I have spent several years learning electronics watching UA-cam videos and I must say that you are the best teacher I have seen. Every time I watch your videos I learn something new and gain very important information to really grasp how components work in a circuit. Thank you for explaining things so well. You are the best my friend.
1 minute 30 seconds in and my mind has been blown. The amount of connections you have allowed me to make with your guidance and you make these videos for free. Hats off to you sir and much respect/admiration/gratitude sent over from across the pond! Thank you so much!
You are a true blessing to the YT community. I came to electronics later in life but through your tutelage have learned to diagnose and repair so may items that I find thrown away. I now have quite a collection of old appliances that work good as new and are no longer going to end up on landfills or fire pits. I cannot truly express how much I appreciate all the wisdom you share. You have an amazing gift, Thank you!
What an exellent teacher. I have watched dozens of repair videos, even your 2 hour GFX one. Trying to get a grasp on the numbers. I feel with this I actually understand. Thank you.
I have been watching how to videos for the last several years and it’s finally starting to click. Thanks for taking the time and explaining it well. I’ll keep watching until it all makes sense!
I'm so glad I found your channel. You've helped brush up on stuff I've forgotten since I started learning this at age 8. I'm nearly 43 so that's the vast majority of my life. I was told by plenty of seasoned techs that you always forget more than you remember as you become specialized. That's why it's so important to keep learning. Fun fact: I ended up arguing with a PhD-EE who had forgotten how capacitor discharge time-constants work. He thought the curve was more like a battery than the sharp drop it is and screwed up integrity of the sensors; +-60g crash data recorder g-force sensors. Liability much? "Oh it's okay. The NASCAR driver only sustained 8g in the crash." There was a +-6g primary g-force sensor set, but Chernobyl already shows what having sensors (Geiger counters, in that case) that top out far too low for the environment you're in can do. I took this as a strong warning to never rest on my laurels. To paraphrase Ferris Bueller: "If I'm going to get shown-up, it's not going to be by a guy like _that_."
Rich, you are an outstanding teacher of electronics. I learn more from watching your videos than anywhere else. you give just the right information and manage to distil all the more important parts. Well done my friend, there are few people who can do this really well.
The only practical applied electronics videos that I can follow. Tried for years to find the more applied part of the field not the overloaded textbook slide show. Like in cooking I just want to make a couple recipes and have a bit of fun enjoy my time, and in electronics I just want to learn and fix stuff that others would just throw away. Thank you sir, how do I send you money??
congratulations for your knowledge, especially for how you share it. You have a naturalness in explaining that makes everything simple and clear. Listening to you is very pleasant, congratulations for the knowledge you give to those who want to enter this fantastic world of electronics
Great video for anyone starting electronics and also a useful refresher for those that know a bit more. Regarding rectifies, there were also ones made from copper oxide. They looked like a stack of washers with fins. Finally, when selenium rectifies fail, they can produce an unspeakably foul smell!
Great refresher information in the video. I am not a newbie to electronics, but I appreciate your approach to introducing diodes. Great examples. You earned a like and a subscriber. Thank you for taking the time to make these videos.
Really enjoying this series of videos! Thanks so much for taking the time to make these. One question I have is between 22:29 and 24:45 where you talk about the diode that helps short out the spike in voltage when the relay turns off, why isn’t at least some of the voltage directed towards ground via the transistor?
Thanks for the tutorial on diodes, a lot good info in this video. I feel like I learned something. Min split heat pumps have become common for heating and cooling. They have a bridge rectifier and its nice to know how I can test it. Funny thing, they call those units "inverters" but thats converting from DC to AC right? Still haven't learned why they call them that. Anyway, great tutorial. Take care.
Dear sir , you forgot the use of diodes to the voltage regulators (LM317 or LM7805 ..etc) to boost the output voltage..!!! Very very useful in electronics..!! Thank you for your time.
