Are there triacs whose RMS IT > 59A? - Page 1
Forum section: electronics / projects

author: KerimF
author_rank: Frequent Contributor
timestamp: October 30, 2024, 10:06:40 am
content: Locally, I may find 40A triacs (Vpeak > 600V).On the internet, I noticed that 40A seems to be the highest current rating for many triac manufacturers/distributors.I wonder if some of you had the chance to know a certain company which produces/sells power triacs (for 60A to 100A).

author: Roehrenonkel
author_rank: Frequent Contributor
timestamp: October 30, 2024, 10:31:28 am
content: Hi KerimF,have a look at:https://www.semikron-danfoss.com/de/innovation-technologie/siliziumkarbid-leistungsmodule.html

author: moffy
author_rank: Super Contributor
timestamp: October 30, 2024, 10:39:34 am
content: Higher currents tend to be SCRs, you could always use a parallel/inverted pair of SCRs.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 30, 2024, 05:41:50 pm
content: Quote from: moffy on October 30, 2024, 10:39:34 amYou are totally right in case the product needs one or two triacs, not 12

author: KerimF
author_rank: Frequent Contributor
timestamp: October 30, 2024, 05:51:23 pm
content: Quote from: Roehrenonkel on October 30, 2024, 10:31:28 amThank you for the link.In their English site, there is no mention of the word ‘triac’. They have power SCRs instead (Thyristors).

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 30, 2024, 06:18:55 pm
content: Ixys manufactures some very high powered Triacs.For instance, the MCMA650MT1400NKD is rated at 300A and 1400VThus I would start my search on their website.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 30, 2024, 06:27:05 pm
content: Quote from: schmitt trigger on October 30, 2024, 06:18:55 pmThank you, I will.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 30, 2024, 07:09:00 pm
content: Quote from: schmitt trigger on October 30, 2024, 06:18:55 pmFor instance Ixys moved to littelfuse.com.Unfortunately, searching their pages for a power triac is not easy, unless I miss something to do.Apparently, they have triacs rated for currents higher than 40A. But after downloading their datasheets, I found out that their ratings are for 40A or less (not 88A or 66A as their reference says!)And, in the case of higher currents, it turned out they are not triacs but 2-SCR modules instead (having two gates).

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 30, 2024, 10:18:21 pm
content: Quote from: KerimF on October 30, 2024, 07:09:00 pmSee :https://www.littelfuse.com/products/power-semiconductors/thyristor-modules/ac-switches/ac-switches-triacs.aspxthat covers 35-650AYes, 2-SCR modules are common for more rugged and even higher power designs.https://www.littelfuse.com/products/power-semiconductors/thyristor-modules/single-and-dual-thyristors/dual-thyristors.aspx

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 05:06:34 am
content: Quote from: PCB.Wiz on October 30, 2024, 10:18:21 pmI visited already this page.The PDF datasheets of VW2X60-12IO1 (60A), VW2X60-14IO1 (60A) and VW2X60-16IO1 (60A) are damaged (cannot be read).MMO110-14IO7 (112A) and MMO140-12IO7 (130A) which are supposed to be triacs, they are 2-SCR modules.I didn't try downloading the datasheets of higher current ratings.

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 09:13:52 am
content: https://www.semikron-danfoss.com/products/product-classes/thyristordiode-modules/detail/skkq-560-0889010008890105.htmlwhy are you having so much trouble searching for a bog standard power module??These are utterly standard power modules used in industrial applications.. further the current rating you posted is a little more than a piddly pissant module..The above link is a 560 A triac module from Semikron that@Roehrenonkelposted yesterday.. 10 times the rating you are looking for..I found this in under 2 minutes.. I m sure if you had a little more patience you will find a appropriate module for your application..Not just Semikron, you have such standard module from Fuji, Mitsubishi, IXYS and many other reputable manufacturers..Either you are expecting us to search for you or looking for a reason to rant about why manufacturers dont make it easy for you specifically to search for stuff.. or both...PS: A triac is literally a pair of antiparallel thyristor modules... if you are not aware of that... you should not be playing with such high current devices...make no mistake... they will kill you..

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 09:24:30 am
content: https://www.semikron-danfoss.com/products/product-classes/thyristordiode-modules/detail/skkt-172-078941500789416007894170.htmlTo be even more clear... this is a dual scr module... you can literally create a triac by shorting the either ends and then using the shorted ends as MT1 and the center connection as MT2..This is a 175A module... more than the 59A you require...I dont understand what is so hard about searching or having the patience to search...I have literally given you two examples of ready modules for triacs or how you can make your own triacs from thyristors... and it took all of 5 minutes...

