Isolation of the RIGOL DS1054Z from the mains with two transformers  - Page 1
Forum section: electronics / projects

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 07:47:39 pm
content: Hello,What do you think about isolation the oscilloscope RIGOL DS1054Z from the mains with two 40VAC transformers: 230VAC->24VAC 40VA 24VAC->230VAC ?I can also try isolate the electronic system powered by 230VAC mains current, but it controls infrared bulbs with a maximum power of about 100W, so these transformers are probably too weak, but the power requirement of this RIGOL DS1054Z oscilloscope is probably much lower, but its datasheethttps://assets.testequity.com/te1/Documents/pdf/rigol/Rigol-DS1054Z-Specification.pdfsays: Maximum 50 WThis oscilloscope powered by these two transformers has a chance to work, or is it better not to risk it and isolate the electronic system powered by 230VAC with a lower power bulb for testing?UPDATE20231228: RIGOL DS1054Z input power supply specs: 100V-240V 45Hz-440Hz ~LINE 50W MAX ~Fuse 250V T2A

author: wasedadoc
author_rank: Super Contributor
timestamp: December 27, 2023, 08:00:57 pm
content: Suggest you read all of these topics:https://www.eevblog.com/forum/testgear/floating-scopes/https://www.eevblog.com/forum/beginners/is-it-safe-to-measure-mains-voltage-with-my-rigol-dho804

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 08:23:42 pm
content: Quote from: wasedadoc on December 27, 2023, 08:00:57 pmConnecting the outputs of the 230VAC->24VAC transformer to the 24VAC outputs of another identical 24VAC->230VAC transformer as inputs should provide ~230VAC output isolated from the mains power supply, this is not subject to discussion, but is there a chance that these 40VA transformers will be able to power the oscilloscope in this way, because unfortunately I do not have a transformer 230VAC -> 230VAC with a power of say 100WI used to watch it a long time ago

author: wasedadoc
author_rank: Super Contributor
timestamp: December 27, 2023, 08:33:50 pm
content: The main point of the discussions I pointed you to, is the potential danger to you.

author: BrokenYugo
author_rank: Super Contributor
timestamp: December 27, 2023, 08:43:59 pm
content: Never float/isolate the scope, always isolate the DUT.

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 08:46:37 pm
content: Quote from: wasedadoc on December 27, 2023, 08:33:50 pmNope, I'm doing well with mains voltage, that's why I galvanically isolate electronic systems during testing, but I'm just not sure what typical power consumption to expect with this oscilloscope RIGOL DS1054Z, because it would be better to have the oscilloscope isolated than the electronics, because in this case the system analyzes the mains voltage, so it is better to be powered directly from the mains rather than from a transformer, while the oscilloscope power supply should probably cope with slightly different power supply parameters after passing through these two transformers , the only question is whether they are not too weak even though they have 24VAC 40VA output

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 08:49:21 pm
content: Quote from: BrokenYugo on December 27, 2023, 08:43:59 pmWhy not? Battery-powered meters are, after all, isolated

author: wasedadoc
author_rank: Super Contributor
timestamp: December 27, 2023, 08:56:29 pm
content: Quote from: eneuro on December 27, 2023, 08:49:21 pmYou appear to be in the queue for the Darwin Award.

author: Psi
author_rank: Super Contributor
timestamp: December 27, 2023, 08:56:53 pm
content: It'sveryfrowned upon due to the risks of being shocked when you have the scope probe clip on something at HV and therefor your entire scope ground is now at HV including the metal case and all the unconnected BNC probe terminals, usb socket, all the rear trigger BNC, VGA port which you might touch when reaching around the back etc.. There are so many paths to get a shock or short out mains if you interface the scope in any way to some other device that is grounded to earth.Or worse, connecting it to something else that isn't grounded and now you two devices with exposed live parts. etc..Even if you are 100% confident working like this others may walk into the room when you are in the bathroom and touch something.The risks are very high and also very non-obvious.So EE's will correctly tell you to never do it.You might do it anyway but most people just don't want it on the conscience when you or someone else gets a shock.Buy/build some isolated active probes instead.Or maybe buy a portable battery powered scope, which you will notice are buildverydifferent with no exposed metal ground points.

author: coppercone2
author_rank: Super Contributor
timestamp: December 27, 2023, 09:26:56 pm
content: https://www.elektormagazine.com/magazine/elektor-201409/27026

