Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Hager,  sweet and easy.

That's essentially the same. Hager has bought Tehalit in 1996. 

https://www.rheinpfalz.de/wirtschaft_artikel,-tehalit-strebt-wieder-aufw%C3%A4rts-_arid,95221.html

Yep, what is more it is pretty good gear as well, I have been to their factory in Heltersburg a few times while I was working at Hagar UK, I used to get more Tehalit gear specified for projects and thus sold more than anyone else in the UK, BBC ratio and TV used it in their buildings. The BBC got through huge amount of it during their many rip outs and fit outs as well. They used to complain to me about the poor availability of certain items holding up their projects for a couple of small bits. I had regular meetings with top management in the UK and Heltersburg on their behalf, and won the argument. Urgent bits they would fly into Heathrow for them.

[AVGresponding]

Any device tying neutral and ground together within the device is verboten here and as you stated would have to be checked.

Not quite what I was thinking. A lot of people make the assumption that one of the two mains wires coming into a piece of equipment is at or near ground potential, more so if you have a clearly defined neutral like the UK does. It's an assumption that does not get tested when you plug something into a supply where the assumption is true (outside of fault conditions). That assumption is obviously not true if you connect to a US style 240V supply where the centre tap is at ground and both 'hot' and 'return' have significant AC potentials with respect to ground.

The danger here, as I see it, is not conscious design per se but casual assumptions like "Oh, that component is OK, as it can only see neutral and ground it'll only see more than a couple of volts" or "Yes, the clearance and creepage are tight there, but it's only a neutral." that tend to get ingrained because that's all you ever see domestically. It's probably only going to be corner cases and unusual use cases at that, but I'm only too aware of the dangers of "ploughing a rut" in any field of endeavour. We've all seen cases where unspoken assumptions come around to firmly bite someone on the arse. If and when that happens I strongly prefer it if it's not my assumption or my arse.

The regulation in germany (with it's reversible plugs) is even such that it's not defined which side is hot and which side is neutral on the outlet 
All the VDE "Verband Deutscher Elektrotechniker "-regulation says, it should be "the same within the whole installation" -
So the "it's per definition undefined" is deeply engrained here.

Generally I don't see the problem. It doesn't really matter if you are in a single phase installation with grounded neutral (TN), one where neutral is per definition ungrounded (TT) or undefined (IT) or even a two-phase system.

An appliance with a mains plug that becomes unsafe when plugged in the wrong way arround is something that is not permitted by all means. If you can plug it in both ways, it has to operate equally as well both ways.

Now, where is exactly the problem so many people have? The system doesn't allow to make any assumptions about one of the conductors being grounded in europe. Anywhere. Even where it's polarized. The only conductor that allows the assumption is PE.

This ^

The only stuff I'm aware of that carries a mains connection directly through to the chassis is some of that weird old hollow state gear.

We did things first and perhaps not the best but it is what it is.

Exsqueeze me? I don't think so.

https://en.wikipedia.org/wiki/Cragside
https://en.wikipedia.org/wiki/Electrification

[med6753]

There's a reason "All American 5" radios say for 120V DC or AC. Up until very recently places like lower Manhattan and I think San Francisco still supported DC for legacy elevator systems with DC motors.   

The London Underground is  a 4 rail system with  +420VDC and -210VDC.    The newer tube stock has 3-phase traction but the supply is still DC.


There are uninsulated telephone wires running along the driver side of the tubes.    Shorting the wires will de-energise that section of track and turn on the lights in the tunnel.

The trains have radios, so the telephone system is not used much anymore (I think)

-----------------------------------------------

The underground used to have its own power stations.   At least one is still around but modernised, for backup power. 


http://content.tfl.gov.uk/research-guide-no-30-lots-road-and-greenwich-power-stations.pdf

The NYC subway system plus 3rd rail operations into Grand Central Terminal are 600VDC. Not sure about other cities like Boston but wouldn't surprise me if they were DC too.

[Saskia]

A Dillon Aero is 48VDC. That's all you need

sorry, could not resist, me bad ...

In other news, an external Dolby C (Nakamichi NR 200) was waiting at my doorstep when I returned from my plumbing inspection today.
Bought via ebay classifieds to go along with that nice old Revox B77.

Oh wait, I still have that Sony Dolby C ... 
Need to get a second B77 then ... 

Zucca ??!!!
(just teasing ...)

[Cerebus]

I could be living in a Tesla Gigafactory and still only get permission for the smallest of rooms

Easy: Make sure the smallest room in your house is at least thirty square meters 

I am not making any smart comments here,
i am on the attic with my heater and vantilation system 
but i am allowed to buy stuff when she not finds out.

Is that your way of saying that you have waited at the corner of your street to see SWMBO go out before you've gone into the house with that impulse purchase of test gear you made while you were out? 

[med6753]

We did things first and perhaps not the best but it is what it is.

Exsqueeze me? I don't think so.

https://en.wikipedia.org/wiki/Cragside
https://en.wikipedia.org/wiki/Electrification

I stand corrected. Lots of good stuff I never knew. We just plain fucked up because we thought Edison was a god.

