What is the best Reverse Voltage Protection Circuit? || Repairing a Lab Bench Power Supply
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- เผยแพร่เมื่อ 2 พ.ค. 2024
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In this video I will show you how I repaired my lab bench power supply which got damaged through a battery which I connected the wrong way around. Along the way I will show you different reverse voltage protection techniques and show you their advantages and disadvantages. This way you will hopefully never damage your lab bench power supply like I did.
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Music:
2011 Lookalike by Bartlebeats - วิทยาศาสตร์และเทคโนโลยี
I feel ... included! :D
ElectroBOOM where them free oscilloscopes at 👀
ElectroBOOM FUUULLLLBRIIIDGEEEETEKKTIFAIAAAAA
so few seem to have seen this comment
Vodka + The smartest EE (electrical engineer) = *Bang!* [F--k! Sh--! What is this!? Ahh-F--k!]
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
That power supply has the weirdest heatsink I've ever seen and I love it
It’s so cool!
BTW it’s common in other ELV LabPSUs as well :)
Xbox One heatsinks are kinda strange too lol
@@bretsutherlandsterriblemem8439 YOU BETCHER LIFESAVERS-!!!
Maybe the power supply gets hot quickly. So the big heat sink is used to make it cool. Why am I so nerd😂
@@ejezragaming2187 very clever observation
If Tesla hired Electroboom...
*car exploded*
"NO REVERSE POLARITY PROTECTION, WHO DESIGN THIS SH*T?!"
This cmt should go for 100 of likes
At first I thought you meant Nikola Tesla and I was confused...
paundra0217 , Really very funny because I don't own an electric car!
Hi from 2021 Electroboom bought a Tesla
remember kids, don't drink and charge
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.
Thanks, there will be a new EU law out next week now.
oooh harsh
Hahaha
And be careful where you discharge... and never in a public place.
is it just me or is that the coolest looking heatsink? (1:33)
It's either that or the most intense fleshlight...
Looks kinda mean. But also doesn't look very efficient, probably why it's an uncommon design, lol.
Jealuosy
It'd nice if you could run a high static pressure fan sealed on that.
It is indeed the coolest looking heatsink
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.
Scott always impresses me with his soldering skills. Amazing as always.
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 !
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 :)
Torgny Nordén I just fixed a cheap multimeter on video. It's so satisfying to repair trash.
X2
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.
Your videos got me into this kinda thing and ended up convincing me to get a career in electrical engineering. Thank you
With this added information I’ll be making my own bench top power supply. Great video, thanks.
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
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!
How Friday?Its uploaded on sunday!10 minutes ago!How is this comment old 2 days?ARE YOU TIME TRAVELING!!!
*destroyed
@@renatoturkovic4299 Patreon ma boiis ^^
How your comment is 2 days old ?
@@ahmedsiddiqui9515 Patreon ma boii ^^
Hvala Vam puno na korisnim savetima na vašem kanalu.
Thank you very much for the helpful tips on your channel.
I have to respect someone who makes such clean schematics. Subscribed.
This is one of the best channels on TH-cam and because I watch this channel my electronics ability has soared. Thx
Nice. Glad you like it.
The best reverse polarity safety is a full wave rectifier.
*BRIDGE
FUULLLLLLLLL...
FOOOOOOOOOOOOOL BRIDGE RECTI-FIRE!
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.
+ElectroBOOM FOOL BRIDGE REKTIFAIIA!
Finally. We'll be able to see what's inside after so many long years and countless videos in attendance.
Really great vid to show the 'flaw' of the design of your power supply including a fix!
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.
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.
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
Thank you for posting such an instructive and practical video on reverse voltage protection circuits !
Allways be safe use protection
I guess this topic belongs to #electroboom 😀
Lol...
If Tesla hired Electroboom...
*car exploded*
"Damn, I put the electrolyte capacitor in the wrong way!"
@@paundra-lw1up if Tesla hires electroboom he will electrify that factory's environment and that will be a shocking experience for all workers.
@@BharatMohanty LMAO
yea with SHUNT and FULL BRIDGE :)
You mentioned electroboom finally 😍
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.
Great video! I will have to add this to the power supply I plan to build.
No power supplies were harmed during the making of this video
Fuses is probably another story
Actually 1 power supply was repaired
And that's what "ideal diodes" are made of.
I began watching you clueless to the technical side. Now with you and some other instruction I am beginning to grasp this
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.
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.
What kind of power supply is it?
What is the Max Voltage,Current and power.
ELV DPS5315 0-30V 0-3A
Just made the same mistake and blew my small 30V DC-DC module. I will try this Reverse Voltage Protection method. Many thanks!
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!
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.
What if I add a FULL BRIDGE REKTIFIYAA.......?