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 09:42:03 pm
content: Quote from: Psi on December 27, 2023, 08:56:53 pmThese two transformers are intended to protect the oscilloscope by isolating it from the mains supply against damage in the event of connecting the GND of the oscilloscope to some part of the tested system with a mains voltage of 230VAC, or in a situation when, as a result of some error in the tested system, mains voltage appears on the GND of the oscilloscopeIt is obvious that isolating the oscilloscope from the 230VAC mains power supply to which the tested electronic system is connected does not protect the person who operates it if that person touches the non-insulated components of the oscilloscope that are connected to the measured system for measurement purposes using testers that do not ensure a safe level of insulation, but let's not exaggerate, because 230VAC is not a high voltage of the order of kilovolts, so if you have an oscilloscope isolated from the mains power supply, just disconnect the mains power supply of the tested element completely, remove the plug from the mains socket, and then you can easily connect the testers to the tested parts of the system but still be careful when the oscilloscope power is not completely disconnected , turn on the power supply to the system. , remembering not to touch anything uninsulated in the oscilloscope during the test unless you have specialized probes.

author: Psi
author_rank: Super Contributor
timestamp: December 27, 2023, 09:44:09 pm
content: Quote from: coppercone2 on December 27, 2023, 09:26:56 pmFound a PDF of that article here.https://ia800804.us.archive.org/20/items/ElektorMagazine/Elektornonlinear.ir2014-09.pdfHas anyone seen a more modern version of that, perhaps one you can just order already made up?

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 09:51:44 pm
content: Quote from: coppercone2 on December 27, 2023, 09:26:56 pmIsolated oscilloscope probes will not help in a situation when an inattentive person accidentally touches some non-insulated element in the tested system under mains voltage, even with one hand, while connecting such a tester with the other, and even in a situation when such a system is isolated from the mains voltage, because in a situation when he holds the tested device with one hand system and the second one with the tester accidentally touches something not insulated from mains with his second hand, he will still feel the power from the mains socket

author: Benta
author_rank: Super Contributor
timestamp: December 27, 2023, 10:36:19 pm
content: Darwin Awards, indeed...

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 10:48:48 pm
content: Quote from: Benta on December 27, 2023, 10:36:19 pmIf someone uses a earth grounded oscilloscope, they have a good chance of winning such a prize thanks to the black alligator from the regular probe

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 27, 2023, 11:02:04 pm
content: This is where a battery powered, Wifi or fiber connected scope would make a lot of sense.

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 11:21:07 pm
content: Quote from: NiHaoMike on December 27, 2023, 11:02:04 pmNope, I do not need it since for mains zero crossing I use optocoupler, so a certain part of the system is optically isolated from the mains power supply and besides, these are not high voltages of the order of kilovolts, but only electricity from the wall socket.

author: wasedadoc
author_rank: Super Contributor
timestamp: December 27, 2023, 11:32:10 pm
content: Quote from: eneuro on December 27, 2023, 11:21:07 pmSo, no-one living in a place where the only electricity is from wall sockets never died by electrocution there?

author: robert.rozee
author_rank: Frequent Contributor
timestamp: December 27, 2023, 11:38:51 pm
content: Quote from: NiHaoMike on December 27, 2023, 11:02:04 pmnot quite...bear in mind that your DMM (for example) has a fully insulated containment case that is good for 600v or so, insulated leads that are good for 600v andcarryonlyoneconductoreach, said leads have probes at the ends that are equally well insulated and expose just asingleconnection each.compare this to a floating or battery-powered regular oscilloscope:1. the oscilloscope case is NOT fully insulated to 600v or so, with exposed metal parts in multiple places,2. the oscilloscope probes are connected by a light-grade coax cable that is NOT insulated to any significant degree. ie, any small nick in the outer sheathing of the coax cable exposes the same voltages that the scope is probing,3. said coax cable also carries BOTH measurement conductors with just a thin inner sheathing separating the two. ie, if a high voltage happens between probe tip and (albeit floating) ground then there is negligible insulation present between the two,4. probes themselves have negligible insulation, including the x1/x10 switch, and exposes both measurement points (signal and 'ground') in close proximity,5. a regular oscilloscope lacks any of the input protection or explosion containment of a DMM.in summary: instruments like a Fluke Scopemeter areverydifferent to a regular oscilloscope that is floating. the case of a Fluke Scopemeter (or similar) has to insulate against 600vandbe able to contain explosion upon fault; the leads need to have 600v outer insulation through their entire length, as well as 600v insulation internally between signal and ground; the power supply (if not battery powered) needs to be similarly insulated and maintain that insulation upon explosion due to fault.cheers,rob :-)

author: eneuro
author_rank: Super Contributor
timestamp: December 27, 2023, 11:49:11 pm
content: Quote from: wasedadoc on December 27, 2023, 11:32:10 pm

author: Benta
author_rank: Super Contributor
timestamp: December 28, 2023, 12:12:34 am
content: "Imagination is more important than knowledge..."Well, if you add in health insurance and emergency services, you have a home run. Enjoy the experience.

