EEVblog

A look inside a Swiss made Schaffner NSG200E Mains Interference Simulator after it released the magic smoke.
A very unusual bit of kit that tests products for mains line interference like lightning strikes, transients, and dropouts.
May involve alien crop circles.
The Dumpster Diving video: • EEVblog #1134 - Dumpst...
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[@Seegalgalguntijak]

LOL @ "you don't see many Elkos" - after all, Elko is just an abbreviation of "Elektrolytkondensator", which means electrolytic capacitor. And those are basically everywhere ;)

[@jamisusijarvi646]

I was thinking exactly same. In Finland we shorten elektrolyyttikondensaattori (electrolytic capacitor) to elko.

[@juweinert]

Check out my comment. We discussed a bit over there and we found out that there is a brand named "Elko", which Dave probably was referring to, and then also some German caps with the designation of "ElKo" 😂

[@juweinert]

And ​@@jamisusijarvi646​ thats an extremely nice word!

[@Audio_Simon]

Suffering from audio ELKOholic syndrome.

[@denisohbrien]

when I hear elco I think ElCamino. and im in the uk. we never got el caminos. :/ i blame the internet

[@gregadams558]

Calibration Not Required. That needs to be a t-shirt.

[@LittleRainGames]

That dumpster is a gift that just keeps on giving

[@douro20]

I didn't know Schaffner made these. They are certainly one of the leading manufacturers of noise filtering equipment, and the ubiquitous integrated noise filter we're all familiar with was an original invention of this company.

[@__qqq__]

It let the smoke out because you turned it on before taking it apart :)

[@MaxKoschuh]

8:24 it is very unlikely that there's only one tiny hot spot on a large coil like that 10:12 one of the RIFA caps might have a hidden vent hole for magic smoke

[@uiopuiop3472]

hidden vent hole? how it is hidden gentlesir bytheway (b tw)

[@maxtorque2277]

The large input filter and Common mode choke make sense when you realise that this device must keep the DUT nicely isolated, both in terms of receiving any perturbations from local noise on the mains used to drive the test, and to prevent the noise and surges it actually injects into the DUT from coupling back up the supply and into the mains powering the unit!

[@EEVblog]

Indeed.

[@garbleduser]

A bad device under test could have had a ground loop to the chassis through a shorted "safety cap." This happens when people used this on metal tables and tested MUCH older equipment. Someone tests their old heathkit transmitter on it and BOOM...

[@mrnmrn1]

​@@garbleduser I think you misunderstood the type of isolation Max Torque mentioned. This unit doesn't have an isolation transformer, the DUT is not galvanically isolated from the mains. Max talked about the extreme filtering between the mains and the output, which is intended to isolate (filter out) the surge pulses (generated by the instrument), from the mains supply, otherwise you could inject the pulses into the electric network of the whole building.

[@AliOpridai]

Hi! I need help with a project. I am trying to turn Dell AC511 sound bar (Monitor speakers) into portable speakers. Their "aux in port" dont work when turn on using a powerbank or a wall charger. Aux in only work if connected to a PC USB port, Probably some communication in the D+ D- ports. So is there a way that we can use a power bank and send some sort of a signal to D+ or D- as well to make the "Aux in" work ? It works with a router USB port because router also communicates through D+ D- pins of the USB.

[@AZREDFERN]

My guess is it let the smoke out before they threw it away. Then the contact between the exposed coils oxidized, pushed apart, and created an air gap. Then it worked fine for you until you put any kind of load on it.

[@mrnmrn1]

Nope, I'm 99.9% sure the choke is fine. The black mark is some paint from the core, dissolved in the potting laquer during dipping. The smoke came from one of the RIFA paper capacitors, or the ITT cap might be a PIO which vented. The EMC filter inside the mains input IEC connector might also be the culprit, since it's also a Schaffner made one, there might be RIFA MP caps inside.

[@DasMrOSi]

Elko is short for Elektrolyt-Kondensator (Electrolytic Capacitor)

[@DVSProductions]

Exactly XD Elko isn't a brand

[@tweakpc]

Das kann ich bestätigen / I can confirm that

[@polam12]

Frako is the brand ;)

[@tweakpc]

@@polam12 Yes, an old German brand

[@alexreeve]

yes its from "Frankfurter Kondensatoren Fabrik" :)

[@cambridgemart2075]

Perhaps it was tossed after failing an insulation test due to a breakdown in the CM choke.

