Test Equipment Anonymous (TEA) group therapy thread

[Mr. Scram]

If anybody out there is, now or at any time in the future, designing something that needs an auxiliary battery "on board", please, please, please, consider relocating it to a little plastic container off the board and connecting to it with a little plug and socket. Yes, it'll add 50¢ to your BOM, but it will save your customers $$$ or €€€ in the long run when the battery eventually craps out. If you're feeling really considerate you could make that container leak proof, but at least put it at the bottom of the case (gravity wise).

Similar mechanical decoupling is done in many laptops by having the power receptacle as a separate unit instead of soldering it on the PCB. This allows both swapping out a defective port and ensures things don't break too quickly at the simian interface. It seems the advent of glued together computers and USB C charging is changing that, though.

[Specmaster]

CPAP machine anyone?

My neighbor got a new CPAP (continuous positive airway pressure) machine and the supplier said to throw this one away. He asked me if I wanted to play around with the old one (he knows me pretty well). Of course I do. It's a ResMed unit and the PCB says Sydney, Australia.

So what it does is give you positive air pressure in your airway all night. It has a control unit which has an SD card. The SD card appeared to have daily files on it giving the prescriber the data on the performance. In the control unit is a blower. The left side connects to the right side which has a water reservoir for humidity control. Then the air comes out a long tube to your mask.

The main unit has a menu system for some simple user settings, but there is no way to control the air pressure in the menu. He said they can do it in the office if needed after a sleep study. There is an interface connector on the back but not one I recognize. I presume that is where they connect an external computer or proprietary unit to set it up.

Some of the parts used, other than the usual suspects such as voltage regulators and the like -

stm32f103zgt6
ARM® Cortex®-M3 STM32F1 Microcontroller IC 32-Bit 72MHz 1MB (1M x FLASH

Sensiron sdp711-01 differential pressure sensor

GE NPA-C02035 Surface-Mount Pressure Sensor

On the top side of the PCB are a whole lot of gold pads, perhaps for testing? In the water reservoir unit is a humidity sensor that sends it's data back through the interconnect between units.

Right now it blows a steady stream of air and doesn't require the humidity unit to run. Might be useful for a project someday. 

Surely, that is essentially a ventilator? It would be my guess that those gold pads would for an automatic test machine to test the board after it was populated and soldered to see if it needed to go for reworking or not?

[Saskia]

probably. Or jtag access to program in circuit.

In other news I just brought some stuff upstairs that had been sitting in my garage since the last Reichelt trip which has been quite a while

a 0.8l ultrasonic and a USB microscope. While I don't trust that microscope a bit the price was hard to beat. The Ultrasonic is an Emmi that I wanted to use for cleaning small pcbs.
If there is interest I can certainly bring photos.

[URI]

OK, I'm out of here until May at the earliest.

 

I got my big boy pants on. As well as my walking shoes. And I'm voting with them. 

    

I also would prefer more on topic postings and less (but not none) pub talk..   
Be kind to each other, please!

[Specmaster]

probably. Or jtag access to program in circuit.

In other news I just brought some stuff upstairs that had been sitting in my garage since the last Reichelt trip which has been quite a while

a 0.8l ultrasonic and a USB microscope. While I don't trust that microscope a bit the price was hard to beat. The Ultrasonic is an Emmi that I wanted to use for cleaning small pcbs.
If there is interest I can certainly bring photos.

[Cubdriver]

probably. Or jtag access to program in circuit.

In other news I just brought some stuff upstairs that had been sitting in my garage since the last Reichelt trip which has been quite a while

a 0.8l ultrasonic and a USB microscope. While I don't trust that microscope a bit the price was hard to beat. The Ultrasonic is an Emmi that I wanted to use for cleaning small pcbs.
If there is interest I can certainly bring photos.

Saskia, do you really need to ask that??   

-Pat

[mnementh]

LOL! Beat me to it! 

mnem
 

[Saskia]

especially now, when we are on topic ?
right. Already working on it.

[psykok]

I happy to share the same illness

I mainly everything for the hp 331a

[BU508A]

You know it is a good day, when it's Mouser delivery day. 

Parts for my 10MHz distribution amplifier for the Efratom and
the parts for the LED bargraph thingie.

[mansaxel]

You know it is a good day, when it's Mouser delivery day. 

Parts for my 10MHz distribution amplifier for the Efratom and
the parts for the LED bargraph thingie.

Yes, I had my Mouser day last month. It is a good day. Whenever it happens.

Do you have a design for the DA to share? I've got Needs.

[capt bullshot]

corrosion here, corrosion there, corrosion everywhere ...