author: robert.rozee
author_rank: Frequent Contributor
timestamp: December 28, 2023, 01:55:32 am
content: Quote from: eneuro on December 27, 2023, 11:49:11 pmtrue... if it happens, you may even be lucky enough to join a most illustrious club:https://en.wikipedia.org/wiki/List_of_inventors_killed_by_their_own_inventionmost notable, "Marie Curie (1867–1934), was a Polish-French physicist and chemist who conducted pioneering research on radioactivity and credited for discovering radioactive Polonium. On 4 July 1934, she died at the Sancellemoz sanatorium in Passy, Haute-Savoie, from aplastic anaemia believed to have been contracted from her long-term exposure to radiation, some of which was from the devices she created".cheers,rob :-)

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 02:11:47 am
content: Quote from: eneuro on December 27, 2023, 11:21:07 pmAre there exposed metal parts on your oscilloscope? Touching these metal parts will remain a mains shock hazard, the isolation transformers do not help here.

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 02:18:49 am
content: Quote from: robert.rozee on December 28, 2023, 01:55:32 amAI do not intend to use this oscilloscope in combat conditions on Mount Everest, only for peaceful purposes at home

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 02:40:34 am
content: What country are you in and what is your mains system?For example, Japan has no mains earth, so isolating the oscilloscope is less of a problem. If you are in Australia which has mains neutral connected to earth, then electric shock is a real hazard.I see that you're 240V, so in Europe?

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 04:27:54 am
content: Quote from: Andy Chee on December 28, 2023, 02:40:34 amIt is 230VAC 50Hz as in many European countries, but the difference between 220VAC and 240VAC is less than 5% compared to 230VAC

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 04:34:52 am
content: Quote from: eneuro on December 28, 2023, 04:27:54 amThe key issue is earthing. I will assume that neutral and earth are connected in your country.If the above is true, there will be an electric shock hazard when touching any metal part of the oscilloscope (or any part of the oscilloscope with weak insulation). Your isolation transformer will not protect you.If you understand this and are willing to proceed, then good luck to you.

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 05:21:39 am
content: Quote from: Andy Chee on December 28, 2023, 04:34:52 amI don't worry about myself because I know physics very well, I only worry about the RIGOL DS1054Z oscilloscope and these two 230VAC 50Hz 40VA 24VAC transformers in such a cascade connection to obtain an isolated ~230VAC power supply from the mains socket.I will need to test the typical power consumption of the oscilloscope's from mains power socket to know what loads to expect during typical work with RIGOL DS1054Z because in its datasheet I saw the max power consumption of 50W, which seems quite a lot

author: Someone
author_rank: Super Contributor
timestamp: December 28, 2023, 06:35:50 am
content: Quote from: Andy Chee on December 28, 2023, 04:34:52 amIn general this takes a product which is safe in a single fault condition (many additional possible pathways/faults beyond what has been enumerated in the thread so far) and eliminates that protection, resulting in a safe only under ideal circumstances product, hello appliance Class 0:https://en.wikipedia.org/wiki/Appliance_classes#Class_0. Too many (and further unknown) threats to be worth the tradeoff of using a differential probe.

author: coppercone2
author_rank: Super Contributor
timestamp: December 28, 2023, 07:03:12 am
content: Quote from: eneuro on December 27, 2023, 09:51:44 pmwhat the hell are you talking about. You use a insulated probe with it, like from a scope meter. a BNC connector has fingers that make the outer connection, you would obviously use a plastic body. The only exposed thing is the tip of the probe.Not sure if you are familiar with insulated alligator clips either. Its pretty hard to shock yourself with one.Even a regular tektronix oscillscope probe literary has no places to shock yourself with it. The ground lead is clipped onto a recessed notch. You would need to grab the very tip of the probe, with the hook removed and if you get a real insulated probe (fluke), you would need to pull back a sheath to touch the ground at the tip if no hook is installed, they have spring loaded sheath that covers literary any exposed metal.And if you are getting that near a probe tip, then you are just failing, because it means your fingers are like right on top of a live conductor that you can probe.and the ADUM chip on that isolation amplifier is good for... 4000VAC.