[@EEVblog]

Certainly possible!

[@robozstarrr8930]

@@EEVblog anytime ya see transformers w/sq Cu wire it's to obtain better magnetic coupling than round wire, & ( Sq wire ) is used in combo with Bifilar winding method on the Xformers core. The disadvantage is poorer HF isolation & dialectic isolation between Pr & Sec windings. I tested equipment like that w/ storage scope & 250 watt heat sunk 1.0 ohm 1% precision resistor ( we calibrated the resistor as well ). Key testing was confirming waveform/timing & energy dumped under the curve b4 use in transient protection designs & components. Lov what ya do...Cheers

[@EEVblog]

roboZ starrr Thanks for the detail

[@Audio_Simon]

@@robozstarrr8930 You sound knowledgeable regarding transformer design. Can you recommend some reading to get me started on the subject? Specifically audio signal transformers.

[@robozstarrr8930]

​@@Audio_Simon best i found was "practical transformer design handbook by eric lowdon - 1980. not much has chged w/magnetics since then. ( get the hardcover version ). another book "AC Power Systems Handbook", has alot more than xformers ( diodes, xistors, etc. )(by Howard W Sams) but ya can google the xformer chapter online ( gee, i wunder why! ) .. good reads...

[@brucepickess8097]

Hi, I have used this equipment for post office pre submission testing to meet post office security approval. The testing was on mains powered electronic postal franking machines. These machines effectively hold post office revenue . And very stringent testing was required to ensure that there could be no corruption or possible fraudulent attempts to defraud the postal authorities. Testing was to UK, US, and European postal authoritie standards. I also did ESD testing using Schaffner equipment. I worked for a company called Neopost which at one time came under Alcatel.

[@Glimmrelais]

KACO is an old german company - Kupfer Asbest & Co. They made vibrators for vibrator power supplys and relays in the past, nowadays they only make sealing elements. I have a really old 12V DC to 220V AC inverter with a massive vibrator cartridge made by KACO, a wonderful thing that wheighs a ton and produces a nice humming sound when energized :)

[@geronimostade8279]

The 400 Hz tab is most likely for aviation based testing. They usually will have 115 Volts by 400 HZ driven by the engines.

[@Basement-Science]

Ah, I suppose you would want a lower inductance on a 400Hz system, right?

[@brainndamage]

@@Basement-Science yup, the inductance at 400Hz might be too high and cause saturation

[@kilrahvp]

IMO the 400Hz thing is irrelevant in this device, they likely just reused an existing transformer frame and PCB from another product to make the common mode choke for this one.

[@kilrahvp]

@@michaelblaser6088 Yes I know but the common mode choke visibly doesn't have multiple taps in the first place.

[@Audio_Simon]

Brilliant supposition thanks!

[@richfiles]

At my old job, we had a massive California Instruments rack mount 90° 2phase inverter that could generate 400 Hz outputs anywhere from a few volts to a few hundred volts. We used it for testing motors and synchros intended for Defense and aerospace applications. The inverter was far too large for me to salvage intact, but I did salvage the old waveform generator from it when we scrapped it. The chokes and transformers in it put this to shame... Though at least it's wires were standard round solid copper wire, and not freakin' bus bars! WOW! Your bit of kit wins in that department!

[@gautamdamodaran]

I think 115V/400Hz is a standard power supply for aircraft equipments.

[@richfiles]

@@gautamdamodaran That's exactly what it's used for. Generally, transformers and other electromagnetic components can be physically smaller for a similar power rating at higher frequencies, so there is a mass savings benefit to making 400Hz the standard for aerospace electronics. United States military standard MIL-STD-704 is responsible for more or less making the use of 400 Hz a standard for aircraft. The reason we don't use 400 Hz in power line distribution, is that it's not economical to transmit over distances, due to increased series impedance.

[@mrnmrn1]

Dave! Please check those RIFA paper EMC caps at 10:21, I'm pretty sure they are the culprit, the choke should be fine. The black spot is probably some paint, dissolved from the core into the potting laquer. Also the ITT cap might be a PIO, and if so, it should be replaced. There's an other RIFA paper cap in the injection module at 17:08 on the back of a switch.

[@CraftAero]

... and here's me testing my audio power supplies by plugging in circuit and cycling incandescent/flourescent lights, vacuum cleaners, blenders, microwave ovens, etc.