Hello Rich , I am confused with the current flow , - to + , backwards so diodes and transistors I just don’t completely understand , I like your videos , thanks for shearing your knowledge , regards
My understanding about the diode schematic symbol is that back in the day. Current was believed to flow from positive to negative. So when the symbol was created the arrow was meant to show the direction that current could flow. Later, when it was discovered that current flows from negative to positive. The symbol was never changed to reflect this new understanding. In college, my professor taught me to think of it this way "the arrow is a car driving into a brick wall". Meaning, current can't flow in that direction. When using a diode for reverse polarity protection. Schematics have always shown the symbol with the back of the arrow towards the positive of a battery or other DC power source. This positive and negative confusion also affects the general public as well as novices when it comes to things like car batteries. As they assume positive means more of something and negative as less. So more must flow to less in order to equal out. But it is actually based on the words used to name the charge states of electrons and protons. Electrons being considered to have a negative charge and protons a positive charge. As we know today, electrons move through wires but protons do not. So negative represents the charge of the electrons that are moving through the circuit.
You can also show a rectifier as used in linear power supply, that has 2 diodes connected to a center tapped secondary, and showing/measuring HV diodes such as those used in a microwave oven, as well.
Great stuff! Happy to support your work on patreon. Even though my support is small I'm still hoping that it will at least little bit help you to continue with your excellent work.
Great presentation. Thank you. You missed zener diodes and how to test them especially reverse voltage rating (in the case of no marking to identify it).
Now now.... The first thing I said at the start of this video, is that it was only going to cover rectifier diodes Zener diodes is here ua-cam.com/video/trjbHhLERic/v-deo.html Enjoy
@@LearnElectronicsRepair I did watch that video and I watched it again. Great stuff!! I would like you to address identifying defective zener rating in circuit especially when schematic circuit is not available. Much appreciated!
I've got a question about an oscilloscope a neighbor recently gave me. It is an old Phillips 25 megaherz 2 channel model. The power cord is only two terminal with no earth ground pin. Does this mean that this unit is isolated (as in a linear isolated PS) and safe to use without the use of an isolation transformer? Thanks and I do enjoy your videos.
I just fixed an inverter and I could not believe the diode tested correctly with meter but when in circuit it dropped 8volts of a 12v supply. Never seen it before and doubted everything I knew about diodes. Replaced and all ok.
In German the connections are called Anode and Kathode. Makes up for an easy mnemonic trick, which half works in English as well. First the multilanguage one. With the top half of the A of Anode you form the triangle part of the diode. And with the K of Kathode you can imagine forming the line and the top part of the triangle. This way you can easily figure out which is which. 🤗
If you flip the diagram so that the bar is on top, you can view the triangle as kind of an A(node) with a C(athode)ross bar that became floaty and ended up on top. I just invented this memory aid. Feel free to use it as you please.
Hello Richard, can you tell me how to know white smd LED chip working voltage? If voltage drop use diode test mode show 2.5v. Can it be the working voltage of led is 3 volt? And not 6v or 9v
LEDs require a constant current supply. You can use 3V 6V or 9V supply but you must put a resistor in series with the LED to limit the current, or for higher power LEDs use something like LM317 voltage regulator wired as a constant current source lednique.com/power-supplies/lm317-constant-current-power-supply/
Thanks you so much. So if i use adjustable power supply, i am not should use resistor right? I just should increase the current from the smaller right?
any chance you could change your mobile phone alert notification sound? I'm using the same sound and every time I watch your video you get a message and I think it's my phone going off, I go to check and nothing :(
looking for days trying to find the voltage on a dell xcr8d 0v62h atx 8 plug 240 w power supply. when checking the purple wire i have 12v and mobo not starting is that a dell standard or should it be 5.5v replaced with new 255w psu still 12v, any ideas
It sounds strange they would change the ATX standard, and use 12V Standby on the purple wire, but who knows if they are making proprietary PSU and Motherboards with unusual connectors. Are you saying the PSU does not have the normal 24pin ATX connector?
Hi 👋🏾 I have an factory fitted infotainment system in the car (radio,bluetooth and satnav) built in and the system just died. Now I have poked around and found 3 diodes faulty. They are surface mount devices rectangular in shape with what can see being band or line followed by 3583??? Can anyone help please as to what device it is. 🤔
Conventional Current - early scientists got it the wrong way round, but like those who still believe the earth and mankind are only 6000 years old, they couldn't be bothered to change their mind in the face of obvious proof otherwise 😉
Diode is in power banks to refresh the battery, and is memory effected by default, to avoid the refresh. After several perfect charges and proper discharges (requires 1.4 A phone such as Samsung or Lenovo), the memory effect leaves the diode, and the battery refresh happens the battery becomes stronger. Satellites receive signal from the power bank, and decide whether the user has the right to use the modified device or not. If not, they disable its inverter, and locks down the charging.