author: robert.rozee
author_rank: Frequent Contributor
timestamp: December 28, 2023, 07:24:35 am
content: sighs... it truly is so - common sense is theleastcommon thing in the universe

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 07:49:26 am
content: Quote from: robert.rozee on December 27, 2023, 11:38:51 pmAs you can see in the attached photo of the RIGOL DS1054Z oscilloscope in the first post in this thread, its housing is not metal but plastic, there is nothing metal sticking out of the USB connector, and the USB cable has a plug that is not metal but insulated.The only metal elements that can be touched in this oscilloscope are the four BNC connectors, but I have not checked whether the metal parts you can see are GND or signal ones, I only suspect that GND is hidden inside the BNC, anyway I see no reason to touch it with bare hands. these metal elements in an oscilloscope connected to the power supply or when testing some electronic system

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 07:57:37 am
content: Quote from: eneuro on December 28, 2023, 07:49:26 amIf you isolate the oscilloscope with the transformers as you are proposing, and a mains fault occurs (or improper probe connection), ALL metal parts will become live with 240V. It doesn't matter if it's GND or signal, both will become live. The USB ports will also become live with 240V, including any laptop connected.

author: 2N3055
author_rank: Super Contributor
timestamp: December 28, 2023, 08:00:53 am
content: Quote from: eneuro on December 28, 2023, 07:49:26 amAll BNC including ones in the back are direct GND. Metal posts on the right for probe compensation are GND and low impedance signal referenced to ground.You are missing the point here.While scope can be floated and some people survive it, it is dangerous practice, that can be used only in very controlled manner.By virtue of what can be read from your posts, many members concluded you should not be doing this, because you obviously don't have enough knowledge about it to do it in a way not to hurt yourself..That is the jist of it, without false political correctness..You are welcome.

author: Swainster
author_rank: Frequent Contributor
timestamp: December 28, 2023, 09:06:19 am
content: This has been discussed here:https://www.eevblog.com/forum/testgear/ground-of-oscilloscope-always-connected-to-earth/, and from that thread is this nice pic of a safely isolated scope:That said, identical back to back transformers will not get you back to your original mains voltage. I'd guess that you would maybe get around 200VAC after the second transformer, though it depends on the particular transformers that you are using - small ones tend to be worse for this kind of behaviour.Edit: well, I screwed up the image linking, but hopefully you can at least see a clickable thumbnail at the bottom of the post

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 02:06:45 pm
content: Quote from: Swainster on December 28, 2023, 09:06:19 amIt is obvious and this is the subject of this thread, whether this oscilloscope has a chance to work properly when powered from the outputs of the second transformer, and not safety issues, because I have ordered three such transformers 230VAC 50Hz 40VA 24VAC and the tested electronic system can also be powered by isolated ~230VAC, and what the galvanically isolated Vmax will be is not so critical in the case of the tested electronic system, but it would be better to have the tested system powered directly from a 230VAC mains socket during these tests, but there is no need to connect the oscilloscope via USB to a computer or laptop.

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 02:13:55 pm
content: Quote from: 2N3055 on December 28, 2023, 08:00:53 amThe topic of this thread is not about safety issues, but the possibility of using these two 230VAC 50Hz 40VA 24VAC transformers connected in a cascade to power the RIGOL DS1054Z oscilloscope not from the mains socket, but isolated from the mainsMost of the posts are off-topic in this thread

author: RoGeorge
author_rank: Super Contributor
timestamp: December 28, 2023, 02:51:44 pm
content: Quote from: Andy Chee on December 28, 2023, 02:40:34 amFromhttps://plugtravelguide.com/japan/

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 03:08:09 pm
content: Quote from: RoGeorge on December 28, 2023, 02:51:44 pmHa! I can tell you've obviously never used a power point in Japan!https://questionjapan.com/blog/electrical-outlets-in-japan/Quote

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 03:51:51 pm
content: Quote from: Andy Chee on December 28, 2023, 03:08:09 pmIt does not matter because the range of mains voltage and frequency is large for this oscilloscope:RIGOL DS1054Z input power supply specs:100V-240V45Hz-440Hz~LINE 50W MAX ~Fuse250V T2A

author: RoGeorge
author_rank: Super Contributor
timestamp: December 28, 2023, 03:59:40 pm
content: Never been to Japan, but I highly doubt there could be a system where current leaks from the power wires to Earth can be neglected. Parasitic capacitances from a power wire to Earth are big enough to electrocute, so you have to have an unballanced power line, where one wire is guaranteed to be connected to Earth (the neutral).I think in Japan, too, one of the 2 wires is always earth (or neutral), and that's the reason they made the width of the pins different, to ensure earth (neutral) wire always goes to the exposed metallic part of an appliance, and not the phase (hot). Any Japanese electrician to confirm or dismiss this, please?If the power mains were to be a truly ballanced transmission line, then either of the 2 wires will be an electrocution hazard.