[Cerebus]

There's a reason "All American 5" radios say for 120V DC or AC. Up until very recently places like lower Manhattan and I think San Francisco still supported DC for legacy elevator systems with DC motors.   

The London Underground is  a 4 rail system with  +420VDC and -210VDC.    The newer tube stock has 3-phase traction but the supply is still DC.


There are uninsulated telephone wires running along the driver side of the tubes.    Shorting the wires will de-energise that section of track and turn on the lights in the tunnel.

The trains have radios, so the telephone system is not used much anymore (I think)

-----------------------------------------------

The underground used to have its own power stations.   At least one is still around but modernised, for backup power. 


http://content.tfl.gov.uk/research-guide-no-30-lots-road-and-greenwich-power-stations.pdf

I knew about Lots Road for a long time, but it was in a bit of London that I never seemed to have cause to go to. Then one day I had to go somewhere in Chelsea and turned a corner and found myself walking alongside Lots Road power station. Man that place was BIG, the power station site was almost a 1/4 mile long just judging from walking the length of it (I used to live in a road that was exactly 1/4 mile long in a straight line, so I have a built in gauge for a walked 1/4 mile). For all its size, the place managed to be inconspicious unless you were next to it.

[AVGresponding]

I stand corrected. Lots of good stuff I never knew. We just plain fucked up because we thought Edison was a god.

He was a brilliant engineer, sadly also a brilliant liar (pr, marketing etc) and greedy bastard. Tesla was a brilliant engineer, but not as good at lying, which meant he had a harder time fleecing money out of investors.

[Cerebus]

Just to get a scale of Lots Road power station, here's a side on view of the main engine hall from a side road. That building is about 200 yards long, plus there's another 50-75 yards of site at least at either end.

[Specmaster]

I was getting involved with Lots Road with LUL just before I retired, but I'm not sure if the project ever came to fruition following my retirement.

[med6753]

I stand corrected. Lots of good stuff I never knew. We just plain fucked up because we thought Edison was a god.

He was a brilliant engineer, sadly also a brilliant liar (pr, marketing etc) and greedy bastard. Tesla was a brilliant engineer, but not as good at lying, which meant he had a harder time fleecing money out of investors.

I'm not so sure Edison was a "brilliant engineer" either. What he WAS good at was stealing inventions from his subordinates and claiming them as his own.

[bd139]

Management material then 

[mnementh]

   https://a360.co/37CE8El   

Today's Project: Cheap RF Active Probe...

For those who are interested, I've posted the usual 3DP Nerd Stats along with assembly details and a ZIP including both .F3D and .STL files for this project in the 3DP thread:

https://www.eevblog.com/forum/3d-printing/3d-printer-yet/msg3623898/#msg3623898

mnem
 

[Cubdriver]

I stand corrected. Lots of good stuff I never knew. We just plain fucked up because we thought Edison was a god.

He was a brilliant engineer, sadly also a brilliant liar (pr, marketing etc) and greedy bastard. Tesla was a brilliant engineer, but not as good at lying, which meant he had a harder time fleecing money out of investors.

I'm not so sure Edison was a "brilliant engineer" either. What he WAS good at was stealing inventions from his subordinates and claiming them as his own.

He certainly fucked Tesla over.

-Pat

[bd139]

To be fair Tesla was a con man as well. Half his stuff was lies and overpromise or based on speculation.

Actually sounds like the modern namesake 

[Robert763]

The railways even have their own mobile phone system, GSM-R
It only cost £80,000 per user 
https://www.networkrail.co.uk/running-the-railway/gsm-r-communicating-on-the-railway/

[McBryce]

I could be living in a Tesla Gigafactory and still only get permission for the smallest of rooms

Easy: Make sure the smallest room in your house is at least thirty square meters 

I'm sure I don't need to tell you, but in Germany that can get pretty expensive. I live in a city, which usually makes things even more expensive. We have nine rooms in the house and the smallest (my lab) is just 4.5m². SWMBO says I'd just fill it with more test gear if I had more room, which is the equivalent of being told "things fall downwards" or "water makes things wet".

McBryce.

[bd139]

The railways even have their own mobile phone system, GSM-R
It only cost £80,000 per user 
https://www.networkrail.co.uk/running-the-railway/gsm-r-communicating-on-the-railway/

Wow that's a fucking shit show. Especially the nature of the problem:

Previous radio driver-signaller communications relied on analogue radio networks. These had limited functionality and had become increasingly expensive to maintain.

Yeah yeah yeah give it a couple of decades and the analogue stuff will be cheap as chips in comparison.

[Zucca]

Zucca ??!!!
(just teasing ...)

Hey Sas, I just pulled from evilbay a Rohde NT-2A for my YT production... now hunting a Focusrite 2i2.
As for now my audiofool budget is vaporized .... do not tease me, I need money to feed my son now...

[mnementh]

I stand corrected. Lots of good stuff I never knew. We just plain fucked up because we thought Edison was a god.

He was a brilliant engineer, sadly also a brilliant liar (pr, marketing etc) and greedy bastard. Tesla was a brilliant engineer, but not as good at lying, which meant he had a harder time fleecing money out of investors.