I realize English is not your first language, but that makes no sense whatsoever. Diodes do not have any "memory effect." I have no idea what you are talking about with regard to "Satellites."
you barely touch zeners and omit leds completely, both of which can pose a diagnostic challenge to novices, and yet somehow manage to match video run time to capacitors (which are far more complex topic). perhaps a segment explaining p-n junction, its variants and typical characteristics would be time better spent than in depth study of basic application cases. good tips on bat54, tho the issue is not exclusive to that particular type - if a diode comes in smd package it likely has analogous layout variants
Sometimes I think I am justified in believing people don't always watch the video before commenting: at 1:44 for 19 seconds I discuss the scope of this tutorial video and I hoped it was clear I'm going to present Zeners, LEDs (and some others variations I mention) on their own videos though I only inferred that rather than specifically saying so. Yeah sorry this one got a bit longer than I intended, point taken. Like you say there are similar SMD types to BAT54, I'm pleased to see you found it a good example though, it is the most common type I have come across so far on GPUs and motherboards
Your polarity drawing on full rectifier is misleading. You should not draw half waves as an explanation of negative polarity. Half wave represents voltage. There is none negative voltage at same time when there is positive voltage on other end.
@Yama 007 Yeah it was a bit iffy and I had to add some subtitles as I also messed it up a bit. As to whether there is any negative voltage depends on your point of reference - but I accept what you are saying 😉
@@LearnElectronicsRepair Well... when you start mentioning point of reference you should also explain 0V ;-) I prefer drawings using 0V. This way usually people immediately recognize difference between - and 0V. Which is what AC is about.
I have spent several years learning electronics watching UA-cam videos and I must say that you are the best teacher I have seen. Every time I watch your videos I learn something new and gain very important information to really grasp how components work in a circuit. Thank you for explaining things so well. You are the best my friend.
1 minute 30 seconds in and my mind has been blown. The amount of connections you have allowed me to make with your guidance and you make these videos for free. Hats off to you sir and much respect/admiration/gratitude sent over from across the pond! Thank you so much!
You are a true blessing to the YT community. I came to electronics later in life but through your tutelage have learned to diagnose and repair so may items that I find thrown away. I now have quite a collection of old appliances that work good as new and are no longer going to end up on landfills or fire pits.
I cannot truly express how much I appreciate all the wisdom you share. You have an amazing gift, Thank you!
Outstanding stuff, even if you know electronics already this is a good refresher !
What an exellent teacher. I have watched dozens of repair videos, even your 2 hour GFX one. Trying to get a grasp on the numbers. I feel with this I actually understand. Thank you.
Great Stuff Rich, teaching future generations and refreshing us old goats. Thanks mate.
I have been watching how to videos for the last several years and it’s finally starting to click. Thanks for taking the time and explaining it well. I’ll keep watching until it all makes sense!
I'm so glad I found your channel. You've helped brush up on stuff I've forgotten since I started learning this at age 8. I'm nearly 43 so that's the vast majority of my life. I was told by plenty of seasoned techs that you always forget more than you remember as you become specialized. That's why it's so important to keep learning. Fun fact: I ended up arguing with a PhD-EE who had forgotten how capacitor discharge time-constants work. He thought the curve was more like a battery than the sharp drop it is and screwed up integrity of the sensors; +-60g crash data recorder g-force sensors. Liability much? "Oh it's okay. The NASCAR driver only sustained 8g in the crash." There was a +-6g primary g-force sensor set, but Chernobyl already shows what having sensors (Geiger counters, in that case) that top out far too low for the environment you're in can do. I took this as a strong warning to never rest on my laurels. To paraphrase Ferris Bueller: "If I'm going to get shown-up, it's not going to be by a guy like _that_."
Rich, you are an outstanding teacher of electronics. I learn more from watching your videos than anywhere else. you give just the right information and manage to distil all the more important parts. Well done my friend, there are few people who can do this really well.