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 01:27:34 pm
content: Quote from: krish2487 on October 31, 2024, 09:13:52 amHi Krish,Let us first clear the misunderstanding.In year 1975, I started my private business using triacs to control AC bulbs (220V, 50Hz) on outdoor panels. Then, on request, I did indoor various light controllers for dancing clubs and the like. In 1980, I produced the first outdoor moving message (for English and Arabic texts) using a triac for every pixel (25W/220V). Since then, triacs were the main components of most of my products till the filament bulbs were replaced by LEDs. In my most actual light controllers, N_MOSFETs replaced triacs.A triac is triggered, in both half cycles, by drivingone gate only.As you know, 2-SCR module has two separate gates.I mean, if I don't mind complicating the controller for 12 triacs by using 24 SCRs, I wouldn't start this thread in the first place.Truth be said, I wasn't expecting a positive reply as I mentioned on my first post.And so far, it seems that the highest rating of a commercial triac is 40A.I hope you agree that Semikron doesn't produce triacs (Reply #4).And littelfuse.com doesn't produce triacs whose rating higher than 40A (Reply #7)In brief, if I want to switch high AC currents by driving two gates, I had no reason to start this thread.Kerim

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 01:36:01 pm
content: Quote from: KerimF on October 31, 2024, 05:06:34 amI can't confirm that; all three datasheets look fine. Maybe there is/was a technical problem on your end, either with the internet connection or the PDF viewer?

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 01:37:58 pm
content: Quote from: KerimF on October 31, 2024, 01:27:34 pmAnd whats preventing you from driving both the scr gates with the same signal when configured as a triac i.e antiparallel configuration??Was I not clear in my first post?? Internally a triac is doing the same thing for you... two scrs in anti parallel configuration with the gates commoned and driven... you still end up with one drive signal.. two main terminals..But then if you were working with SCRs since 1975 you should be knowing all this already.. this is not anything new.. this is how it always has been.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 02:30:16 pm
content: Quote from: krish2487 on October 31, 2024, 01:37:58 pmI guess you know that an SCR has the three terminals K A G. The driving pulse enters G and returns from K. And GK is equivalent to a diode (this can be checked by a diode tester). I mean V(G,K) is about 1V; relatively very small if compared to V(A,K).Let us see what will happen if we connect the two gates of an SCR antiparallel configuration. Now we have node(K1,A2) , node(G1,G2) , node(K2,A1), that is three terminals.During the first half cycle, the triggering pulse will enter the node(G1,G2) and has to return from node(K1,A2).During the second half cycle, the triggering pulse will also enter the node(G1,G2) but has to return from node(K2,A1) which is impossible, unless the triggering pulse has two isolated references. Actually, there must be two isolated drivers, one for each SCR.Naturally, I also produced many industrial power controllers (for welding, for example). And I had to isolate the SCR drivers by a small transformer or optocoupler.Added:I will be very surprised if any reader has a reference of a circuit that drives 2-SCR module by 3 lines only!!!

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 02:47:34 pm
content: Quote from: ebastler on October 31, 2024, 01:36:01 pmGood to know they are fine on your side. Are their PDF sizes big? Perhaps you can help me see one of them.

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 02:51:45 pm
content: Quote from: KerimF on October 31, 2024, 02:47:34 pmHere's a sample attached.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:03:28 pm
content: Quote from: ebastler on October 31, 2024, 02:51:45 pmIt seems my Adobe Reader 9 (9.1.0) is now very old to some new PDFs, as the one you uploaded.Unfortunately, I don't have the privilege to update it.Thank you, anyway.

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 31, 2024, 03:08:17 pm
content: Quote from: KerimF on October 31, 2024, 02:30:16 pmIf you’re willing to use an opto coupler it can be done.Image from General Electric’s SCR Manual, 5th edition.Replace the reed relay with a Triac opto coupler.I have used it. It works.

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 03:11:50 pm
content: Quote from: KerimF on October 31, 2024, 03:03:28 pmIndeed. Acrobat Reader 9 was released in 2009. Whichever organisation runs your computer, you really should lobby for a current version.Doesn't your web browser provide a built-in PDF viewer?

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:30:13 pm
content: Quote from: ebastler on October 31, 2024, 03:11:50 pmI am an independent engineer since after graduation (about 50 years ago). This is why I have no privileges about many things, mainly since year 2011, due to world's regulations. So, I used to live with what I have. (Perhaps I am somehow weird for insisting to always own my time and will at any cost.)If I remember well, my browser provides a built-in PDF viewer which I disabled. My internet speed is, in general, slow. So, I chose to download files instead of viewing then downloading them.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:37:58 pm
content: Quote from: schmitt trigger on October 31, 2024, 03:08:17 pmNow I have to see what a THYRECTOR is

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:43:23 pm
content: Quote from: KerimF on October 31, 2024, 02:30:16 pmhttps://www.bristolwatch.com/ele3/1d.htmor if you are up for it.. pulse transformers which provide the necessary galvanic isolation. connect winding end of the transformer to one of the main terminal and the other to the commoned gates.. it does not matter which main terminal you use.. they work the same... one scr works in one half cycle.