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 04:40:38 pm
content: Quote from: RoGeorge on December 28, 2023, 03:59:40 pmBe careful because the Earth can also electrocute you with atmospheric electricity ~200V/2m

author: bdunham7
author_rank: Super Contributor
timestamp: December 28, 2023, 04:56:02 pm
content: Quote from: eneuro on December 27, 2023, 08:49:21 pmBecause, assuming the battery-powered scope or meter is properly designed to be used as an isolated instrument, it doesn't expose the user to the live voltages that it is reading. If you float your Rigol as you propose, then there is thepotentialfor every exposed metal part of the scope--each BNC connector shell, the USB jack, whatever other connections are on the back, as well as every device that might be connected to those things--to be at mains voltage relative to actual ground, also known as your body parts. And if you aren't worried about the shock hazard, good luck with the common mode noise issues.But yes, to answer your question, two such transformers in the configuration you mention should power up your scope.

author: RoGeorge
author_rank: Super Contributor
timestamp: December 28, 2023, 05:03:17 pm
content: Quote from: eneuro on December 28, 2023, 04:40:38 pmI don't know what that picture is suppose to be, and how it is related to a quote without any text in it. V/m is the unit to measure the intensity of the electric field, that's very different from mains power.My post was about why I guess there is a dedicated neutral wire in Japan, as a followup to what Andy Chee wrote, and from which one like me might take it as "in Japan there is no neutral wire, both mains wires are hot".

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 05:32:52 pm
content: Quote from: RoGeorge on December 28, 2023, 05:03:17 pmIt's a shame electroBOOM didn't test out the Japan power points while he was there. After all he tested the power points in England, Italy, Hawaii, and Cuba.And keeping with the thread topic, electroBOOM also attempts mains measurements with his oscilloscope

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 05:44:11 pm
content: Quote from: Andy Chee on December 28, 2023, 05:32:52 pmThere is no point in watching idiots inserting shorted power lines without fuses into mains power sockets

author: Andy Chee
author_rank: Super Contributor
timestamp: December 28, 2023, 06:50:41 pm
content: Quote from: eneuro on December 28, 2023, 05:44:11 pmActually there is a point..... you immediately learn what NOT to do.So I recommend you watch his oscilloscope video to learn what NOT to do.

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 08:33:34 pm
content: Quote from: Andy Chee on December 28, 2023, 06:50:41 pmTransformers and fuses ordered to isolate the oscilloscope from the power socketKnowledge of physics at university level is sufficient to avoid making such stupid mistakes.I don't have time to watch such stupid videos, made by donkeys who want to become famous on the Internet by posting such bullshit.

author: coppercone2
author_rank: Super Contributor
timestamp: December 28, 2023, 08:36:21 pm
content: those symbols you saw in university actually exist off the chalk board and people put them in metal boxeshttps://apkpure.com/mighty-troll-simulator/com.yamtar.mightytroll

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 08:44:20 pm
content: Quote from: coppercone2 on December 28, 2023, 08:36:21 pmIn the garbage of videos positioned by Google, it is sometimes difficult to find valuable lectures by professors from MIT or such as this one which shows that physics works not only on the blackboardQuote

author: bdunham7
author_rank: Super Contributor
timestamp: December 28, 2023, 09:04:04 pm
content: Quote from: eneuro on December 28, 2023, 08:33:34 pmHaving completed a university degree in that very subject years ago, I'd say that if you paid attention (and did the math) you would acquire sufficient knowlege and ability tobe able to learnthe details of many fields such as electronics, mechanical engineering and so forth. However if you imagine that with that level of education thatyou already knowall those things, then you're a flaming idiot. And if you screw up what you're attempting, the 'flaming' might be literal, as suggested by your comment:QuoteSo what specific hazard are you intending the fuses to guard against? Where will you place them? And how did you size them?