Their is always something new to I learn when I see your vids again and again. Thank you dear Richard and the whole technological platform.
Thanks again for these excellent refreshers! Darrell - 🇨🇦
You're welcome. Refreshers to some and new material for others 🙂
Thank you for another video.. I wish to learn as much as I can from you
Best explanation of diodes on youtube i think ! thanks Richard ❤
These are the best electronics videos ever.
Fantastic video! I can not believe how fortunate I am to have watched this video - answered everything I wanted to know!! Thank you very much!!!!
Just subscribed, outstanding teacher.
On unmarked bridge rectifiers the clipped corner also denotes the positive output.
Thanks, this is propper in depth. I have been trying to learn diode replacements for donks
Really useful....thanks, Rich.
Glad to see the teacher back once again a bit long but very informative thank you for your time and knowledge it is much appreciated.
You are very welcome
so glad you redid this video
The only practical applied electronics videos that I can follow. Tried for years to find the more applied part of the field not the overloaded textbook slide show. Like in cooking I just want to make a couple recipes and have a bit of fun enjoy my time, and in electronics I just want to learn and fix stuff that others would just throw away. Thank you sir, how do I send you money??
Thanks again for your Knowledge
Season greetings. I understand so much from you since the past day I ran into your video. 🙏 👍
Great series, looking forward to the next one
Coming soon!
Thanks for the complete explanation. Many many of my questions have been answered here.
A thorough master class.
Very informative..Thank you.
I graduated electronics in 80s.
Splendid content!
Best Diode video ever. Thank you
Wow, thanks!
I loved this. Especially on how to test in diode mode on my MM. I didn't understand how switching the leads made a difference. I do now.
congratulations for your knowledge, especially for how you share it. You have a naturalness in explaining that makes everything simple and clear. Listening to you is very pleasant, congratulations for the knowledge you give to those who want to enter this fantastic world of electronics
Perfect explainations ! Big thanks
Nice episode to the series Richard and many thanks for the upload.
Very welcome
Good job, sir! I pick up knowledge from all your videos.
Great video for anyone starting electronics and also a useful refresher for those that know a bit more.
Regarding rectifies, there were also ones made from copper oxide. They looked like a stack of washers with fins.
Finally, when selenium rectifies fail, they can produce an unspeakably foul smell!
Fantastic video thanks 😊
Great informative video, thanks as always for sharing :)
My pleasure!
Great refresher information in the video. I am not a newbie to electronics, but I appreciate your approach to introducing diodes. Great examples. You earned a like and a subscriber. Thank you for taking the time to make these videos.
Very interesting, thanks!!! Subscribed.
Really enjoying this series of videos! Thanks so much for taking the time to make these. One question I have is between 22:29 and 24:45 where you talk about the diode that helps short out the spike in voltage when the relay turns off, why isn’t at least some of the voltage directed towards ground via the transistor?
2:11 - Can you discuss the PIN diode?
Thanks for the tutorial on diodes, a lot good info in this video. I feel like I learned something. Min split heat pumps have become common for heating and cooling. They have a bridge rectifier and its nice to know how I can test it. Funny thing, they call those units "inverters" but thats converting from DC to AC right? Still haven't learned why they call them that. Anyway, great tutorial. Take care.
Thank you so much!
This is so well explained
Thank You So Much!
Thank you very much that was very informative and detailed
Thank you Richard
so amazing video so much you can learn insane! Respect!
thank you for sharing this, is a great effort, and really appreciate!
You're very welcome!
Dear sir , you forgot the use of diodes to the voltage regulators (LM317 or LM7805 ..etc) to boost the output voltage..!!! Very very useful in electronics..!! Thank you for your time.
You Blimey's sure know how to explain something! I follow Rickey Comiskey on YT and have great respect for him! Thanks for your generosity!
Great video. Thanks a lot!
Glad you liked it!
Hi. Thank you for shearing. How about crystal radio with galena? 😄
Great explanation I've come across in my two years of blowing stuff up perhaps I'll start mending something now ,😜👍
great video mate! thanks a ton.👍👍
Hello Rich , I am confused with the current flow , - to + , backwards so diodes and transistors I just don’t completely understand , I like your videos , thanks for shearing your knowledge , regards
Another great video in the series. When are you doing one on Transistors please?