[@Kalvinjj]

Simple and realistic. I'll give you a thumbs up for the method, the so called "Elegant solution", or also the KISS if you know the acronym!

[@tablatronix]

I was wondering how someone would simulate inject noise like that, I am testing some instrumentation amps and was having different issues (with ground noise, when mc serial was connected to computer ) when a space heater was running and with led lights running, so I was turning stuff on and off and comparing tests, lol ugh

[@Y0urpants]

You can also wire up relays to the mains in such a way that they chatter at line frequency. It produces relatively broadband noise in both conducted and radiated emissions.

[@CraftAero]

@@Y0urpants Good idea. Hmmm... drive it with a MOSFET & frequency generator, and I could do some sweeps (limited by the relay's response time).

[@CraftAero]

@@Kalvinjj Thanks, as a Mech.Eng. I'm a big fan of Elegant Design. As a hobbyist, I looked for the most likely range of household devices to cause problems. My circular saw (@13.5A) wins, but... you wouldn't likely "hear" the line noise if you're using a saw, lol.

[@Sine1040]

It's a FRAKO, Elko stands for "ELektrolytKOndensator" in German a generic abbrevation used for electrolytics "Elco" in Dutch for example.

[@LordWaldema]

In German we don't say "The equipment must be grounded", we say "Fester Schutzleiteranschluss obligatorisch" and I think that's beautyful.

[@TheEPROM9]

I do love all this old retro stuff.

[@timmgiles]

Loving the R&S PSUs in the background :-) Another interesting teardown.

[@davidwilkie9551]

When talking about interference in QM, it's all about the significance of sync-integration and how it adds up, but the same principle in Electronic Devices is about how much (alien) bad news distorts the significant information...

[@l3p3]

Maybe the loose IC popped out when the unit was tossed. Could the meltdown been caused by that? Anyhow, we see an old rule again: When obtaining gear in an unknown state, always first open it and check for anything that could be wrong! That rule exists for that very reason!

[@EEVblog]

No chance that causing the smoke. But yeah, with checking inside visually first

[@achecase]

Well, you've got a few bobs copper there anywho.

[@andreamancausoft595]

7:24 RIFA condensator... they catch fire easily when old...

[@Zonkotron]

Oh yeah....all the time.....suckers.....and other similar looking units of the same age but from other companies too

[@tookitogo]

“Capacitor” is the word you’re looking for. “Condenser” is what they were called a very long time ago in English. “Condensator” is Germlish. ;)

[@andreamancausoft595]

@@tookitogo i know thanks, sometimes i do this mistake :'( it's because is similar to Italian (condensatore) :D So usually i write Condenser and after when i read i fix to Capacitor, this time i don't read the comment before send it :). But thanks for the correction :)

[@MrDominon]

That was also my tought. All of those resin potted, paper-foil capacitors tend to break & burn with big cloud of smoke smelling like amoniac or cat piss. So no nude virgins making them i guess...

[@gglovato]

yeah i noticed those small claymores too!, you can even see the case is already all cracked up

[@electronicsNmore]

That dumpster also have silver or gold bars inside? :-)

[@EEVblog]

People only dump gold bars for some reason

[@electronicsNmore]

@@EEVblog LOL

[@mickeythompson9537]

Love those old 'magic eye' buttons.

[@williamsquires3070]

Check the resistance between the windings of that common-mode choke - I can’t see it failing due to a short in one of the windings themselves; they’re not operating as a step-up/down transformer, so they’re not rated to have mains across them. It’s also possible that something else failed, not the choke; the crud might just be something that got spilled in there and dried up.

[@mfx1]

I used to work in a UK testlab back when EMC and CE marking was in it's early days, we used similar kit, some of it designed and built in house.

[@mfx1]

This is what the place looks like now. steve-morton.com/rtcg/rtcg-today/

[@_bodgie]

STC was a British company with an Australian arm that was acquired by Alcatel Australia in 1987, this explains the two asset tags. Alcatel did a "merger of equals" with Lucent Technologies to become Alcatel-Lucent, now it's all Nokia.

[@mattselectronics3425]

I don't understand how the common mode choke was failing. If the insulation breaks down and the adjacent wires touch, it is only less inductance. Not like line and neutral could touch. Or is the core grounded somehow and it shorted to this?

