All You Need To KNOW About SCR Thyristors (Traics and Diacs) To FIX Stuff! How They work tutorial

LER #350 Let's take a look at Thyristors, otherwise known as SCR, and closely related semiconductor devices Triacs and Diacs from the point of view of a repair technician. These fairly common components are often misunderstood so let's clear the fog and learn all you need to know about Thyristors and their closely related cousins to fix stuff!
If you would like to see how to check a Thyristor or Triac has gate drive using a multimeter, check out this short video • These Christmas Lights...
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Thank you
Richard

[@Elfnetdesigns]

The main place I see TRIACs used is in SSRs (Solid State Relay Circuits) be it an actual standalone SSR module or an SSR circuit "embedded" on a board as part of the whole circuit. One word of caution I have about SSR modules namely the cheap ones off ebay (Fotek, etc) is that usually they are labeled wrong like say a 40 amp will actually be a 10 amp but can handle a 40 amp spike but run constant on 10 amps. This is fine for inductive loads like an HVAC compressor, but can be a problem on resistive loads like a heater element.

[@kurt9232]

The best explanation i´ve ever seen! Thank you very much! Helped a lot!😊

[@leibfriedwolfgang9155]

Thanks a lot for correct explained ❤ Sometimes I have problem with the British accent! What I missed is directly connected diac and thyristor to Gate! Variable supply of diac to Gate! But thanks 😊 U give me Manny answer's and open a lot of questions!

[@uquarosh]

Good topic choice today. Lots of misconceptions regarding triacs and diacs etc. All soundly explained. Thanks.

[@allenpaley]

I've been on a week-long knowledge quest for information on the ins and outs of thyristors, and this video has been the best and most illuminating of all the ones I've seen so far. Your material is very easy to follow, and very practical. With gratitude I would like to encourage you to keep doing what you're doing. Whether or not your donated labours feel fruitful so far, you're establishing a great body of work, and you'll have earned a legacy when it's all said and done.

[@tonylayfield8750]

Bravo. An awesome explanation (as always). Here's hoping & trusting for many more of your excellent educational & informative videos in 2023.

[@BlackOpsJuJu]

I had a Basic understanding of triacs but this has really cleared things up Thanks for sharing Great Vid as Always Cheers

[@CMarxChako]

39:51 🤣🤣🤣🤣🤣 "...it ain't safe for fingers...," understood. I learnt about these in college electronics but never got the concept until now. It was the "finger" warning that opened up my fingers 😳 I mean mind, opened up my mind.. 😓

[@it-sd]

I’m a huge fan of you’re All You Need to Know About videos. Thanks for going to all of the effort-I always learn a tonne. Happy New Year!

[@KB1UIF]

Hi Rich, in your diagrams of SCR''s the opto isolators when turned on will actually be turning off the SCR's and the loads. It will control the SCR but the logic is reversed, opto on load off. So an additional resistor would be required to turn on the SCR like your earlier diagrams that were using switches.

[@techquirks707]

Your videos are always top class. Thank you.

[@LearnElectronicsRepair]

Thank you for your support, it is much appreciated

[@seeithappen1]

Made a power supply once with a Thyristor chopping the 220V and feed the pieces to a capacitor. Is fun to see this on a scope.

[@sretchko]

Thanks for all your great videos! Your crocodile clips look just like my alligator clips :)

[@gimi3428]

A very happy new year Richard and thanks for the effort with these very amazing videos you upload on here. Happy new year to every one on here 👍👍👍

[@olegserov6779]

Great job. Thank you very much. But you've mixed up Zener diod with Shockley diod (Dinistor). Diac is originally two Shockley diods counter-axial connected. There's a difference in V-I characteristics of Zener diod and Shockley diod. The main difference is that the Shockley diod is a thyristor controlled by a threshold voltage.

[@davidgrey943]

Thanks for a very helpful video it helped clear up some things I did not quite understand about the characteristics of both SCRs and Triacs.

[@cougar1861]

Yes, it was an hour well invested. Thanks.

[@Gonzi-ze1sk]

I've been watching your videos, and they're helping me big time to grasp electronics on a deeper level. My effort is paying off, and I'm really getting the hang of it. Thanks for making such awesome content and sharing your knowledge.

[@ibrahimbhatti9342]

The video is much informative. I highly appreciate sir...

[@janakapriyadarshana5835]

Another Superb explanation of theory with practical scenarios..., Happy new year.....

[@markbaker594]

Hi Richard, this is completely off topic, so please forgive me. There is a tool called CMIZpper from a guy called Harald, I think he is in Holland, have a look at his site, reason being some of his diagnostic tools could come in handy, especially the ones which report voltages as soon as the machine is turnd on, it plugs into the usb pot, also shows if CPU is running. To be fair, you may already get this info type from your current cards, but have a look all the same. His tools are Used by a guy called Paul Daniels in Australia who fixes Macbooks (No he's not magician ;-)) He also has his own Flexboard program, you might want to take a look at that as it comes highly recommended. I am not affiliated with any of the two guys; just thought it might be a couple of things to add to your arsenal!! Best regards Mark

[@Nada-ff5qy]

Thank you

[@synthpest6731]

Love these videos you do. I'm 50 with a 50 year old brain, I know nothing about electronics and most of the videos I look at are too intense but I find your descriptions and explanations suit my way of learning. I think if I looked at a college course it would fry my brain

[@davestake44]

Awesome video I am learning a boat load of stuff I would not have out of a book . Thanks

[@robwebster7406]

Thanks for vid, I have learned a bit more on ground and hot ground which was confusing me a bit before 👍

[@daz41262010]

happy new year Richard :) great explanations :)

[@nasosst3092]

Happy new year dear. Hope next year's videos will be full of self sarcasm. Thanks from a convinced fellow atheist.