My understanding about the diode schematic symbol is that back in the day. Current was believed to flow from positive to negative. So when the symbol was created the arrow was meant to show the direction that current could flow. Later, when it was discovered that current flows from negative to positive. The symbol was never changed to reflect this new understanding. In college, my professor taught me to think of it this way "the arrow is a car driving into a brick wall". Meaning, current can't flow in that direction. When using a diode for reverse polarity protection. Schematics have always shown the symbol with the back of the arrow towards the positive of a battery or other DC power source. This positive and negative confusion also affects the general public as well as novices when it comes to things like car batteries. As they assume positive means more of something and negative as less. So more must flow to less in order to equal out. But it is actually based on the words used to name the charge states of electrons and protons. Electrons being considered to have a negative charge and protons a positive charge. As we know today, electrons move through wires but protons do not. So negative represents the charge of the electrons that are moving through the circuit.
It’s called the conventional current direction. Conventionally it is still accepted that current flows from positive to negative/ground.
You put it very well! I am actually going to send this to my two sons (one an electrician and the other an IT guy). I hope you do not mind? Regards
A car driving into a brick wall. That's as easy to remember as transistors. ie NPN = Not Pointing iN and PNP = Pointing iN, Punk.
I am still confused about this , help me understand , flow from - to + , PNP and NPN transistors 😵💫
You can also show a rectifier as used in linear power supply, that has 2 diodes connected to a center tapped secondary,
and showing/measuring HV diodes such as those used in a microwave oven, as well.
I'm new on your channel, just suscribed and enjoying your videos. Great content here Richard! Greetings.
Welcome aboard!
Thanks
Great stuff! Happy to support your work on patreon. Even though my support is small I'm still hoping that it will at least little bit help you to continue with your excellent work.
Every little bit of support helps - thank you 😀
Thank you. Did you ever go to Johnny Birketts (Lincoln).
48:10 "... and if stayed awake you'll know it's a shcottky diode" LOL
Great presentation.
Thank you.
You missed zener diodes and how to test them especially reverse voltage rating (in the case of no marking to identify it).
Now now.... The first thing I said at the start of this video, is that it was only going to cover rectifier diodes
Zener diodes is here
ua-cam.com/video/trjbHhLERic/v-deo.html
Enjoy
@@LearnElectronicsRepair
I did watch that video and I watched it again. Great stuff!!
I would like you to address identifying defective zener rating in circuit especially when schematic circuit is not available.
Much appreciated!
would love to see a video on "All You Need To Know About Schottky diodes to fix stuff"
I've got a question about an oscilloscope a neighbor recently gave me. It is an old Phillips 25 megaherz 2 channel model. The power cord is only two terminal with no earth ground pin. Does this mean that this unit is isolated (as in a linear isolated PS) and safe to use without the use of an isolation transformer? Thanks and I do enjoy your videos.
The forward voltage of schottky diodes in power circuits is rarely less than about half a volt and can be higher at typical working currents.
informative
I just fixed an inverter and I could not believe the diode tested correctly with meter but when in circuit it dropped 8volts of a 12v supply. Never seen it before and doubted everything I knew about diodes. Replaced and all ok.
Nice one. I haven't seen that kind of failure myself
In German the connections are called Anode and Kathode. Makes up for an easy mnemonic trick, which half works in English as well. First the multilanguage one.
With the top half of the A of Anode you form the triangle part of the diode.
And with the K of Kathode you can imagine forming the line and the top part of the triangle.
This way you can easily figure out which is which. 🤗
If you flip the diagram so that the bar is on top, you can view the triangle as kind of an A(node) with a C(athode)ross bar that became floaty and ended up on top. I just invented this memory aid. Feel free to use it as you please.
Hello Richard, can you tell me how to know white smd LED chip working voltage? If voltage drop use diode test mode show 2.5v. Can it be the working voltage of led is 3 volt? And not 6v or 9v
LEDs require a constant current supply. You can use 3V 6V or 9V supply but you must put a resistor in series with the LED to limit the current, or for higher power LEDs use something like LM317 voltage regulator wired as a constant current source
lednique.com/power-supplies/lm317-constant-current-power-supply/
Thanks you so much. So if i use adjustable power supply, i am not should use resistor right? I just should increase the current from the smaller right?