author: Siwastaja
author_rank: Super Contributor
timestamp: October 31, 2024, 03:44:33 pm
content: I'm not buying the indirect claim of you not being "privileged" to download a PDF reader, if you can access this forum. Do you want solutions to your problems, or do you just want to come up with excuses for why you can't deliver? For the latter, this forum isn't a very good place.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:53:40 pm
content: Quote from: schmitt trigger on October 31, 2024, 03:08:17 pmI recall I used it for an industrial power application once. It worked well when it was tested with resistive loads. But with a heavy inductive one, things went wrong (fortunately the power SCRs were not damaged). I solved the problem by using a small transformer with two similar secondaries, one for each SCR.

author: schmitt trigger
author_rank: Super Contributor
timestamp: October 31, 2024, 03:54:07 pm
content: A thyrector was an old equivalent for MOVs.But you don’t strictly require it for the circuit to work. It is there only for an optional protection.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 03:58:46 pm
content: Quote from: krish2487 on October 31, 2024, 03:43:23 pmSorry, I couldn't see thecommoned gateson any circuit! Did you?

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:10:40 pm
content: Quote from: KerimF on October 31, 2024, 03:58:46 pmNo… but I believe it was aimed at your comment of driving 2 scrs with 3 lines only… this circuit fits the description no…Now do you want to be pedantic or are you looking for a solution to your problem… if it is the latter… I have just given you a solution…

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:16:06 pm
content: Quote from: Siwastaja on October 31, 2024, 03:44:33 pmYou are fortunate you live where you are.For instance, this is the only universal technical forum I am allowed to join. All others, one after another, apologized for closing the doors to avoid breaking the rules.Anyway, most of those who live in different worlds (though all their worlds are all on the same planet, Earth) seem to have no idea what is real happening outside their world. This is sad, but no one can change it.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:20:51 pm
content: Quote from: krish2487 on October 31, 2024, 04:10:40 pmSorry, did I ask a solution for a problem?I just asked:"I wonder if some of you had the chance to know a certain company which produces/sells power triacs (for 60A to 100A)."It seems that Littelfuse has one for 60A but I am not sure if it is a triac or 2-SCR because I couldn't read their PDF.

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 04:35:17 pm
content: Quote from: KerimF on October 31, 2024, 03:30:13 pmSo, in a situation where your 2009-vintage standalone PDF reader is becoming useless -- have you considered re-enabling the browser's built-in viewer?Also there are PDF tools which are not developed in the US, and hence might be available to you under less strict sanctions. FreePDF from Softmaker is one example I am aware of; there likely are others. Have you looked into those?I can see Siwastaja's point here. "There is a part that might be suitable, but I can't read the PDF" does come across as a bit lame.

author: krish2487
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:49:00 pm
content: Quote from: KerimF on October 31, 2024, 04:20:51 pmThen you are on your own... me and many others have provided you with suitable engineering solutions and options available... if you want to strictly look for companies that make triacs in thetruest sense with current capacities greater than 60A... be my guest... and please do let us know here when you find one...

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:50:45 pm
content: Quote from: ebastler on October 31, 2024, 04:35:17 pmIf misunderstanding doesn't exist, most problems around the world won't exist too.Even in one family, real peace can hardly exist due to possible misunderstanding, once a while.For instance, about the 60A PDF, is it a triac or 2-SCR

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 04:59:36 pm
content: Quote from: krish2487 on October 31, 2024, 04:49:00 pmI recall someone (not here) said, many years ago, that he found such power triacs in China... Now, I doubt that such triacs (say for 100A) could be made in China and be reliable.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 05:15:44 pm
content: Quote from: ebastler on October 31, 2024, 04:35:17 pmhttp://www.freepdf.net/It has almost everything but PDF reader!

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 05:26:52 pm
content: This is the one I had mentioned. The manufacturer's site wants you to register; the second link is an independent download site (run by a renowned German print publishing house, apparently available in German only). Maybe one of them works for you?https://www.getfreepdf.com/en/downloadhttps://www.heise.de/download/product/softmaker-freepdf

author: ejeffrey
author_rank: Super Contributor
timestamp: October 31, 2024, 05:38:20 pm
content: Quote from: KerimF on October 31, 2024, 03:30:13 pmYou can also download PDFs and view them with your browser

