Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

https://youtu.be/0Qssr6B6MrU   https://www.adafruit.com/product/4600   

Oh, looks like this is what the Seeed Xiao was copying... do you have a AdaFruit vendor over there that's reasonably cheap? $6 for the Board, $1.25 for a 25Q16CT MB QSPI ROM chip.

Plug&Pray with all their I₂C Bus QT-series I/O.   https://www.adafruit.com/category/620   I know there's a 4MB chip (the 25Q32CT) that's a drop-in sub for this too; I've done it on some of my FC boards to add datalogging. Got mine coming. 

mnem
 

Interesting. Don’t think adafruit and cheap come in the same sentence  . To be honest I avoid the fuck out of their stuff as a whole. It’s a veneer of cutesy marketing over the ex MIT media lab shite pump usually.

Started looking at basic Cortex M3 devices now  . Moar Powah! 

Same here... but it is a good place to see what the "Maker" community is tinkering with now. I'm looking the exact opposite direction... smaller, simpler projects to learn on. Cheap-Cheap so I won't have to cry when I fry something. 

   

https://www.pjrc.com/store/teensy41.html          https://www.amazon.com/s?k=Teensy&ref=bl_dp_s_web_18229527011

Have you seen the PJRC Teensy4.1...? CORTEX M7 power for $27.  Teensy4.0 only $19.99.  Specs of all Teensy models here: https://www.pjrc.com/teensy/techspecs.html

mnem
 

[bd139]

I’m looking at stuff that runs Linux at the moment so a bit heftier 

[mnementh]

Oh, building your own PC from scratch, ehhh?

mnem
 

[bd139]

Close. Looking at these: http://www.wireless-tag.com/wp-content/uploads/2020/09/IDO-SOM2D01-Datasheet_EN.pdf

$10 bulk. Not sure what 1 off pricing is.

[Saskia]

@bd I could send you one. Fireproofed by AData 

[Saskia]

@bd could you not just use a Zynq SoC ? (forgive my ignorance)

[Cerebus]

@bd could you not just use a Zynq SoC ? (forgive my ignorance)

$10 bulk. Not sure what 1 off pricing is.

Cheapest Zynq that digikey has (XC7Z007S-1CLG225C) is £34.17.

[mnementh]

Close. Looking at these: http://www.wireless-tag.com/wp-content/uploads/2020/09/IDO-SOM2D01-Datasheet_EN.pdf

$10 bulk. Not sure what 1 off pricing is.

   https://www.amazon.com/FriendlyElec-NanoPi-NEO3-Rockchip-Computer/dp/B08D351484/

Hmmm... for that form-factor, the NanoPi Neo is a cheap dev board; especially if you need Ethernet onboard. If it might work, shop around... there are also Allwinner H5 variants if you don't like RockChip. Not sure if either are better or worse than BroadCom tho. 

mnem
 

[bd139]

I’d rather floss my nutsack with razor wire than use any Broadcom products 

[mnementh]

I have some in my backyard. Extra rusty just for you, bd. 

mnem
 

[bd139]

Yum tetanus time 

[mnementh]

Rusty Broadcom...? Tetanus will be the least of your worries.

mnem
It's all sand and rust.

[Saskia]

Preclean with capsaicin dissolved in campher oil. Put on youtube. Retire on the ad income.

[Specmaster]

Apparently MIT graduate can't do what I was doing at 4 years old.
 

Yeah that’s about right. It’s any university. So I did electrical engineering and we’re doing final year labs. Half the year only passed because they were associated with projects that were run by competent folk. In fact when doing team selection the tutors assigned no hopers to every team so that the average was good enough. I nearly cried when one of the guys on our team wired up a plug for the power supply, stuck live into earth and proceeded to zap himself and blow the bench RCD. Lucky fucker - they’d only just put them in. That was his only contribution to the project other than tea which was horrible. He got a 2:2.

Yeh, the real scary thing is that some of those graduates might well end as consultant engineers FFS.  A few years a go, I was working on the Royal Arsenal site in Woolwich (a massive site) and one of the consultant engineers involved on that project was trying to get the electrical contractor on the part that I was involved with, to run a 2 phase supply to a double socket in the flats, not a twin socket, a double. Bad enough taking it to a twin in a domestic environment, never a good idea even with adequate labelling to the effect that 415v was lurking within the socket box.

[Saskia]

I would not worry about those. I would definitely worry about your new k9 units.

[med6753]

Apparently MIT graduate can't do what I was doing at 4 years old.
 

Yeah that’s about right. It’s any university. So I did electrical engineering and we’re doing final year labs. Half the year only passed because they were associated with projects that were run by competent folk. In fact when doing team selection the tutors assigned no hopers to every team so that the average was good enough. I nearly cried when one of the guys on our team wired up a plug for the power supply, stuck live into earth and proceeded to zap himself and blow the bench RCD. Lucky fucker - they’d only just put them in. That was his only contribution to the project other than tea which was horrible. He got a 2:2.

Yeh, the real scary thing is that some of those graduates might well end as consultant engineers FFS.  A few years a go, I was working on the Royal Arsenal site in Woolwich (a massive site) and one of the consultant engineers involved on that project was trying to get the electrical contractor on the part that I was involved with, to run a 2 phase supply to a double socket in the flats, not a twin socket, a double. Bad enough taking it to a twin in a domestic environment, never a good idea even with adequate labelling to the effect that 415v was lurking within the socket box.

None of this surprises me. I've seen more than one engineer who were a danger to themselves and all others around them if you let them use a soldering iron. 

[med6753]

I won't be on Discord today. The Lady and I will be busy preparing our anniversary dinner together. Now this may or may not work out well because you have a cook and a non-cook. I'll let you judge who the non-cook is.   

