverse-battery-voltage was applied, but all in all, great!

  • @kardeef33317
    @kardeef33317 6 років тому +4

    I don't know if its just me, but the whole video from start to finish seemed like it was running 10% faster then normal. Awesome video and thanks again for sharing your knowledge.

  • @boblewis5558
    @boblewis5558 4 роки тому +1

    There is another use to which an FET switch maybe used to good effect (no pun intended) and that is where you have a backup battery connecting to a circuit powered normally by an external source e.g. mains derived supply and where you want the battery to take over instantly on input power failure such as a bulkhead emergency light, especially as where I have one - above the fuseboard! An N-Channel FET can be used so that while the input source is present no battery current is used and no reverse current is possible either. Once the mains supply drops, the light turns on. Quite often, in fact usually, such lights are ALWAYS on and the battery constantly on charge and it just takes over on power fail. Not always what is required.
    Another similar usage is when an external charging voltage/current is going to be used to deliver charge current via an internally fitted DC-DC converter. e.g. external charge voltage of say 16 volts via a buck converter providing a 12.6 volt charging voltage to a 3S battery pack. In such cases the output of the charger (DC-DC Buck converter) cannot be left connected permanently to the battery since it will be receiving reverse voltage from the battery when the device is switched off and no external charge voltage is present.
    Fitting a single N-Channel FET with its Gate tied LOW to ground via say a 10k resistor i.e. turning off the gate, BUT a second gate resistor of 100k is connected to the INPUT charge voltage point of the buck converter. The output of the buck converter connected to the Drain, and the Source to the battery to be charged. When the charge voltage is present and the device turned off, the FET will turn on provided the input voltage of the buck converter is such that the difference between it and the output voltage is higher than the FET gate threshold, the output turns on and starts charging.
    I have recently used this exact technique to replace the old NiMh cells with Liion cells of TWO Dustbuster hand held vacuums and fitted internal charge circuits to them instead that operate in exactly this way so that when they are off and placed in their charge cradles (which can now be powered by ANY convenient 16-35 volt DC supply) they charge fine. As soon as they are unplugged the FET switches off and prevents the battery from reverse connection to the output of the buck converter which would otherwise drain the battery and also turn on the converter's output LED via the back-fed current!! This works GREAT. Especially as all the components needed were recovered from motherboards and suchlike! I included a BMS of course but also a battery status display with a button to manually show the state of charge when required but also it's auto switched by another FET when connected to the charge power.

  • @TheHeretic2011
    @TheHeretic2011 6 років тому +215

    The best reverse polarity safety is a full wave rectifier.

    • @backdoornutzer4461
      @backdoornutzer4461 6 років тому +52

      *BRIDGE

    • @Eratas1
      @Eratas1 6 років тому +17

      FUULLLLLLLLL...

    • @satibel
      @satibel 6 років тому +64

      FOOOOOOOOOOOOOL BRIDGE RECTI-FIRE!

    • @jayzo
      @jayzo 6 років тому +11

      Although you might have issues with higher loads. I put reverse current protection diodes on an LED driver I build with a dual power supply to stop each supply trying to force current through the other supply in reverse and tried forcing 5A through it (current required by the LEDs). Despite being rated for 10A a LOT of smoke came out of them and they exceeded 100C by the time I'd noticed.

    • @johndah4x0r21
      @johndah4x0r21 6 років тому +13

      +ElectroBOOM FOOL BRIDGE REKTIFAIIA!

  • @zeljkovelikipopovic
    @zeljkovelikipopovic 6 років тому

    Hvala Vam puno na korisnim savetima na vašem kanalu.
    Thank you very much for the helpful tips on your channel.

  • @BharatMohanty
    @BharatMohanty 6 років тому +334

    I guess this topic belongs to #electroboom 😀

    • @omhekde
      @omhekde 6 років тому +1

      Lol...

    • @paundra-lw1up
      @paundra-lw1up 6 років тому +45

      If Tesla hired Electroboom...
      *car exploded*
      "Damn, I put the electrolyte capacitor in the wrong way!"

