Test Equipment Anonymous (TEA) group therapy thread

[med6753]

There are three resistors between unregulated and regulated paths (R676-678). Two at 47 ohms and one at 5K. Can stick voltmeter across one of them (probably one of the 47 ohms ones as they are connected to the regulators cathode) as a current sample. V/R=I. Then double that as there are two to get the current.

Good idea. And those two 47 ohm resistors are the pair that burn up when a short occurs.

[BU508A]

There are three resistors between unregulated and regulated paths (R676-678). Two at 47 ohms and one at 5K. Can stick voltmeter across one of them (probably one of the 47 ohms ones as they are connected to the regulators cathode) as a current sample. V/R=I. Then double that as there are two to get the current.

Good idea. And those two 47 ohm resistors are the pair that burn up when a short occurs.

Then I would connect a meter over both of them. A voltage of around 30 to 40 Volt I would consider as a safe state.
If the voltage is increasing significantly, I'd power off it immediatly.

[med6753]

Smart cookie you are. I give you props. 

6.31/47 = .134 times 2 = 268mA. Close enough. 

[Cerebus]

Outside my budget but 60V 120A module fitted and was recently in Calibration if anyone is in the market for one. eBay auction: #294326799480

@Mnem - Just how quickly would you like to charge your LiPOs? 

[Zucca]

Two major changes since my return:

1) This thread is sticky
2) This thread is moving so so fast, avalanche effect.

[Cerebus]

Call me impressed with Chinese Engineering for today at least on my recent XY Table buy. $160AUD or under $120 USD delivered from within Oz got me 20kg of very nicely machined Cast Iron, Hardened Gibb Adjusters and double thrust bearings on the screws  Haven't checked the backlash yet but very low even on a 4mm pitch lead.

Somewhere in there is a Reseller margin, Aliexpress fees, shipping from china then freight to me from 1000km away on Toll. 

I've been eyeing up those cheap XY tables. I'd be interest in both:

• Enough info to differentiate which of the various models on offer that is.
• Your findings once you get it onto the surface plate and give it a proper work-over. Oh, and what it's like in use. 

[bd139]

Two major changes since my return:

1) This thread is sticky
2) This thread is moving so so fast, avalanche effect.

To be fair I think this thread has evolved into its own forum at this point 

[psykok]

What is the general consensus about this boot anchor, how low should I go  ?

https://www.ebay.de/itm/124844098849

Interesting item, but the price tag is defective.

just sold mine for half  this price

[Cerebus]

PS: No, you can not buy Invar rulers:  36% nickel would give you allergy in no time.

So what? One ought to be wearing white gloves to make measurements anyway. 

[Cerebus]

Nah, that's not the real thing.

Also, as I commented on the video, a clock that does not talk NTP or PTP (and no %&€&%(#"%€ SNTP, if I may, please. ), or has a GNSS rx, should at least have a 10MHz/1PPS ref input so it'll actually show the time instead of an opinion. Seriously underwhelmed by most such designer efforts.

Fully agree. My (diy) clocks usually understand DCF77 (built-in receicer or input for demodulated pulses), my proprietary CAN "homebus" protocol, GPS PPS + NMEA, or NTP (broadcast by a local server).

Right on brothers! I mean, if it's more than ±100ns from UTC can you really call it a clock? Amiright, eh? 

[BU508A]

Two major changes since my return:

1) This thread is sticky
2) This thread is moving so so fast, avalanche effect.

1) Yes. We are sticky AND famous now at the same time. Except bd139. He was already sticky. 

2) Then I suggest you should become a zener diode. Could probably help you, then. 

[Specmaster]

Nah, that's not the real thing.

Also, as I commented on the video, a clock that does not talk NTP or PTP (and no %&€&%(#"%€ SNTP, if I may, please. ), or has a GNSS rx, should at least have a 10MHz/1PPS ref input so it'll actually show the time instead of an opinion. Seriously underwhelmed by most such designer efforts.

Fully agree. My (diy) clocks usually understand DCF77 (built-in receicer or input for demodulated pulses), my proprietary CAN "homebus" protocol, GPS PPS + NMEA, or NTP (broadcast by a local server).

Right on brothers! I mean, if it's more than ±100ns from UTC can you really call it a clock? Amiright, eh? 

Nope, its just a clock that is not correct 

[Specmaster]

Two major changes since my return:

1) This thread is sticky
2) This thread is moving so so fast, avalanche effect.

1) Yes. We are sticky AND famous now at the same time. Except bd139. He was already sticky. 

2) The I suggest you should become a zener diode. Could probably help you, then. 

[Cerebus]

DHL came a day early - I had Thursday as my notified delivery day!