@@unintendedperson For a constant current supply you just need to add in a series resistor to drop 1.25 V at the required current.
any chance you could change your mobile phone alert notification sound? I'm using the same sound and every time I watch your video you get a message and I think it's my phone going off, I go to check and nothing :(
looking for days trying to find the voltage on a dell xcr8d 0v62h atx 8 plug 240 w power supply.
when checking the purple wire i have 12v and mobo not starting
is that a dell standard or should it be 5.5v replaced with new 255w psu still 12v, any ideas
It sounds strange they would change the ATX standard, and use 12V Standby on the purple wire, but who knows if they are making proprietary PSU and Motherboards with unusual connectors. Are you saying the PSU does not have the normal 24pin ATX connector?
Hi 👋🏾 I have an factory fitted infotainment system in the car (radio,bluetooth and satnav) built in and the system just died. Now I have poked around and found 3 diodes faulty. They are surface mount devices rectangular in shape with what can see being band or line followed by 3583??? Can anyone help please as to what device it is. 🤔
Say a few words about how or why a lightning flash will wipe out a row of power diodes… Thank you❤
Can you explained better how de bridge diode rectificater works ? The 4 diods ? I don't understand ... Thanks 🙏 ...
Try my explanation again of how the bridge rectifier works at 25:00
Did that help or is it still confusing?
If electrons flow from negative to positive , how does a diode flow from positive to negative ?
Conventional Current - early scientists got it the wrong way round, but like those who still believe the earth and mankind are only 6000 years old, they couldn't be bothered to change their mind in the face of obvious proof otherwise 😉
Study semiconductor / transistor composition
There is a lot of information concerning atomic structure and how it interacts with electricity.
Diode is in power banks to refresh the battery, and is memory effected by default, to avoid the refresh. After several perfect charges and proper discharges (requires 1.4 A phone such as Samsung or Lenovo), the memory effect leaves the diode, and the battery refresh happens the battery becomes stronger. Satellites receive signal from the power bank, and decide whether the user has the right to use the modified device or not. If not, they disable its inverter, and locks down the charging.
I realize English is not your first language, but that makes no sense whatsoever. Diodes do not have any "memory effect."
I have no idea what you are talking about with regard to "Satellites."
💪
Yeah
you barely touch zeners and omit leds completely, both of which can pose a diagnostic challenge to novices, and yet somehow manage to match video run time to capacitors (which are far more complex topic). perhaps a segment explaining p-n junction, its variants and typical characteristics would be time better spent than in depth study of basic application cases. good tips on bat54, tho the issue is not exclusive to that particular type - if a diode comes in smd package it likely has analogous layout variants
Sometimes I think I am justified in believing people don't always watch the video before commenting: at 1:44 for 19 seconds I discuss the scope of this tutorial video and I hoped it was clear I'm going to present Zeners, LEDs (and some others variations I mention) on their own videos though I only inferred that rather than specifically saying so. Yeah sorry this one got a bit longer than I intended, point taken. Like you say there are similar SMD types to BAT54, I'm pleased to see you found it a good example though, it is the most common type I have come across so far on GPUs and motherboards
Here's a noob question. Why weren't diodes called electrical valves? Or capacitors called energy reservoirs?
Sorry, typo... Shotlky.
kindly write in big form letters i couldnt see you wrote up
German inventor Schottky so just read as you did - the same sound like shoes .
Your polarity drawing on full rectifier is misleading. You should not draw half waves as an explanation of negative polarity. Half wave represents voltage. There is none negative voltage at same time when there is positive voltage on other end.
@Yama 007 Yeah it was a bit iffy and I had to add some subtitles as I also messed it up a bit. As to whether there is any negative voltage depends on your point of reference - but I accept what you are saying 😉
@@LearnElectronicsRepair Well... when you start mentioning point of reference you should also explain 0V ;-) I prefer drawings using 0V. This way usually people immediately recognize difference between - and 0V. Which is what AC is about.
Just asked a Pole how to pronounce Shotky... apparently, he was German.
Walter Schottky was born in Switzerland but worked mostly in Germany for Siemens co-developed the ribbon microphone and speakers
Your videos are dark.