    • @BharatMohanty
      @BharatMohanty 6 років тому +5

      @@paundra-lw1up if Tesla hires electroboom he will electrify that factory's environment and that will be a shocking experience for all workers.

    • @paundra-lw1up
      @paundra-lw1up 6 років тому

      @@BharatMohanty LMAO

    • @bkzzzzz
      @bkzzzzz 6 років тому +6

      yea with SHUNT and FULL BRIDGE :)

  • @Jindraxx20
    @Jindraxx20 5 місяців тому

    Thank you Scot for this content. It was very interesting the part regarding voltage vs current source protection.

  • @vedant3321
    @vedant3321 6 років тому +30

    You mentioned electroboom finally 😍

  • @kepi765
    @kepi765 6 років тому

    Genau mir ist auch leider der selbe Fehler passiert, aber gut dass es GreatScott gibt!

  • @ugetridofit
    @ugetridofit 6 років тому +3

    There are circuits that use a relay in line with the load. The coil is driven by a circuit that detects very low reverse voltage and opens the relay.

  • @Samuel-km5yf
    @Samuel-km5yf 5 років тому +1

    This is great! I just permanently modified my power supply by putting one of these circuits inside it. Now I’ll never have to worry about connecting it in reverse again!

  • @dawnminilla9299
    @dawnminilla9299 4 роки тому +4

    the circuit you found is a poor solution because after it is used once you have to remove the gate charge as the fet will stay conducting and when you try to hook a battery backwards it will be a short for a moment until the gate capacitance is discharged and the current can well exceed the maximum allowed by the fet. This generally will not fail right away but it does as I've built this exact circuit years ago for a charger we use at work and they fail about every 6 to 8 months. After an exhaustive look into the failure mechanism this is what I found. I measured sharp spikes in the 1000's amps using an irl60b216 once conducting and hooked up in reverse to a car battery

  • @packratswhatif.3990
    @packratswhatif.3990 6 років тому +1

    Haha, been there - none it (blowing up my power supply). But you do have to love the power mosfet versions ! Just build it into your power supply and change the point where your power supply monitors the output voltage to the output of the mosfet protection circuit.

  • @rich1051414
    @rich1051414 6 років тому +3

    Why use a silicone solution when you can use a relay for reverse voltage protection? Pricey, but you get no voltage drop, no heat generation. It surprises me how so few people show using a relay to make a truly ideal diode.

  • @xyzxyz-y1b
    @xyzxyz-y1b 9 місяців тому +1

    you can use a simple full bridge rectifier

  • @eformance
    @eformance 6 років тому +8

    Doesn't the cut-in voltage of the MOSFET limit the minimum voltage you can output from the power supply? It would seem to me that a virtual zener that drives a N channel MOSFET, via a proper driver chip, would be another solution with fewer drawbacks. N-channel MOSFETs tend to have a lower resistance too.

  • @magicianofelectronics951
    @magicianofelectronics951 4 роки тому

    I have destroyed one of my boost converter(bought after seeing on your channel), by connecting 3.7V 18650 battery in reverse, that is why I'm here, but in my case, diode will be good as I want to operate a solenoid mechanism for approximate 2 seconds, thank you

  • @Shocker99
    @Shocker99 5 років тому +3

    7:45 This isn't a new design. I've seen this circuit 15+ years ago. Depending on how you design it, it can also double a basic step down regulator.

  • @bjl1000
    @bjl1000 4 роки тому

    I can't believe you spent almost 9 minutes on this!

  • @GRBtutorials
    @GRBtutorials 6 років тому +7

    And that's what "ideal diodes" are made of.