I have chores to do - today domestic shopping, tomorrow getting my accounts up to date so the accountants can get my VAT return in on time. So little prospect of a proper play until Friday;  I think I want my first attempt at placing and soldering a 0.5mm pitch, 2.5x3.5mm QFN to be in daylight. My current thinking is that I reckon I've a 50% chance of consistently getting what I'd regard as an acceptable result.

I must admit to still being a bit stunned that good ole 74 series logic is available in such tiny packaging. I wonder if anyone has taken a old design that was made for 74 series in DIL packaging and produced a fully working scale model in QFN packages? That could be quite fun. One of the first minicomputers I used was four boards that fit horizontally into a 19" rack - so probably a board size of 16" x 12" something like that. The CPU was one board, memory another, with one board as a channel interface to an ICL 1900, and a final board with serial ports to connect to a statistical multiplexer that had a whole bunch of RS232 terminals handing off it. The whole thing apart from the memory was 74 series logic in DIL packages. You could probably shrink those boards to, say, 100mm wide quite easily.

[tggzzz]

Nah, that's not the real thing.

Also, as I commented on the video, a clock that does not talk NTP or PTP (and no %&€&%(#"%€ SNTP, if I may, please. ), or has a GNSS rx, should at least have a 10MHz/1PPS ref input so it'll actually show the time instead of an opinion. Seriously underwhelmed by most such designer efforts.

Fully agree. My (diy) clocks usually understand DCF77 (built-in receicer or input for demodulated pulses), my proprietary CAN "homebus" protocol, GPS PPS + NMEA, or NTP (broadcast by a local server).

Right on brothers! I mean, if it's more than ±100ns from UTC can you really call it a clock? Amiright, eh? 

It just means the display is more than 30m from the clock element (c~=1ns/ft)

[beanflying]

Call me impressed with Chinese Engineering for today at least on my recent XY Table buy. $160AUD or under $120 USD delivered from within Oz got me 20kg of very nicely machined Cast Iron, Hardened Gibb Adjusters and double thrust bearings on the screws  Haven't checked the backlash yet but very low even on a 4mm pitch lead.

Somewhere in there is a Reseller margin, Aliexpress fees, shipping from china then freight to me from 1000km away on Toll. 

I've been eyeing up those cheap XY tables. I'd be interest in both:

• Enough info to differentiate which of the various models on offer that is.
• Your findings once you get it onto the surface plate and give it a proper work-over. Oh, and what it's like in use. 

There is some 'reviews' on youtube but nothing that you would base this one is better than the other more a case of this thing X I brought is awesome/complete trash and I want to be heard. This evilbay/ali seller and gear badged Vevor tends toward better than average and I have brought a few things from them before but currently nil stock locally or in China.

Got it fully stripped down and most of the grease/rust preventative slime removed and tomorrow providing I don't die from my COVID jab I will finish the cleaning and put it on the granite in bits then assembled.

Table was claimed at X - 120mm and Y - 108 it is actually X - 125 and you can hit Y from +58 to -102 (total 160mm) and the beds still felt well locked into the gibbs at the ends. So while not huge certainly able to cover most projects with a single shift. Any larger and I will need to pull my finger out and rewire the 1000x600 2.2kW Router I have still waiting for attention

Also been looking at DRO's to eliminate the backlash thing entirely and that would make laying out patterns of holes much easier. Sort of $100 Aussie clams for the dirt cheap independent 2 axis option and $270 for the fancy glass scale 3 axis hole pattern generating option.

[Zucca]

I just found out I can order stuff from the 3D printing department in my new work:

- 3D SYSTEMS PROX 950
- F370 STRATASYS PRINTERS
- 3D SYSTEMS PROX 950

Hallelujah! Hallelujah! Hallelujah! Hallelujah! Hallelujah!
Hallelujah! Hallelujah! Hallelujah! Hallelujah! Hallelujah!
For the Lord God Omnipotent reigneth
Hallelujah! Hallelujah! Hallelujah! Hallelujah!
For the Lord God omnipotent reigneth
Hallelujah! Hallelujah! Hallelujah! Hallelujah!
Hallelujah! Hallelujah! Hallelujah! Hallelujah! Hallelujah!
Hallelujah! Hallelujah! Hallelujah! Hallelujah! Hallelujah!
Hallelujah! Hallelujah! Hallelujah! Hallelujah! Hallelujah!
The kingdom of this world
Is become the kingdom of our Lord
And of His Christ, and of His Christ
And He shall reign for ever and ever
And He shall reign for ever and ever
And He shall reign for ever and ever
For ever and ever, forever and ever
King of kings (Forever and ever Hallelujah! Hallelujah!)
And Lord of lords (Forever and ever Hallelujah! Hallelujah!)
King of kings (Forever and ever Hallelujah! Hallelujah!)
And Lord of lords (Forever and ever Hallelujah! Hallelujah!)
King of kings (Forever and ever Hallelujah! Hallelujah!)
And Lord of lords (King of kings and Lord of lords)
And He shall reign
And He shall reign
And He shall reign forever and ever
King of kings (Forever and ever)
And He shall reign (Hallelujah! Hallelujah!)
And He shall reign forever and ever
King of kings! and Lord of lords!
King of kings! and Lord of lords!
And He shall reign forever and ever
Forever and ever
Forever and ever
Hallelujah! Hallelujah!
Hallelujah! Hallelujah!
Hallelujah!