Oh well, the manufacturer of this device took care of a proper auto destruct.

[Saskia]

Ok, here's the Microscope. Branded Reflecta DigiMicroscope Flex, from the Reichelt returns bench. Price listed (as returns) 59€.

Small plastic gizmo with a flexible suction stand that attaches to a plastic board. Some foto capture software included. Pseudo magnification/zoom gizmo, lighting of the work area is hmmmmmmm.

results from hmm to unusable.
See for yourself.

Verdict:
This has to go. It will not stay here.

I will keep my trinocular amscope on da big booooom.

[Neomys Sapiens]

From the auction I mentioned....

A BWD 530A single channel oscilloscope?

Oh, OK......

A front panel which only a possum could love!

[Saskia]

Small tiny ultrasonic cleaner. NIB. From the returns bench. Sturdy, looks nice, for smaller projects that do not require the big one (the 10l gizmo is sitting here, as well ...)

This one may stay.

[tautech]

Small tiny ultrasonic cleaner. NIB. From the returns bench. Sturdy, looks nice, for smaller projects that do not require the big one (the 10l gizmo is sitting here, as well ...)

This one may stay.

Also good for brass cases. 

[worsthorse]

CPAP machine anyone?

My neighbor got a new CPAP (continuous positive airway pressure) machine and the supplier said to throw this one away. He asked me if I wanted to play around with the old one (he knows me pretty well). Of course I do. It's a ResMed unit and the PCB says Sydney, Australia.

So what it does is give you positive air pressure in your airway all night. It has a control unit which has an SD card. The SD card appeared to have daily files on it giving the prescriber the data on the performance. In the control unit is a blower. The left side connects to the right side which has a water reservoir for humidity control. Then the air comes out a long tube to your mask.

The main unit has a menu system for some simple user settings, but there is no way to control the air pressure in the menu. He said they can do it in the office if needed after a sleep study. There is an interface connector on the back but not one I recognize. I presume that is where they connect an external computer or proprietary unit to set it up.

Some of the parts used, other than the usual suspects such as voltage regulators and the like -

stm32f103zgt6
ARM® Cortex®-M3 STM32F1 Microcontroller IC 32-Bit 72MHz 1MB (1M x FLASH

Sensiron sdp711-01 differential pressure sensor

GE NPA-C02035 Surface-Mount Pressure Sensor

On the top side of the PCB are a whole lot of gold pads, perhaps for testing? In the water reservoir unit is a humidity sensor that sends it's data back through the interconnect between units.

Right now it blows a steady stream of air and doesn't require the humidity unit to run. Might be useful for a project someday. 

Surely, that is essentially a ventilator? It would be my guess that those gold pads would for an automatic test machine to test the board after it was populated and soldered to see if it needed to go for reworking or not?

A number of projects for turning CPAP machines into ventilators are in various stages of development. A couple of challenges: CPAP machines are expensive as a starting point unless the machines are donated, which raises the second problem: how do you vet a donated machine to be sure it is a good starting base for a ventilator?

The alternatives, like the MIT bag-to-ventilator project seem to be better solutions: cheaper, easier to test, easier to use, etc.  These are fascinating, and workable, alternatives that say a lot about the design, manufacturing, and marketing of medical devices.

But there's a more basic problem, as we have seen in the serological testing area. When the FDA makes the testing and approval cycle irrelevant grifters and frauds flood the market with shit that doesn't work. That's more than a "somebody got taken" monetary issue when the device or test in question may be a contributing cause to a serious illness or death rather than a preventative. That means, along with figuring out how to build inexpensive, easy to produce medical equipment, we have to figure out what sort of testing and certification is required so it doesn't kill a bunch of people.

[Cubdriver]

You know it is a good day, when it's Mouser delivery day. 

Parts for my 10MHz distribution amplifier for the Efratom and
the parts for the LED bargraph thingie.

Yes, I had my Mouser day last month. It is a good day. Whenever it happens.

Do you have a design for the DA to share? I've got Needs.

Mouser (or Digi Key) day is always good all around except for my credit card.  IT is not fond of Mouser or DK or eBuy days... 

-Pat

[Cubdriver]

Small tiny ultrasonic cleaner. NIB. From the returns bench. Sturdy, looks nice, for smaller projects that do not require the big one (the 10l gizmo is sitting here, as well ...)

This one may stay.

It's so cute!!  If you feed it, will it get bigger?

I was using mine over the weekend to clean some resin prints.  The beakers I'd ordered from Amazon had not yet arrived, so I put my cleaner into some plastic containers that had previously held nuts or chocolate raisins or the like.  Inside of ten minutes of operation, they had holes blown in them, as I discovered when I lifted them out of the water bath and they looked like a cartoon character that had just been machine gunned, shrugged it off, and then taken a drink of water.   