  • @monkeymanstones1
    @monkeymanstones1 6 років тому +1

    I always check each and every connection with my multimeter before plugging power in and I check the battery terminals for current directivity before plugging anything in. Quick, easy and as safe as you can hope for (unless you're wearing jewelry - Example if you have a ratchet/socket in your Right hand and touch your socket to either terminal and don't realize you're touching your Left hand's wedding ring to the other terminal you instantly die as the power moves straight across your heart [it's right between your 2 arms & hands!] but good luck convincing anyone to remove their wedding rings when doing such work!).

  • @pauljackson2126
    @pauljackson2126 6 років тому +37

    What if I add a FULL BRIDGE REKTIFIYAA.......?

  • @tameralsebaee1433
    @tameralsebaee1433 6 років тому +1

    Thanks for video
    We can use a relay with a diode to protect from wrong polarity without voltage drop
    But must use same voltage for relay coil and for the load

  • @runforitman
    @runforitman 6 років тому +7

    No power supplies were harmed during the making of this video

  • @xero110
    @xero110 6 років тому

    With this added information I’ll be making my own bench top power supply. Great video, thanks.

  • @rafgaming709
    @rafgaming709 6 років тому +4

    Make a tube amp please! I know it is easier with solid state stuff but transistors will never beat the warm sound of tubes!

  • @BHAVYAMATHURBEE
    @BHAVYAMATHURBEE 6 років тому +1

    Amazing video man! However you should have gone with the N-Channel MOSFET. N-Channel MOSFETs are generally way more cheaper, has a lower Rds(on) and gate junction capacitance. Means its cheap and power efficient.
    Keep making these videos man. I'm totally a fan. And I will see you next time!

  • @petzi8695
    @petzi8695 6 років тому +32

    Make a tube amplifier

  • @tannimkyraxx
    @tannimkyraxx 6 років тому +1

    Failing to add some reverse polarity protection to my bitx40 ham radio, and subsequently figuring out how to stuff all the magic smoke inside sucked, but actually advanced my skills quite a bit.

  • @sergeantseven4240
    @sergeantseven4240 6 років тому +5

    This is probably why using a lab power supply to charge a battery is not recommended. Battery charging circuits have protections built in for this reason.

    • @GrulbGL
      @GrulbGL 5 років тому +1

      Yeah... just a diode in series, than compensate the voltage...

  • @mupschiplayz1802
    @mupschiplayz1802 6 років тому +1

    FINALLY a new video from Scott

    • @greatscottlab
      @greatscottlab  6 років тому +1

      Every Sunday ;-)

    • @mupschiplayz1802
      @mupschiplayz1802 6 років тому

      Hey GreatScott,
      Could you give me the Amazon Link with i can support you?

  • @doufasmilz485
    @doufasmilz485 6 років тому +5

    Can you do an ups?

  • @Albert-fe1xn
    @Albert-fe1xn 4 роки тому

    I almost watched all of your videos, Not knowing Im not yet subscribe, and Now I subscribed that's why I made a Comment. HAHAHA. GREAT VIDEOS VERY INFORMATIVE AND HELPFUL. WATCHING FROM THE PHILIPPINES 😂

  • @QLTD
    @QLTD 6 років тому +3

    I prefer sticking with the original method to get accurate voltage also mistakes happen once I don't think I will blow the diode again in the future 🙂

  • @InFAMOUSPS4_19
    @InFAMOUSPS4_19 2 роки тому +2

    When are we going to see a collaboration video between these 2? I know the distance is pretty great but still something I'd love to see in the future.

  • @ponchov.9116
    @ponchov.9116 5 років тому +12

    "It is bastards" - 0:38
    (Enable automatic subtitles)

  • @ShomiTheGreat
    @ShomiTheGreat 6 років тому

    Back to jlcpcb advertising. Cool.

  • @johnavonvincentius1884
    @johnavonvincentius1884 6 років тому +3

    What kind of power supply is it?
    What is the Max Voltage,Current and power.

  • @nil3010
    @nil3010 3 роки тому

    That heat sink looks Dope

  • @lbgstzockt8493
    @lbgstzockt8493 6 років тому +10

    this system wouldnt be as bad if the diode could be swapped more easily

    • @slrn832472577
      @slrn832472577 6 років тому +2

      Maybe mounting a perf board on the back of the power supply that contains the diode on the outside of the power supply for ease of replacement.