There's a 50/50 chance I'll be banished from my own kitchen. 

[Robert763]

I once had a engineer who had been working for months on a aircraft electrical power budget app (spreadsheet) ask me why there was both 115V and 200V equipment on the same bus.   

[mansaxel]

Yeh, the real scary thing is that some of those graduates might well end as consultant engineers FFS.  A few years a go, I was working on the Royal Arsenal site in Woolwich (a massive site) and one of the consultant engineers involved on that project was trying to get the electrical contractor on the part that I was involved with, to run a 2 phase supply to a double socket in the flats, not a twin socket, a double. Bad enough taking it to a twin in a domestic environment, never a good idea even with adequate labelling to the effect that 415v was lurking within the socket box.

So it is true then!

I've been told that the reason a lot of entertainment gear racked and bolted together in the UK is single-phase up to insane size consumers, is that the common lore in them isles is that 415VAC is going to kill you more deader[sic!] than a meagre 240 will.

Therefore, even if not codified, a lot of gear and installs are made single-phase just because.

The amplifier racks for the Turbosound Flashlight system (which are unusually standardised for such a product) therefore come with a 32A mains plug, even if they're three-phase, simply so that you shall be able to feed them from a one-phase-to-three-phase adapter if you rent them back to the UK.

When we had a BT satellite truck for our contribution link to the UK when I worked with the swedish OB production of an ice hockey world championship back in ´96, it did take some work to power it, because it came with a 3-pin 32A mains plug. Not a 5-pin 16A. Because that would be Dangerous!

Hell, even 110 lukewarm 60Hz toy Volts will put a damper on your day in a most terminal fashion if you're unlucky. 415 is not much more dangerous than that. Dead is dead. End of story.

(Personal record: 405V system voltage,  315A fuse, very blown. I was not part of circuit.)

[salvagedcircuitry]

Got a pretty good deal on a 2ftx30ft spool of rubber ESD mat. My lab is getting a makeover 
Debating on cutting (2) 7ft esd mats or just running one long contiguous 14ft mat for my 2 side-by-side identical height tables.
Are there any downfalls of using one large mat over 2?

[factory]

It's upside down .... all the electrons will fall out!   

Here is the G.E.C. M.874B BW 421 resistance & capacity bridge back in the case & the right way round, testing one of it's original capacitors.


Apart from replacing a number of leaky wax or paper capacitors, I have made a new bracket to fit a fuse-holder, as this takes up some of the space that one of the HT capacitors filled, I've had to fit a smaller modern part instead.



I would like to leave the cable permanently attached, but the cover won't close with the lead & UK plug fitted, need to find an inline connector.


All the old capacitors.


This is probably the oldest item of TE I've repaired.

David

Edit 2024/05/13: added model/type number.

[Specmaster]

Yeh, the real scary thing is that some of those graduates might well end as consultant engineers FFS.  A few years a go, I was working on the Royal Arsenal site in Woolwich (a massive site) and one of the consultant engineers involved on that project was trying to get the electrical contractor on the part that I was involved with, to run a 2 phase supply to a double socket in the flats, not a twin socket, a double. Bad enough taking it to a twin in a domestic environment, never a good idea even with adequate labelling to the effect that 415v was lurking within the socket box.

So it is true then!

I've been told that the reason a lot of entertainment gear racked and bolted together in the UK is single-phase up to insane size consumers, is that the common lore in them isles is that 415VAC is going to kill you more deader[sic!] than a meagre 240 will.

Therefore, even if not codified, a lot of gear and installs are made single-phase just because.

The amplifier racks for the Turbosound Flashlight system (which are unusually standardised for such a product) therefore come with a 32A mains plug, even if they're three-phase, simply so that you shall be able to feed them from a one-phase-to-three-phase adapter if you rent them back to the UK.

When we had a BT satellite truck for our contribution link to the UK when I worked with the swedish OB production of an ice hockey world championship back in ´96, it did take some work to power it, because it came with a 3-pin 32A mains plug. Not a 5-pin 16A. Because that would be Dangerous!

Hell, even 110 lukewarm 60Hz toy Volts will put a damper on your day in a most terminal fashion if you're unlucky. 415 is not much more dangerous than that. Dead is dead. End of story.

(Personal record: 405V system voltage,  315A fuse, very blown. I was not part of circuit.)

Not quite like that, there are lots of incidents where more than 1 phase can be found in proximity to each other, BUT it should never happen in domestic installations where it is possible that a non-skilled / qualified person could interact with the system behind the fascia. If you really need to use more than a single phase in a domestic installation because load balancing etc, then the phases should never be mixed within the same room. In a commercial or industrial installation, where it is not expected that unqualified persons should be accessing the electrics, then it is permissible provided there is clear signage of the danger.

[Saskia]

then it is permissible provided there is clear signage of the danger. && no Electroboom.

[mnementh]

Screws for modding my drain-bamaged calculator have arrived, along with a few stowaways. Honest, no idea how those got in there... 

mnem
*toddling off to annoy people IRL/Discord*

[factory]

The HP 54615B from CDL arrived yesterday with no damage and no obvious signs of futzing, complete with horizontal rolling fault on the picture bulb. 


CAL switch wasn't in unprotected position on arrival, it's hard to tell from the listing picture or maybe they read here.


Some pictures of the insides which were cleaner than expected, mainboard with ST NVRAM module & Computer Products PSU module, I can only see one RIFA stinkbomb to replace. 



CRT monitor module is a Hitachi, but the picture bulb is Toshiba. 



I've replaced most of the larger capacitors on the CRT board, but as Shango006 often states it hasn't magically cured the fault yet. The horizontal hold control does work but it's impossible to get a stable display, currently looking at parts around the uPC1379C IC.


David