[@EEVblog]

I don't get it either

[@garbleduser]

I suspect the chip that popped out was a comparator, a regulating component, or a controller that was telling when mosfets to pull one side to ground.

[@garbleduser]

Being that the dangling chip is a DUAL BINARY UP COUNTER, could it have been not telling the board a number of pulses delivered, and causing the pulse generator to go into runaway? Datasheet: www.datasheets360.com/pdf/-7385397319899951011

[@robertw1871]

It depends on where it shorts, you could end up with a very low turns shorted transformer since it shares the same core, basically a center tapped autotransformer... would be interesting to see the coil teardown for root cause...

[@jaycee1980]

I dont think it's burned out at all. I reckon one of those RIFA caps let the smoke out

[@pa4tim]

those relais are also used in G&M Secutest PAT testers, pretty expensive things.

[@Sir_Uncle_Ned]

That is a bloody serious choke! They clearly don't want noise on the reference input!

[@sickparrot3]

Brings back memories, we used one of those bringing our range of PLCs up to EN specs in the late 80's

[@nrdesign1991]

Perhaps it wasnt a good idea to let it have firing away ungrounded and unloaded.

[@tlv1117]

I was wondering the same. Could it have not been designed to be run with no load?

[@user-xlario]

This kind of equipment could work without load.

[@markkennard861]

Thanks for your comprehensive vids.. So where to now for this.. The dumpster ??

[@Kvandy15]

Imagine Dave running down the hallway at the office building with a smoking box.

[@NickNorton]

07:17 Are you sure it wasn't that Rifa style X cap in front of the choke that released the smoke. It does look as if it has a crack in the top of it. They are notorious for failing.

[@dhpbear2]

9:00- I'm guessing some filter capacitors were frapped.

[@jorno1994]

"confidence is high" jinxed af

[@jockinafrock]

Standard Telephone & Cables (STC) I think we're bought by Plessey Telecom, merged with GEC Comms to become GPT. This then became Marconi Comms, which collapsed and was sold to Ericsson. So Ericsson probably are the current owners of any IP involved here

[@caseMasterxL]

Great vid

[@dickcheney6]

Maybe you should get a metal box to put things in if they start smoking. Just seems like a bad idea to put CARDBOARD over top of something that's smoking!

[@PlasmaHH]

On the schematic you can see the 50/60 and 400Hz thing too. my guess is that you are supposed to move one of the spade connectors to the other setting to get the right cap for the frequency in the filter.

[@jaycee1980]

RIFA film capacitors spotted. I can almost certainly bet one of those went short circuit, hence the magic smoke.

[@Audio_Simon]

EEVblog, any chance of a video about transformertransformer design parameters? From a spec your own point off view? Core copper percentage, winding style, geometry etc?

[@buckstarchaser2376]

Those transparent, linear, trim pots are very attractive. I'd like to get me some.

[@travis4798]

I think you should fix it. Might come in handy. Also looks vintage would probably fit right in with your collection of meters, etc.

[@cmscoby]

Very interesting teardown, Dave. Makes me want to move to Switzerland where they wind the bespoke inductors! ;-)

[@benbaselet2026]

Be sure to arrive in 1988 too

[@00Skyfox]

Are you going to replace that big inductor and get the unit working again?

[@ken2391]

I suspect the loose IC was the reason it was tossed out. Probably caused a lot of intermittent issues.

[@iamdarkyoshi]

Shame it let the magic smoke out, though it did make for an amusing segment in the video. Also its 3 in the morning here in the states, perfect time to watch youtube.

[@AliOpridai]

Hi! I need help with a project. I am trying to turn Dell AC511 sound bar (Monitor speakers) into portable speakers. Their "aux in port" dont work when turn on using a powerbank or a wall charger. Aux in only work if connected to a PC USB port, Probably some communication in the D+ D- ports. So is there a way that we can use a power bank and send some sort of a signal to D+ or D- as well to make the "Aux in" work ? It works with a router USB port because router also communicates through D+ D- pins of the USB.

[@willynebula6193]

I love me some socketed 74 series logic!

[@ebb2421]

Anyone have a diagram for VWR Accu Power model 4000 power supply. I found a substitute for the bad LCD display but there is an output failure going on....