[@pdrg]

Half way through the video and have to go home - this is a great lesson, nicely put, and clears up a bunch or questions I've had hanging for decades. Great work, thank you.

[@RanDavies]

Thanks

[@LearnElectronicsRepair]

Thank you very much Ran, that is really appreciated

[@RanDavies]

@@LearnElectronicsRepair you're welcome. It's a small price to pay for what I've been learning from you... thank you!

[@anthonyselby8337]

Happy new year and thanks for the videos they have been a fantastic help learning electronics which leads me to my question Could you cover how to make and use the control circuits to use with the scr to detect the ac and chop it Thanks

[@Lightrunner.]

Happy New Year ,, i wish..... 🥳🥳 Ohh , there is a fault at 28:40. The gate of the thyristor must be positive. Greets from Germany🤗🤗

[@LearnElectronicsRepair]

Yeah I forgot to add the pull up resistor on the photo transistor collector, then when the controller turns the LED on the thyristor turns off, and vice versa. Well spotted 🙂

[@Lightrunner.]

@@LearnElectronicsRepair iam learning every day.

[@reacey]

Happy new year Richard

[@Dutch-linux]

triacs are great to make a light organ i have made a few 3 channel that reacts on music you just need a few resistors a few capacitors and a 1:2 minature transformer you make basically 3 filters that react on bass mid and high .. i am sure you could make something like that with the parts you have handy and that shows the switching effects that triacs have

[@davidcross30]

Great video as ever. Could you show some of the ways to drive these (going from dc to ac) in real equipment?

[@robtitheridge9708]

Its hard to believ the head aches that SCRs caused in the late 60s early 70s when they started to be used in the psu of tv sets (bush T20 anyone) just got are head round them and good old SONY came up with there own version the gate controled switch used in psu and line output stage. Mind you they were easy compaired to thorn and there series switch mode psu

[@LearnElectronicsRepair]

Hi Rob - I do remember the 'chopper' circuits used on old TV power supplies, and then distinctly recall being taught about the SYCLOPS circuit and that was also my first introduction to hot ground, before then the chassis was always connected to neutral though you needed to check the mains plug wiring just to be sure There was a myth going round that once you plugged in one of these new fangled SYCLOPS TVs in and it started it up, you could then unplug the mains and it would keep on going, seeing as it was self powered 😁

[@davet3804]

Heat shrink on BNC for safety?? Happy new year We really appreciate your work 👍👍

[@BjornV78]

0:43 You have also Sidac's

[@lattehour]

26:35 i am afraid you are somehow wrong here (in a way) Today many appliances have the uC are operated directly on the mains usually using an offline switcher like tiny270 or LNK304PN in a forward converter topology where the secondary(just a single one ) after rectification is directly tied to the Mains Line 240V , the uC is now able to operate the triac by allowing it to complete the loop through the uC and then through the triac this is one note application_note/an440-triac-control-with-a-microcontroller-powered-from-a-positive-supply-stmicroelectronics.pdf this is another Philippe RABIER/Laurent PERIER APPLICATION NOTE MICROCONTROLLER AND TRIACS ON THE 110/240V MAINS if you want i can send you an schematic of such application and you can make a in depth video

[@nerdylicious1814]

Im building a coil gun the thyristor false triggers when charging capacitors, I dont know why help would be appreciated

[@alanwake5927]

@38:40 what you mean that the 5v are floating

[@1pcfred]

That was a good nap. I miss anything?

[@user-kc9rp4cm6g]

what abut IGBT

[@biafrafetech1580]

Hello Sir, can I make a 12v dc inverter using a TRIAC instead of a MOSFET or Transistor..

[@analoghardwaretops3976]

Sure you can ... BUT... You're going into prehistoric times... Like using steam engines for locomotion on trains & ships... When everyone else is using Electricity for Maglev. trains& nuclear fuel for ships & spacecraft...

[@sptuuri]

Captions would help a hearing impaired person like me.

[@unintendedperson]

First 2023

[@seeithappen1]

Still 2022 at the moment of this writing ...

[@unintendedperson]

@@seeithappen1 first comment 2023 from my country

[@Lightrunner.]

In moment it is 2022🫣. T- 2 hours

[@LearnElectronicsRepair]

Happy new year to all of you 🙂 Now let's get a few of those religious types around who predict that god is going to end the world at midnight, and have a really fun discussion about how that would logically happen, would the destruction of the world start somewhere in the Pacific at midnight and work it's way round, presumably suddenly jumping 15 degrees westwards every hour so everyone gets destroyed at the ordained time in their region (with extra consideration for bordering countries such as Portugal/Spain that have a different time zone but are in some parts at the same longitude) , and what method would god use to prevent the rest of the planet ending and keeping it viable once a segment of it had been destroyed otherwise some people would be killed too soon by up 23 hours. And what would happen to someone who happened to be at the north or south pole, because there are no time zones at the poles so presumably they would either have a justifiable case to avoid Armageddon altogether or be able to choose their own time of destruction thus overriding gods will. Then of course if it is just the human race being destroyed and not the planet/biosphere, if you were to fly westward in a plane fast enough then you could land in the newly emptied time zones thus avoiding your fate altogether.

[@seeithappen1]

@@LearnElectronicsRepair One day man will celebrate new years eve on the moon .... There is a planned moon landing in 2024