    • @davey2k12
      @davey2k12 6 років тому

      Could protect diode with a heavy latch relay on a separate power source disconnect the output when polarity is reversed or shorted

    • @johnfrancisdoe1563
      @johnfrancisdoe1563 5 років тому +1

      Eric Daniels Just put the diode in a fuse holder. But encouraging internal repair of lab equipment is good outside the calibration industry.

  • @kwazar6725
    @kwazar6725 6 років тому +1

    When charging batteries use a proper charger. My icharger detects all sorts of misconfigurations and as scotty said prevents fire..... you can get ics spevially made for a multitude of reverse current reverse polarity short cct and more.....

    • @kwazar6725
      @kwazar6725 6 років тому

      Scott . Maybe build an external all singing and dancing super protector with meters and leds. Maybe use the ltc devices or whatever...

  • @Mrugendraa
    @Mrugendraa 6 років тому +10

    Best way for Reverse Voltage protection is
    DO NOT MESS WITH ELECTRONICS WHILE YOU R DRUNKED...!!! ;P
    ●●●●●●●●●●●●●●●●●●●●●●●

  • @Kaspar_NL
    @Kaspar_NL 6 років тому

    Really great vid to show the 'flaw' of the design of your power supply including a fix!

  • @Asu01
    @Asu01 6 років тому +107

    Pfft, reverse polarity protection is only for the weak.

    • @MCsCreations
      @MCsCreations 6 років тому

      😂

    • @HobkinBoi
      @HobkinBoi 6 років тому +11

      Yep. Once you blow something up, you almost always remember to make sure you set up correctly.

    • @BadMax02_VR
      @BadMax02_VR 6 років тому +4

      if you work at a atomreactor you also dont a second chance yo make sure to always connect correctly or just thing that your city will blow up xD

    • @domino52o26
      @domino52o26 6 років тому +6

      @@BadMax02_VR
      Technically not true but it was good humor. 7/10

    • @confusedwolf7157
      @confusedwolf7157 6 років тому

      quick...lets get to the chopper

  • @RyutakuZaki
    @RyutakuZaki 6 років тому +2

    From the beginning Hehe I knew that you got inspired by electro boom. My two favorite channels :D

  • @paundra-lw1up
    @paundra-lw1up 6 років тому +28

    Ft. Electroboom

  • @kenmore01
    @kenmore01 3 роки тому

    You had too much to drink. I applaude your candor!

  • @mattv9989
    @mattv9989 6 років тому +15

    uploaded 52 seconds ago, a comment from 2 days ago..........

    • @greatscottlab
      @greatscottlab  6 років тому +28

      Patreon supporters can watch earlier.

    • @mattv9989
      @mattv9989 6 років тому +5

      oh that makes much more sense :D

    • @beedslolkuntus2070
      @beedslolkuntus2070 6 років тому

      @@greatscottlab Do you have patrons plans like rewards electroboom has 6 reward types....

    • @Dust599
      @Dust599 6 років тому +2

      the privilege of wealth...

    • @confusedwolf7157
      @confusedwolf7157 6 років тому +1

      that...is...sooooo specific

  • @nassimkoubeissi5814
    @nassimkoubeissi5814 5 років тому

    Great tutorial
    You can use a thyristor with a relay
    When a reverse voltage detected by thyrisyor it triggers the relay and opens its switch note to use a
    Fast acting relay .

  • @renatoturkovic4299
    @renatoturkovic4299 6 років тому +7

    I never had problem with reverse voltage

    • @danfishermen5362
      @danfishermen5362 6 років тому +1

      I had

    • @RyutakuZaki
      @RyutakuZaki 6 років тому +7

      1) you are starting with electronics
      2) you’re a liar

    • @andrewkieran8942
      @andrewkieran8942 6 років тому +6

      There only two kinds of electronics hobbyists, those that have done this and those that will.