author: eneuro
author_rank: Super Contributor
timestamp: December 28, 2023, 09:18:03 pm
content: Quote from: bdunham7 on December 28, 2023, 09:04:04 pm

author: coppercone2
author_rank: Super Contributor
timestamp: December 28, 2023, 09:24:21 pm
content: you know that picture is at a source impedance in the god knows how many ohms and mains impedance is in the miliohms.

author: bdunham7
author_rank: Super Contributor
timestamp: December 28, 2023, 09:39:26 pm
content: Quote from: eneuro on December 28, 2023, 09:18:03 pmSomeone--who I loathed at the time and probably still do--once told me that if you can't clearly express something that you think you know, then you clearly don't actually know it. Or something like that. That's not always completely true, but I've found it to be so more often than I would have originally expected.

author: IanJ
author_rank: Unknown
timestamp: December 28, 2023, 10:48:26 pm
content: Quote from: eneuro on December 28, 2023, 08:33:34 pmSo you’ll build it, it’ll work and you’ll have a smile on your face……..till one day you make a mistake (as we all do no matter what experience) and you’ll blow the back side off your test gear…….or worse.I don’t need to tell you what mistakes you could make, it’s obvious.Ian.

author: wasedadoc
author_rank: Super Contributor
timestamp: December 28, 2023, 11:01:51 pm
content: Rarely has the expression "It's your funeral" been so apposite and literal.

author: eneuro
author_rank: Super Contributor
timestamp: December 29, 2023, 01:28:52 am
content: Quote from: IanJ on December 28, 2023, 10:48:26 pmNobody is perfect. I'm nobody.Don't disturb a genius at work

author: Andy Chee
author_rank: Super Contributor
timestamp: December 29, 2023, 02:11:50 am
content: Quote from: eneuro on December 29, 2023, 01:28:52 amNot sure what your schematic is supposed to show. Mains powered microcontroller?I posted a document along those lines in another thread, which you may be interested in:https://ww1.microchip.com/downloads/en/appnotes/00954a.pdf

author: eneuro
author_rank: Super Contributor
timestamp: December 29, 2023, 02:50:10 am
content: Quote from: Andy Chee on December 29, 2023, 02:11:50 amNope, It is not the control system that is supposed to generate infrared light, but a 100W IR bulb, but In this document they propose the use in sectionQuote10W2k resistor at 110VAC mains voltage and in addition I have not 110VAC but 230VAC from the socket

author: Andy Chee
author_rank: Super Contributor
timestamp: December 29, 2023, 03:21:44 am
content: Quote from: eneuro on December 29, 2023, 02:50:10 amIf needed, use the math formulas to recalculate using 230VAC 50Hz.I agree, the resistive power supply is a waste of energy. But the capacitive power supply is the more practical one.

author: eneuro
author_rank: Super Contributor
timestamp: December 29, 2023, 04:04:28 am
content: Quote from: Andy Chee on December 29, 2023, 03:21:44 amNot true, because it depends on the environment in which the system powered in this way is to operate, because when I control a 100W IR lamp to heat a room, there is no loss of energy because the <1W used to power the control system does not matter, especially since the whole thing is turned on by a switch, so there is no power consumption when there is no need to use the lamp.

author: Andy Chee
author_rank: Super Contributor
timestamp: December 29, 2023, 04:29:28 am
content: Quote from: eneuro on December 29, 2023, 04:04:28 amHere's another lamp dimmer, using capacitive drop power supply, and using a triac (instead of MOSFET). It can be recalculated for 230VAC 50Hz.https://ww1.microchip.com/downloads/en/AppNotes/40171a.pdfThe 12C508 is old, and could be upgraded to a 12F675 or ATtiny, if required.

author: eneuro
author_rank: Super Contributor
timestamp: December 29, 2023, 06:32:36 am
content: Quote from: Andy Chee on December 29, 2023, 04:29:28 amI am not looking for any circuit schematics of the system to control my IR lamp because I have already tested it in the simulator, I am just preparing a PCB in KiCad and software for AVR, as well as an isolated oscilloscope and a logic analyzer to check whether everything works as predicted by the computer simulation.Transformers are already nearby

author: Andy Chee
author_rank: Super Contributor
timestamp: December 29, 2023, 07:28:18 am
content: Quote from: eneuro on December 29, 2023, 06:32:36 amAt the beginning of this thread, you asked questions about two transformers for isolating your oscilloscope, because you were not sure.How can you be sure about your circuit simulation?