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 05:52:40 pm
content: Quote from: ebastler on October 31, 2024, 05:26:52 pmThe first one just closed its door. It is not the first and will not be the lastThe second one is very good if I learnt German, at school, instead of French

author: Andy Chee
author_rank: Super Contributor
timestamp: October 31, 2024, 06:04:39 pm
content: https://www.foxit.com/pdf-reader/(be aware! Foxit attempts to install bloat in its default install configuration, so make sure you untick/uncheck the extras)

author: PCB.Wiz
author_rank: Super Contributor
timestamp: October 31, 2024, 06:36:16 pm
content: Quote from: KerimF on October 31, 2024, 01:27:34 pmNope. They might be rare, but they do exist.The 300A part already given in #5 is shown as a genuine three terminal triac, spec’s to 3 quadrants.SCR’s are a bit more complex to drive, needing two separate gates , but they usually offer higher surge ratings so designers take that, and gate drive is a tiny fraction of the cost of such high current designs.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 07:17:38 pm
content: Quote from: ejeffrey on October 31, 2024, 05:38:20 pmYou are totally right if I live by you.Why our lives have to be different? I am afraid it is about politics.For example, before year 1981, I used to order most of the electronic components, I needed, from Jameco (USA). Then, they apologized for not being allowed to accept more orders from me (I still miss their good service).I wonder if one can imagine to how far this trend evolved after 43 years.

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 07:28:45 pm
content: I realize that Syria is under heavy sanctions. In my understanding the US applies them most severely -- essentially affecting all products and services and the whole population, where other countries/regions limit sanctions to specific product classes or recipients.But you had mentioned earlier that your reason for disabling PDF viewing in your browser was that you wanted to save bandwidth, not that the viewer would not work. Hence ejeffrey's suggestion makes sense to me. Have you tried using the browser's built-in viewer? (It might also be outdated since updates have been blocked?)

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 07:42:36 pm
content: Quote from: Andy Chee on October 31, 2024, 06:04:39 pmThank you for the warning. But don't worryMy OS is also very old W7 (not W10 or W11), why?I bought my laptop in year 2010. After year 2011 (the start of the Arab Spring), I lost almost everything I had; a small farm by the city, a small house in it, a new Subaru car and all money I had. At that time, I thought it was better for me to die. But it happened that, despite all, I was able, while living in a very small apartment on the roof, to gain my daily bread and of my few assistants while getting more than this became luxury.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 07:49:48 pm
content: Quote from: ebastler on October 31, 2024, 07:28:45 pmA few years ago, I tried once to update it, I started having unexpected crashes. I simply restored the last good state of my laptop and it works fine since then.

author: KerimF
author_rank: Frequent Contributor
timestamp: October 31, 2024, 08:28:35 pm
content: Quote from: PCB.Wiz on October 31, 2024, 06:36:16 pmAfter reading your post, I returned to Littelfuse and downloaded MCMA650MT1400NKD. I didn't do it earlier because 300A is somehow overkill in my project that needs 12 triacs.At least, I know now that a triac for 300A does exist. Thank you.For instance, since early years, I used triacs in the second and third quadrants (gate current from T1 to gatenegative gate current).

author: ebastler
author_rank: Super Contributor
timestamp: October 31, 2024, 08:49:01 pm
content: You don't have to answer this, but I am honestly curious: If sourcing software and information is such a challenge due to the sanctions, how do you go about sourcing components? Now that you know that a component is available on the world market, can you just use it in a design?

author: KerimF
author_rank: Frequent Contributor
timestamp: November 01, 2024, 07:19:15 am
content: Quote from: ebastler on October 31, 2024, 08:49:01 pmGood question.Actually, the sanctions are applied on the ordinary people, not their high class, why? because this is how the world, by design, runs since always.I was asked to design a mains voltage stabilizer (10KVA, 50Hz) whose input may vary from 120V to 280V. And its output should be within 220V +/- 6V (or better). I did it by using 5 mechanical 100A relays (SPDT), plus one for protection in case of malfunction. But it turned out being not practical in case the input is not stable which lets the 5 relays be active (change their state) almost continuously; mainly if the maximum power of the mains line (as in rural regions) is close to 10KVA (if not less).When necessary, I partially solved this by software by increasing the output range up to +/- 15V. But I decided to stop producing this model unless I will be able to replace the SPDT relays with 2*5 power triacs (not 12 as I used to say, since I can keep the mechanical protecting relay).A retailer (who works for a local company of the high class) told me that he may be able to order for me such triacs when necessary. So, my first step was to find out if suitable triacs exist for this application. The second step will be to know if the new cost of the stabilizer (with triacs) can have a place in the local market. If it is ok, the third step will be to build a prototype using available medium power triacs, as BTA41.Meanwhile I keep producing simpler stabilizers, besides various DC-AC inverters, to survive.Yes, before year 2011, the prices of the imported raw materials were low while the imported ready-made products were relatively high. After year 2011, the situation was reversed gradually which let the local private businesses (not the companies of the high class) be paralyzed, one after another. Anyway, I am glad that my stewardship on earth will end sooner or later (at the death of my living flesh) and enjoy my last sleep and the non-stop dream (since there is no wake up to stop it) that will reflect in a way what I did in life.