[@seanet1310]

I would recognise that asset number anywhere (property tag) but not the vintage kit itself so obvious which office this came out of. Dave, if it hasn't hit the bin, the physical asset folder from the nameless company would likely have the schematic if you feel like contacting them and asking for Steve or Rob. The 400hz on the chock may indicate there is a module to generate old aircraft immunity pulses as an option and probably just showing the chock is speced for 50/60 Hz and 400hz. Something in the very early DO-160 or for-runner standards my guess. Maybe MIL-STD-461

[@juweinert]

15:15 Electrically isolated by a steel cable bridging the huge air gap? There must be a simple constructional reason for the distance when they use steel cable for the physical coupling, wouldn't you think?

[@ickipoo]

STC Australia was acquired by Alcatel in 1987. Alcatel was acquired by Nokia 2016.

[@mjouwbuis]

So now we know, the unnamed company is Nokia networks ;)

[@craign8ca]

Glad you didn't get a nasty shock from a charged cap.

[@dickcheney6]

My soldering gun fried itself, and I saw it smoke, it didn't scare me at first, it was just like "Darn, it broke" and just non-chalantly unplugged it: Then, I noticed that after about 30 seconds, it was still smoking. At that point I started to get scared it would actually ignite from still being hot. Thankfully it didn't. It seems that due to the thermal mass of coils in general, if they get hot enough to smoke, they're going to keep smoking for a minute or two.

[@urugulu1656]

why is this one resistor so much out of the board? does not look like a power resistor to me. so i dont think its to dissipate heat

[@ghlscitel6714]

These plugs are German Schuko outlets. Do you have them in Australia too?

[@Uko_]

As a fast simple fix, could you just short the choke? I would love to see the output on the scope!

[@sazman2000]

thanks dave, very intresting..........

[@electronash]

I may be tempting fate by posting before watching rest, but... 10:50 - It looks like the extra spade terminals allow it to take some filtering out of the circuit when a 400V supply is used? (I don't imagine 400Hz would normally be input via IEC socket on this type of product anyway, so maybe it was just an unused option on that specific choke?)

[@electronash]

btw, "Standard Telephone and Cables" was a company here in the Old Dart that was eventually bought by Nortel... en.wikipedia.org/wiki/Standard_Telephones_and_Cables I used to work for Nortel, and I believe their main R&D / fibre optics division in Harlow was on the old STC site. So yeah - that thing is pretty old. lol I spotted some 1986 / 1987 date codes in there. Amazing years for movies (Top Gun, Labyrinth, Robocop, Predator).

[@xtasy2k7]

No magic smoke footage ? That's a shame :(

[@gglovato]

with some "authentic aussie cussing" and panick involved, would've loed to see it, like electroboom hahaha

[@leocurious9919]

Indeed. I can see why the camera is not always rolling, its in the way, but this happens fairly often. So maybe always have a camera still running off to the side?

[@mxslick50]

Based on the panel marking on the 222A, lower left, I wonder if you're supposed to leave the NSG200 OFF when doing the test. Maybe the 222A was feeding those pulses back into the 222 and it caused the choke to flash over?

[@garbleduser]

Being that the dangling chip is a DUAL BINARY UP COUNTER, could it have been not telling the board a number of pulses delivered, and causing the pulse generator to go into runaway? Datasheet: www.datasheets360.com/pdf/-7385397319899951011

[@DjResR]

Live to earth fault in common mode choke perhaps? Maybe it is possible to rewind it with 2,5mm2 insulated wire or bypass the CM choke and resurrect that device for oscilloscope check?

[@gblargg]

5:41 So THIS is why you don't turn it on instead just take it apart.

[@dhpbear2]

11:40 - What's up with the 5cm-long leads on that 15-ohm resistor? (Answered later on) - inducing some inductance!

[@PointReflex]

redundance 101

[@Y0urpants]

Could also be thermal reasons to allow greater convection underneath the component. Didn't see a fan for airflow, so it may be for that reason.

[@chasmosaurus3]

@@Y0urpants Yeah seems like it would be thermal reasons. Traces on the PCB would give better results if you wanted inductance.

[@urugulu1656]

idea why the thing had a meltdown: you tried to generate the pulses but you did not have anything connected as a load (you can hardly call your multimeter a load). the thing could be that the load is supposed to deal with the pulses and their energy. with nothing connected to it at all the circuitry may have nothing where all this energy from the pulses can dissipate… the Designers may not have included a protection against use without load because it either may interfere with the test the equipement is supposed to do, or because they think that whoever uses this knows how to use it properly...