Of course the beakers showed up today, not that I'm done with it for now...   

-Pat

[BU508A]

You know it is a good day, when it's Mouser delivery day. 

Parts for my 10MHz distribution amplifier for the Efratom and
the parts for the LED bargraph thingie.

Yes, I had my Mouser day last month. It is a good day. Whenever it happens.

Do you have a design for the DA to share? I've got Needs.

Yes, sure. It's based on this Thread in the eevblog forum:
https://www.eevblog.com/forum/projects/made-a-nice-_home_-for-my-efratom-lpro-101/

A bit hard to find is this H11102NL signal transformer. I looked at Mouser and decided to use this one:
Pulse H6080FNL

[Saskia]

@Pat having a small one hath its advantages
I don't really NEED to get out the 10l ultrasonic when cleaning coils, the small one will do just fine.

I can separate cleaning cycles and cleaning solutions.
The small one can clean some brass casings whereas the big one cleans some stainless steel.
Or PCBs, or wiring harness, ...

[mnementh]

CPAP machine anyone?
(SNIP)
Right now it blows a steady stream of air and doesn't require the humidity unit to run. Might be useful for a project someday. 

Surely, that is essentially a ventilator? It would be my guess that those gold pads would for an automatic test machine to test the board after it was populated and soldered to see if it needed to go for reworking or not?

A number of projects for turning CPAP machines into ventilators are in various stages of development. A couple of challenges: CPAP machines are expensive as a starting point unless the machines are donated, which raises the second problem: how do you vet a donated machine to be sure it is a good starting base for a ventilator?

The alternatives, like the MIT bag-to-ventilator project seem to be better solutions: cheaper, easier to test, easier to use, etc.  These are fascinating, and workable, alternatives that say a lot about the design, manufacturing, and marketing of medical devices.

But there's a more basic problem, as we have seen in the serological testing area. When the FDA makes the testing and approval cycle irrelevant grifters and frauds flood the market with shit that doesn't work. That's more than a "somebody got taken" monetary issue when the device or test in question may be a contributing cause to a serious illness or death rather than a preventative. That means, along with figuring out how to build inexpensive, easy to produce medical equipment, we have to figure out what sort of testing and certification is required so it doesn't kill a bunch of people.

Precisely; especially since this exact sort of grift/fraud in the last such approval cycle is the reason the US (and Canada, indirectly) has a nationwide shortage of ventilators. A mass purchase was proposed, authorized, designed, & paid for during the Obama Administration. Then the bid winner was bought out by a larger competitor expressly to cannibalize that sale. Of course, those in the regi... err, administration which followed felt that our lack of a stockpile of lifesaving ventilators was not a priority... and the rest is history; which we are living through.

mnem
"May you live in interesting times." ~Ancient Chinese curse

[Neomys Sapiens]

@neomys sapiens checking if I can get the power supply you pointed out for a bargain.
And rearranging some computing stuff.

Did you look at the Heinzinger for which I had included an link earlier (Rosenkranz)? I find that generator knob very interesting. Also, I have to enquire whether it is remote controllable together with U/I. That would mean you get some PWM for free.

And I hope that the remark about computers is not aiming at me having noted a deficiency there. Because me and computers, that is a topic in itself. I still operate a W7 laptop as my current main system, but it will not cope properly with W10. When I looked what I should do next, I found that all newer Lenovo after my T60 are those blasted 16:10 things. It does not help me when working with documents, nor drawing nor anything else. And a new stationary PC? Those that are reliable and which I would like to get are industrial machines and they are either in the price range of a major aquisition or they have the same problem with W7. So I am still totally undecided what to do. And all that just that people can get visuals of a soricomorph in it's lab? Nah. Also I'm not keen to sanitize my home office just for that.
Does that Discord stuff work with audio only too - akin to Skype for Business?

[Saskia]

contact me via PN if you want something decent with W7. I am using W7 myself as I get into an uncontrollable rage when I have to use W10. Discord works fine with W7 and Audio.

[Cubdriver]

@Pat having a small one hath its advantages
I don't really NEED to get out the 10l ultrasonic when cleaning coils, the small one will do just fine.

I can separate cleaning cycles and cleaning solutions.
The small one can clean some brass casings whereas the big one cleans some stainless steel.
Or PCBs, or wiring harness, ...

Agreed - at some point I need to look for a small one.  I currently have a 1.5 gallon (~3.8l) unit, and it's kind of a PITA to set up for small things so it doesn't get used as often as it should.

-Pat