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
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 !
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.
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 :)
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.
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.
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!
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.
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.
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.
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.
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.
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!
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
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.
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.
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 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
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
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.
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.
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.
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!
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.
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.
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.....
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.
@@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.
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).
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 😂
NFETs are better when it comes to low RDSon values because they are better carrier mobility. ~3 for the same given area. PFETs will also work but if we are optimizing...
Some power supplies do not like power being supplied from the battery when the power supply is off. The old kings hill bench power supplies were damaged if the power supply was turned off with the battery still connected. My colleagues and I discovered this when the lab earth leakage circuit breaker was tripped while charging some lead acid batteries. I would be interested to know if your PSU suffers the same problem. As I recall the fault was the result of latch up in the voltage control op amp circuit when mains supply was restored with the battery still connected. As far as I can tell the MOSFET circuit does not resolve this problem, as current can flow through the intrinsic reverse diode between drain and source. In the preferred circuit, would it have not been better to run the driver transistor as an emitter follower to limit the MOSFET gate voltage to Vz-vbe..
I was testing 2 different 13.8V power supplies to pump up an air mattress and by accident, I forgot to disconnect one of them while energizing the other that was also connected, I guess it didn't like backfeeding power that way as it damage BOTH of the power supplies. Do you think I should try a similar fix (replace diodes) as you illustrated here?
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 .
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.
Hey nice video. I want to protect my power supply from reverse voltage when i am charging my batteries. I dont want to make a circuit and stick to adding a diode. Now I am not an electronic engineer so sorry in advance if I made a mistake but what I found for 1N5822 is max rectified forward current is 3A so it means that max curent that can go through it is 3A but my power supply delivers upto 8A so can I add 3 diodes in parallel?
Yes it will affect the voltage regulation due to the drain to source resistance in the mosfet. A fuse to protect the diode is the simplest way to protect the PSU without affecting the voltage regulation.
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 !
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
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
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.
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
Same thought about the PSU on the video lmao
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 !
Scott always impresses me with his soldering skills. Amazing as always.
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.
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
Finally. We'll be able to see what's inside after so many long years and countless videos in attendance.
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.
I began watching you clueless to the technical side. Now with you and some other instruction I am beginning to grasp this
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.
Just made the same mistake and blew my small 30V DC-DC module. I will try this Reverse Voltage Protection method. Many thanks!
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!
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
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 ^^
Your videos got me into this kinda thing and ended up convincing me to get a career in electrical engineering. Thank you
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.
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.
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 :)
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.
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.
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.
Thank you Scot for this content. It was very interesting the part regarding voltage vs current source protection.
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.
Hvala Vam puno na korisnim savetima na vašem kanalu.
Thank you very much for the helpful tips on your channel.
You mentioned electroboom finally 😍
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!
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
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.
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.
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!).
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.
With this added information I’ll be making my own bench top power supply. Great video, thanks.
And that's what "ideal diodes" are made of.
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
No power supplies were harmed during the making of this video
Fuses is probably another story
Actually 1 power supply was repaired
Genau mir ist auch leider der selbe Fehler passiert, aber gut dass es GreatScott gibt!
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
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
"It is bastards" - 0:38
(Enable automatic subtitles)
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.
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...
FINALLY a new video from Scott
Every Sunday ;-)
Hey GreatScott,
Could you give me the Amazon Link with i can support you?
Make a tube amplifier
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.
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
I can't believe you spent almost 9 minutes on this!
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.
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!
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
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.
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 🙂
you could put a latching relay and diode to have close to no voltage loss and still a fiarly fast decoupling on reverse voltages
Can you do an ups?
Up
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.
Best way for Reverse Voltage protection is
DO NOT MESS WITH ELECTRONICS WHILE YOU R DRUNKED...!!! ;P
●●●●●●●●●●●●●●●●●●●●●●●
no shit sherlock
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.....
Scott . Maybe build an external all singing and dancing super protector with meters and leds. Maybe use the ltc devices or whatever...
What kind of power supply is it?
What is the Max Voltage,Current and power.
ELV DPS5315 0-30V 0-3A
Coincidence......that happened to me a week ago as well. Feels like God answer my prayers!
Ft. Electroboom
Would it be advisable to put a full bidge rectifier at the power input terminal so you wouldnt care too much which lead goes where?
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
From the beginning Hehe I knew that you got inspired by electro boom. My two favorite channels :D
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?
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.
Or using something like this:
www.ti.com/tool/tida-00858?keyMatch=smart%20bridge%20rectifier&tisearch=Search-EN-Everything
Loundre3 Nice, thanks for that.
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
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.
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 ?
"Horrible, inefficient, and useless" But tell us, how do you really feel?!? Love it.
"What is the best Reverse Voltage Protection Circuit?"
As it has been for years...A diode and a fuse.
you can use a simple full bridge rectifier
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).
I have noticed an inverse relationship in bench power supplies between Chinesium and on-board circuit protection, with high accuracy.
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 😂
This is really a useful video
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.
NFETs are better when it comes to low RDSon values because they are better carrier mobility. ~3 for the same given area. PFETs will also work but if we are optimizing...
Some power supplies do not like power being supplied from the battery when the power supply is off.
The old kings hill bench power supplies were damaged if the power supply was turned off with the battery still connected. My colleagues and I discovered this when the lab earth leakage circuit breaker was tripped while charging some lead acid batteries. I would be interested to know if your PSU suffers the same problem. As I recall the fault was the result of latch up in the voltage control op amp circuit when mains supply was restored with the battery still connected.
As far as I can tell the MOSFET circuit does not resolve this problem, as current can flow through the intrinsic reverse diode between drain and source. In the preferred circuit, would it have not been better to run the driver transistor as an emitter follower to limit the MOSFET gate voltage to Vz-vbe..
Really great vid to show the 'flaw' of the design of your power supply including a fix!
Thank you for posting such an instructive and practical video on reverse voltage protection circuits !
Allways be safe use protection
I was testing 2 different 13.8V power supplies to pump up an air mattress and by accident, I forgot to disconnect one of them while energizing the other that was also connected, I guess it didn't like backfeeding power that way as it damage BOTH of the power supplies. Do you think I should try a similar fix (replace diodes) as you illustrated here?
I made a similar mistake with my $300 Rigol DP712. Fortunately their warranty is awesome.
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 .
Интересное решение с минимум деталей.👍электронный предохранитель и блок защиты👍
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.
Yes, using a relay is always very power efficient......
perheaps a comparator and a relay ? but will the relay be fast enough?
Nice demo. Will probably use.
Can you make circuit for a jumper cable to protect the battery if use in the wrong way
Great video. This problem comes up often.
Hey nice video. I want to protect my power supply from reverse voltage when i am charging my batteries. I dont want to make a circuit and stick to adding a diode. Now I am not an electronic engineer so sorry in advance if I made a mistake but what I found for 1N5822 is max rectified forward current is 3A so it means that max curent that can go through it is 3A but my power supply delivers upto 8A so can I add 3 diodes in parallel?
Great video! I will have to add this to the power supply I plan to build.
Will this reverse voltage protection circuitry affect the voltage and current readings when using on load?
Yes it will affect the voltage regulation due to the drain to source resistance in the mosfet. A fuse to protect the diode is the simplest way to protect the PSU without affecting the voltage regulation.
If the PSU can supply 10A, what amp rating of fuse would be optimal as reverse protection?
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Most interesting subject! Thanks for sharing and keep up your great work!
Which was the fuse you used over there? Please specify
Is there a IC available for the circuit shown last ?
this is good for my knowledge electronic thank for this video hope you get more like this and stay well for your healthy
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 !