[@EEVblog]

I would be stunned if that was even possible. That's why they would have that filter inbetween, and the seriously over engineered choke

[@matthewmiller6068]

That may make sense... similar to how you can't key a radio transmitter without a test load (or antenna) without frying something

[@Traildust]

@@EEVblog Could it have been your unusually high supply voltage there in the lab? You had some crazy high voltage numbers on your multi, it was 247 something, that's way high!?

[@EEVblog]

Nope, still within spec

[@ethanpoole3443]

Matthew Miller Except in the case of radio transmitters it is the high voltage caused by the very high SWR (due to the impedance mismatch created by the missing antenna, with the SWR approaching infinity) that causes damage to the power amplifier transistor(s), though any decent transmitter will have Hi-SWR detection and automatically enters a reduced power state to protect the transistors. A well designed test device like this should be designed to survive the possibility that the device under test may shutdown or blow a fuse, etc., during the test without the test equipment going up in smoke as a result of the device disconnecting itself. Further, in a device like this they should know exactly what peak voltage to design to so as to ensure that the test equipment can safely survive its own high voltage pulses. I did not catch the schematic while it was briefly on screen, but if the choke that overheated was part of an LC filter then if the capacitor portion of that filter failed then you may end up with unusually high current flowing through the inductor that might lead to overheating.

[@ZomB1986]

That's odd. I saw nothing odd about this machine until I realized you're in a country with odd plugs and this one has normal plugs.

[@ethanpoole3443]

I disagree, clearly BOTH your countries MUST have odd plugs as neither look anything like our plugs! ;-)

[@CB0T]

I like these 'mechanical light' switch.

[@johnfrancisdoe1563]

So those windings are 6mm² copper plus insulation. That's a standard cable thickness for building feeds, obviously rated for much more than the 10A input connector and the 16A output connector should survive. So maybe it's used for low resistance rather than current capacity. Or maybe it's just the wire density in the coil causing severe derating of the copper.

[@markkrutzmann6862]

In continuous operation, around 2 - 2.5A per square millimeter is usual in iron transformers and inductors. So yes, it is a derating. Makes sense if you think about it as the generated heat has nowhere to go to.

[@rathorclemenger6125]

I'm curious, couldn't you just get a replacement unit for the 50/60 unit or do they not make them anymore? or something similar from a different company and just replace it with the new one?? As a side note: the Simulator as a whole could use a good cleaning.

[@station240]

You just give the big choke to a transformer rewinding service, and pay the resulting bill.

[@TheDefpom]

@10:55 c4, c5 or c6 x2 caps aren’t blown are they, have seen them fail several times.

[@EEVblog]

That's what I thought but they looked ok. And the smoke was coming more from the back where the choke burn is

[@TheDefpom]

EEVblog - the AC Input Filters fail too, I captured one blowing up on camera once, the smell was horrendous, it stank my lab out for 2 weeks ! #193 Who let the SMOKE out ! HP 8904A Multifunction Synthesizer Repair Part 1 kzbin.info/www/bejne/rqDHqHSbfKlsocU

[@mjouwbuis]

These types of caps come pre-blown from the factory, but sometimes it takes them a few years before it sinks in.

[@simontay4851]

2 weeks! Bloody hell. That must've really been smoking a lot for a long time.

[@ethanpoole3443]

Simon Tay Not necessarily, the electrolyte from some electrolytic capacitors can certainly stink things up for a remarkably long time before that smell finally wears off. Just *one* small electrolytic that failed my my oscilloscope power supply still reminds me of its death for a minute or two each time I power on the scope and that was several years ago despite having wiped down the chassis and scrubbed the power supply PCB clean with IPA to try and clean off the remnants of that electrolyte! For the first minute or two after I lower it on I’m faced with that awful smell and am left wondering “has another failed again?”.

[@punker4Real]

put the power supply in your weller soldering iron looks like the fuse did not fail

[@gotj]

That's a mercury wetted relay I think... (the orange one)

[@redoverdrivetheunstoppable4637]

yyyeeeeaaaahhhh... it sounds likely!! they say that they have a very fast rise edge for narrow switching

[@lucasimark7992]

Hello from Switzerland!!!