I'm not so sure Edison was a "brilliant engineer" either. What he WAS good at was stealing inventions from his subordinates and claiming them as his own.

He certainly fucked Tesla over.

-Pat

It's Edison's fault. Had they obeyed Tesla and Westinghouse a bit earlier, they'd have a much better system today.

I don't think anything that treats Neutral and PE as similar would be to code anywhere. Not that it stops the hot air cost-cutters, though.

Edison just couldn't get over thinking in terms of DC. Motherfucker was much better at turning inventing into a factory than at actually inventing; also very good at shamelessly self-promoting and electrocuting small animals in public squares. 

Westinghouse had the right idea; turn Tesla's genius loose but hand the reins to Edison to ensure something useful and profitable was produced. Sadly, had they realized the true depravity of the slave-state economy/ideology they were birthing, I suspect even Edison would have balked.

mnem
*currently somehow home alone without wife or chiddlers*

Yeah, that was all alluded to in my post above. Tesla was the brilliant engineer and scientist; Edison plodded like a mule, but he was systematic and doggedly determined. These properties made Menlo Park a great place for him to work and to take credit for the talents of folks with a lot more genius and a lot more actual scientific chops than he had himself.

He created the world's first "Invention Factory", which was truly his greatest, most lasting invention: turning engineering and invention into something that could be hitched to a corporation. As bd said, natural management material.

Tesla worked with the man twice; first in his Edison Machine Works (where he made Edison's DC motors work properly, and probably came up with the principles by which his later induction motors worked) and later at Westinghouse's insistence on the Niagara Falls generator facility.

Tesla was brilliant when it came to anything relating to oscillation; from subsonics to ultrasonics to radio and even broadcast energy, which he proved possible to a small extent with a field full of neon bulbs sticking up out of the ground like potatoes at Wardenclyffe... but he at the same time stated he didn't believe in subatomic theory or flow of electrons as the basis of electricity.

He was also flaky AF, and hopelessly altruistic. His dreams of broadcast power were all about freeing humanity from drudgery; he sought to unleash us from our servitude to "The Machine".

Ironic that we now are all now ultimately enslaved by the energy industry in its many forms...

Tesla's assessment of Edison after his death was probably most telling:

"He had no hobby, cared for no sort of amusement of any kind and lived in utter disregard of the most elementary rules of hygiene ... His method was inefficient in the extreme, for an immense ground had to be covered to get anything at all unless blind chance intervened and, at first, I was almost a sorry witness of his doings, knowing that just a little theory and calculation would have saved him 90 percent of the labor. But he had a veritable contempt for book learning and mathematical knowledge, trusting himself entirely to his inventor's instinct and practical American sense."

In short, sortof like that episode where Homer Simpson decides to quit work and follow in Edison's footsteps...

mnem

[mansaxel]

Delta were always the people to go to for OEM embedded PSUs, if you didn't want to pay (TDK) Lambda prices. 

We had, at a previous employer, a long thread of discussions with Delta and Cisco around supplies that blew up from what looked like mains transients. Or simply being bad. This was the only Cisco PSU type that blew up. They ended up sending two german engineers from the ascom facility they'd bought out, who turned up with a Tek scope and a diff probe, put it on the mains, and in logging mode, and then we went for dinner. Many a good meal was had, and we did get some Kräuterschnaps too. Conclusions came after some time in a long and thorough report, and some extra mains filtering was implemented with external units. My guess is that they had a sour batch of MOV or similar transient suppressors, and did not really want to admit it.

But it was fun and I did learn a lot

[mansaxel]

Wouldn't it be better to do the reverse of what we sometimes had to do with American equipment, and have a 120 to 240 step up transformer and fit special polarised sockets that the transformer(s) are plugged into in order to ensure that the neutral is just that?

"The neutral / phase position is undefined wrt the device" is IMNSHO a much better and safer position to take. And, as has been noted upthread, since Zuccas devices are Schuko-plugged, they come  with the "undefined" un-assumption built in, so they'll have been tested for "undefinedity" frequently.

[Robert763]

Cheap boxed HP 10544A OCXO on ebay UK for any budding time nut or as counter upgrade
www.ebay.co.uk/itm/224566128610
£25 inc post BIN and looks well made.

[bd139]

Cheap boxed HP 10544A OCXO on ebay UK for any budding time nut or as counter upgrade
www.ebay.co.uk/itm/224566128610
£25 inc post BIN and looks well made.

Gone

Edit: yes it was me. Thanks for the heads up

Considering a matching low ball bid on https://www.ebay.co.uk/itm/114903265366 now as well 

[Cerebus]

Cheap boxed HP 10544A OCXO on ebay UK for any budding time nut or as counter upgrade
www.ebay.co.uk/itm/224566128610
£25 inc post BIN and looks well made.

OK, which of you bastards had that out from under my nose? 

My mouse was moving to the "Buy It Now" button when the listing changed to "finished" in front of my eyes.

Edit: Ha! Now I know.

"Darling, I've got to go out for a bit." 
"Twickenham."
"What clanking sound?"
"Yes, I do need to take the last two rolls of gaffa tape with me."