    • @roygalaasen
      @roygalaasen 6 років тому +3

      Until one day you had a problem with reverse voltage.

    • @renatoturkovic4299
      @renatoturkovic4299 6 років тому +1

      @@RyutakuZaki Every time when I make circuit I always double check or triple check circuit for reverse polarity supply or capacitors

  • @agstechnicalsupport
    @agstechnicalsupport 5 років тому

    Thank you for posting such an instructive and practical video on reverse voltage protection circuits !

  • @beedslolkuntus2070
    @beedslolkuntus2070 6 років тому +12

    someone say hi to me....
    Hi you person reading the comments!! have a good day

    • @MRA_3
      @MRA_3 6 років тому +1

      Hello,how are you ?

    • @satibel
      @satibel 6 років тому +2

      hi to me....

    • @araigumakiruno
      @araigumakiruno 6 років тому +1

      hi from malaysia

    • @sam_8a
      @sam_8a 6 років тому +1

      hi to me

    • @dalenassar9152
      @dalenassar9152 6 років тому

      Greetings and salutations from way down south in Amite, Louisiana. Where are you?

  • @Unmannedair
    @Unmannedair 6 років тому

    Nice demo. Will probably use.

  • @gonun69
    @gonun69 6 років тому +3

    Didn't watch the video yet. But... FULL BRIDGE RECTIFIER!

    • @hedgehogthesonic3181
      @hedgehogthesonic3181 6 років тому

      And what is a *FULL BRIDGE RECTIFIER!* ?!?!?!?!?!?!?!
      I know it have some capacitors and stuffs but the function of it is unknown for me...

    • @DFX2KX
      @DFX2KX 6 років тому

      @@hedgehogthesonic3181 It's an arrangement of diodes that turns A/C current (which goes back and forth both ways) into DC current.
      It's not efficient however.

    • @hedgehogthesonic3181
      @hedgehogthesonic3181 6 років тому

      @@DFX2KX DC only moves in one direction right ?

  • @freddymercury8556
    @freddymercury8556 6 років тому +2

    Coincidence......that happened to me a week ago as well. Feels like God answer my prayers!

  • @DrHarryT
    @DrHarryT 6 років тому +3

    "What is the best Reverse Voltage Protection Circuit?"
    As it has been for years...A diode and a fuse.

  • @Niaiss
    @Niaiss 6 років тому

    Интересное решение с минимум деталей.👍электронный предохранитель и блок защиты👍

  • @nasimakhanam2445
    @nasimakhanam2445 6 років тому +1

    This is really a useful video

  • @tyttuut
    @tyttuut 6 років тому

    I made a similar mistake with my $300 Rigol DP712. Fortunately their warranty is awesome.

  • @wimwiddershins
    @wimwiddershins 6 років тому

    Great video. This problem comes up often.

  • @Krunalbhongade
    @Krunalbhongade 6 років тому +1

    The diode in parallel is added generally to damp transient voltages which might happen during inductive loads... This parallel diode also happens to act as a reverse polarity protection.
    That parallel diode might be a TVS or a schottky diode.

  • @chrismofer
    @chrismofer 6 років тому +2

    you could put a latching relay and diode to have close to no voltage loss and still a fiarly fast decoupling on reverse voltages

  • @ARandomTroll
    @ARandomTroll 4 роки тому

    you should do a video on active rectifiers and more "mosfet as diode" usecases. would be great for electrolysis power supplies.

  • @sylkelster
    @sylkelster 4 роки тому +1

    I have noticed an inverse relationship in bench power supplies between Chinesium and on-board circuit protection, with high accuracy.

  • @rupantaradhikary1482
    @rupantaradhikary1482 6 років тому

    Electrobooms inverter is nice example and its a another interesying video

  • @BjornV78
    @BjornV78 4 роки тому

    7:47 I think this is the type of protection that is used in modern commercial car batterychargers (trickle loader), they don't charge when the battery is below a certain voltage,
    and the + and - outputs are shortcircuit protected, because they don't carry a voltage when there is no battery connected.