FOOL BRIDGE*
God dammit
Electroboom hahahaha
Zen you vill haf 1.4V drop across it and you missed the point.
Voltage drop, but it would work
Most interesting subject! Thanks for sharing and keep up your great work!
THANKS!!! I been needing this kinda info!
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.
Yeah... just a diode in series, than compensate the voltage...
"It is bastards" - 0:38
(Enable automatic subtitles)
Thank you for this vídeo Scott
Thanks for sharing😀👍
Interesting project
A good solution for a common problem👍😀
Make a tube amplifier
this system wouldnt be as bad if the diode could be swapped more easily
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.
Could protect diode with a heavy latch relay on a separate power source disconnect the output when polarity is reversed or shorted
Eric Daniels Just put the diode in a fuse holder. But encouraging internal repair of lab equipment is good outside the calibration industry.
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
Great vedio God bless you and your power supply. ....👍
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 🙂
Make a tube amp please! I know it is easier with solid state stuff but transistors will never beat the warm sound of tubes!
Lel
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 .
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.
Best way for Reverse Voltage protection is
DO NOT MESS WITH ELECTRONICS WHILE YOU R DRUNKED...!!! ;P
●●●●●●●●●●●●●●●●●●●●●●●
no shit sherlock
Can you do an ups?
Up
this is good for my knowledge electronic thank for this video hope you get more like this and stay well for your healthy
Very well said @GreatScott. Good Job
Ft. Electroboom
Pfft, reverse polarity protection is only for the weak.
😂
Yep. Once you blow something up, you almost always remember to make sure you set up correctly.
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
@@BadMax02_VR
Technically not true but it was good humor. 7/10
quick...lets get to the chopper
Genau mir ist auch leider der selbe Fehler passiert, aber gut dass es GreatScott gibt!
Nice demo. Will probably use.
uploaded 52 seconds ago, a comment from 2 days ago..........
Patreon supporters can watch earlier.
oh that makes much more sense :D
@@greatscottlab Do you have patrons plans like rewards electroboom has 6 reward types....
the privilege of wealth...
that...is...sooooo specific
I never had problem with reverse voltage
I had
1) you are starting with electronics
2) you’re a liar
There only two kinds of electronics hobbyists, those that have done this and those that will.
Until one day you had a problem with reverse voltage.
@@RyutakuZaki Every time when I make circuit I always double check or triple check circuit for reverse polarity supply or capacitors
Thanks for sharing this knowledge
Man you are incredible
Thank you so much
someone say hi to me....
Hi you person reading the comments!! have a good day
Hello,how are you ?
hi to me....
hi from malaysia
hi to me
Greetings and salutations from way down south in Amite, Louisiana. Where are you?
"What is the best Reverse Voltage Protection Circuit?"
As it has been for years...A diode and a fuse.
Intro was one of my favorite
Thank you. Very informative video
Didn't watch the video yet. But... FULL BRIDGE RECTIFIER!
And what is a *FULL BRIDGE RECTIFIER!* ?!?!?!?!?!?!?!
I know it have some capacitors and stuffs but the function of it is unknown for me...
@@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.
@@DFX2KX DC only moves in one direction right ?
you could put a latching relay and diode to have close to no voltage loss and still a fiarly fast decoupling on reverse voltages
the best electronics video. great!
This is really a useful video
From the beginning Hehe I knew that you got inspired by electro boom. My two favorite channels :D
Thank you for your time and effort to produce these excellent videos! You appear well versed in MOSFET selection. I have a reverse voltage polarity 6 - 8 VDC, 15 AMP (max) application I am evaluating that will require a low side N-Channel MOSFET. Any initial suggestions?
very clear explanation
FINALLY a new video from Scott
Every Sunday ;-)
Hey GreatScott,
Could you give me the Amazon Link with i can support you?
Amazing!! Gotta make it ..
Thanks for sharing 👍
Thanks you great scott ! I am a big fan of yours!
Can you make a voltage increasing circuit upto 1000v or 2000v?
Great video. This problem comes up often.
Well explained.
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!).
Thanks Scott
I've been working on a guitar effects pedal project and it needs reverse protection polarity. Some designs I've seen use the parallel diode setup like in your power supply but I've read a series diode is better. Planning to use a NTE585.
The mosfet design is also out there and I'm considering it, but I think the diode is easier to implement.
thank you dude!
Great Scott is really Great....
great scott you are genius
Love your videos my friend. U rule
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.
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.
Very interesting and helpful.
I liked very much the kind of brand or pens used it's wonderful
Very good info
That heat sink looks Dope
love your videos enjoy your day
Thanks
+GreatScott! ok
You instructions are too good
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?
Electrobooms inverter is nice example and its a another interesying video
What soldering station do you recommend? I was looking to get a new one.
Useful video 👍 Excellent 👍