[@allthegearnoidea6752]

I would have bet you a whole british pound on it being a x capacitor failure. Shame you are so far away would have loved to had a go at winding a new choke or repairing it. I’m really interested in EMC test gear.

[@TheEPROM9]

You need to fix this, would be quite a useful to the lab addition.

[@yassm]

This is beatiful

[@twoody2148]

should try and power it directly :) cause it just seams the primary section is just a large switch/filter any way :)

[@TheEPROM9]

You might be able to rewire/delete the choke that burned out.

[@gblargg]

If I had a front-end like that with mega filtering, I'd slap that on the mains entry for all my electronics. That would filter almost any garbage coming in on the mains.

[@drjmansplace5174]

Magic smoke, once released, may clear you nose. Thumbs up.

[@PanoWorks]

"Confidence is high. I repeat, confidence *is* high." - I'd piss on a spark plug if I thought it'd do any good!

[@EEVblog]

Let the boy in there Major

[@PointReflex]

@@EEVblog Hmm, "War Games", "The Day After" or "First Strike" quote?, I ask because "First Strike" was made by the SAC/US Neocons, Inc. and when shit went real they used 'that' phrase... a scene directly copy/pasted on The Day After (since the US Army didn't want to cooperate with a director that didn't made clear that "Kruschev shot first") then I think it was later used as a reference in War Games.

[@markcummings150]

At 7:20 I see some possible suspects. The x2 RIFA mkt caps is my first guess at the source of the smoke.

[@jorget8740]

Hi. IEC have the 61000 family of standards for EMC, EFT Burst tests are IEC61000-4-4. @EEVblog let me know if you want to see what the pulse should look like. I have the newer version (Teseq branded) at work

[@stevenbiars6212]

Those beautiful old PCBs......

[@ChaZcaTriX]

This button design! :3

[@555circuitslab5]

Hello from Switzerland :-)

[@mikesradiorepair]

Here is the manual for the non "A" version. It's for the earlier NSG222. archive.org/stream/SchaffnerNsg222InterferenceSimulatorManual#mode/2up

[@Damien.D]

Looks like it worked perfectly, and self-test abused itself. Patented auto cal routine.

[@davidgustafik7968]

Pretty sure that the orange relay is a mercury relay - you can get very high speed pulses out of them.

[@WacKEDmaN]

im just guessing but, the labels on the choke would be what its actually filtering...50/60hz for mains...and 400hz for transients...just to smooth and isolate the mains input noise from the test...

[@benbaselet2026]

I bet it's there for the aerospace version where they just stick a 400Hz label on and triple the already horrendous price tag.

[@Sigmatechnica]

oooh look at those lemo connectors

[@randycarter2001]

Considering what you paid for it. Who really wants to fix it? You got a super tear down from it at the very least.

[@HazeAnderson]

7:30 pretty sure those copper bars were hammered by a real blacksmith! 😂

[@TheChipmunk2008]

Dave are you 100% sure it's the choke that's gone..... I'd be more suspicious of those capacitors on the other side of that board

[@EEVblog]

That's we the smoke mostly came from, rear part of the case. Caps looked ok on first glance

[@zaprodk]

@@EEVblog That choke looks absolutely fine. The brown stuff is the PU-laquer from dipping. I worked at a transformer manufacturing company and i'd say nothing is bad with that one. A failed Schaffner net filter or RIFA capacitor is your problem here. I binned a whole box of old Schaffner net filters since they all go thermo nuclear when powered after 20 years being unused where their integral RIFA caps have sucked up moisture. A classic!

[@EEVblog]

Yep, could be right, I spotted something upon closer inspection, will have to do a follow up video.

[@VK3NFI]

@@EEVblog @7:21 those Rectangle yellow MKP caps are absolute garbage the are in kenwood mixers I repair and they fail with age like clockwork, and the smell is like the wrong side of the garbage tip fire ..... I wold be going strait to them and it looks like one is cracked on the side in the footage but its a bit hard to tell.. edit. I'm betting they are on the input mains side and if that is the case you can almost be guaranteed that they will cause a TAG TEST fail . bad for the previous owner good for Dave....

[@ethanpoole3443]

That was my suspected cause of failure as well. Hopefully we’ll get a good follow up video out of the failure.

[@dandrehn]

"elko" haha. you don't see many electrolytic capacitors? Don't inhale that magic smoke, Dave :P