  • @julienbonal1841
    @julienbonal1841 6 років тому

    Incredible ! It was what i was looking for to charge lithium battery with 220v to 5v supply. Because the 0.7v drop of the diode prevent it from completely charge le lithium battery. I hope the lower drop voltage of the mosfet will be ok !

  • @ACTlVISION
    @ACTlVISION 6 років тому

    Can you make a video for "fast" charging multiple LiPo/18650s in parallel with parallel TP4056s and maybe polarity and overcurrent protection? Would be cool to see an alternative to buying a BMS and having a regulated charge voltage for "simpler" projects, since it's quite a bit cheaper. Keep up the awesome videos!

  • @zarielandaluz7710
    @zarielandaluz7710 6 років тому

    Excellent solution, regardless of the voltage dropping which can be calibrated with a predefined fine tuning and clear the offset. Can you make a video about charging/discharging super capacitors?

  • @МаксимГрищенко-н1с

    An IRL5602S transistor can be used to protect a circuit with low power - 3.8 - 5 volts. It opens completely from the logic level of the signal (2-4 volts).

  • @damiandassen7763
    @damiandassen7763 6 років тому

    Can you do a video on your schematics drawing techniques. They are very neat and it would be nice to be able to draw them like yours.

  • @usmanumer9871
    @usmanumer9871 6 років тому

    your voice is splendid

  • @freda5344
    @freda5344 6 років тому

    sense the reverse current and mod the psu voltage f/b circuit - best way to fix this problem. Just a resistor/bjt sense on the reverse diode circuit.

  • @arphyl2815
    @arphyl2815 4 роки тому +1

    Quick question: Why not use an H-bridge config at the output rails? To make sure that the + and - rails remains as is. We used that in our project. 🤔 Although I see that the power efficiency and voltage drops will be some considerations.

  • @howardwang4348
    @howardwang4348 4 роки тому +1

    Add a relay and a shunt in series ,then use opamp to monitor the reverse voltage on the shunt, the opamp is triggered by reverse voltage and lock its output to trigger the relay to protect everything.
    I think my idea is the most efficient and reliable.

    • @greatscottlab
      @greatscottlab  4 роки тому

      Yes, using a relay is always very power efficient......

    • @MrAbrandao
      @MrAbrandao 4 роки тому

      perheaps a comparator and a relay ? but will the relay be fast enough?

  • @sudipbabudhakal7236
    @sudipbabudhakal7236 6 років тому

    We can use bridge rectifier as well, if drop of 2*0.7 voltage is acceptable with some power loss as well. Afterall device is protected as well, We can power up with any type of connection, either reverse or forward, and it work flawlessly for small power circuit.

    • @Loundre3
      @Loundre3 6 років тому

      Or using something like this:
      www.ti.com/tool/tida-00858?keyMatch=smart%20bridge%20rectifier&tisearch=Search-EN-Everything

    • @noweare1
      @noweare1 6 років тому

      Loundre3 Nice, thanks for that.

  • @Detonador7G
    @Detonador7G 4 роки тому

    Hey, I might be a bit late but at 5:27 the mosfet in ON so the diode is shortened, and therefore you don't have that 1.3V drop.

  • @naderhumood
    @naderhumood 5 років тому +2

    Great vedio God bless you and your power supply. ....👍

  • @bjtaudio
    @bjtaudio 5 років тому

    Try a SUP53P06-20 its on resistance is only 0.02Ohm for even less voltage drop. I would suggest mosfet protection, using a 10K resistor between the gate and -ve and strap a 12V Zener to clamp the gate voltage.

  • @bob71014
    @bob71014 6 років тому

    Intro was one of my favorite

  • @brendansmith9677
    @brendansmith9677 6 років тому

    Great video! I will have to add this to the power supply I plan to build.