[beanflying]

Outside my budget but 60V 120A module fitted and was recently in Calibration if anyone is in the market for one. eBay auction: #294326799480

@Mnem - Just how quickly would you like to charge your LiPOs? 

That's a load not supply btw  Would handle most of my R/C fleet except the large helis and my F5 class stuff which is a few hundred amps.

[mnementh]

      https://www.amazon.ca/gp/product/B07GTD2JXP/

I'm likely to use either depending on what I have; tho I try to keep a sheet or two of these on hand at all times.

The emphasis on "try" there being because sometimes he wakes up in the middle of the night, mistakes it for chocolate and then all bets are off.

You would think so, but the smell of "cheap Chinese Rubber product" as you remove it from the baggie will remind you what it really is long before it gets anywhere your lips. 

Ah, eau de Harbor Freight.

Fortunately they are small mass and relatively large exposed area, so do air out and stop smelling like dragon farts quickly.

mnem
 

[Saskia]

quick update: received new hematology data today. Seems that the rapid weight loss coupled with exercise and extremely low carb had a positive effect on my prediabetes ...
blood insuline levels more than halved to about 7.7 down from 16, HBA1C constant at 5.5, blood sugar levels within normal parameters (< 100). Cardiologist said that I am on the right track and defeating the insuline insensitivity, thus preventing a type 2 diabetes.

Some good news for a change.

[mnementh]

[Much snipped for everyone's sanity...]

So when you said they were "loathed in here"... you were including yourself in that, but also trying to look at it from without at the same time...? 

No, I believe said "loathed here" speaking merely for myself.

I don't know how to answer that except to respond from experience with them I didn't really have a choice aboot.

I didn't say anything aboot crimp connectors in general; I was talking aboot JST-XH in particular.

I talked about having done lots of crimping, which you quoted, and then you said...

Then why the reluctance to use JST-XH?

The "then" being a connector, a "consequently", I read that as you thinking that my objection to JST-XHs was because they are crimped.

I know there are lots of cases where crimped cables simply are better, provided the crimping is done correctly. For making lots of connections, they are the only way to get through some projects without losing your mind from the drudgery of soldering a gazillion tiny connectors. You get to a point where it is likelier to fuck something up when soldering, and that has to be considered too.

I've literally been using them for decades in my RC gear; partly because everything comes with them, and changing to another connector would void any chance of warranty, but also because they get the job done. They are ubiquitous for a reason and they hold up much better in real world use under repeated mating cycles than they should. 

Nobody here has digits bigger or fatter than those on my big old hamhands; I handle the finished product without problem, as well as assembling them. Quite frankly, I prefer working with the crimps on these to those for DuPont connectors; they're easier to get in the crimper straight, and they're not nearly so finicky aboot an oversized wire.

If you need to solder near them on a PCB, the entire shroud can be slid up off the pins; sometimes this is a weakness as I have pulled the damned thing off a few times unintentionally. I will agree that it takes some care to not destroy them taking them apart and putting back together when they are new and tight, but if you do take care they still make reliable contact even after they work in.

You are making a choice for something that doesn't have to match a de facto standard as is the case with balance connectors, so I get wanting to go for something better. But for putting a lot of moderate current capacity connectors in a small footprint on a PCB, they're pretty hard to beat without getting into stuff so small you need to handle the bits with a magnifier and hemostats. 

But hey... you've probably made more such connectors than I've seen (rare enough that I can say that; usially it's me saying it to someone else ), so I'll defer to your superior experience.

It's just that IME, they aren't that horrible. I'd rather work with them than almost anything FPC or insulation-displacement, for example.

mnem
*toddles off to make some more wrong connectors*

My suspicion is that you find them less troublesome than I do because you get to use them on nice accessible things - dangling off battery packs or up in the open. My bias against them on an operational basis is running up against them in already constructed things made by other people with them placed in less accessible places - next to the edge of a case, or where you are having to reach around or under something to get to them. I find them almost impossible to manipulate reliably under those circumstances and I've heard that opinion voiced more than once by other people, so I'm not alone in thinking that. There was a thread a few weeks back about making tools to grip the receptacle. I think the fact that several people felt the need for a tool to use to disconnect them speaks volumes to my mind.

I got a mixed box of assorted JST-XH headers and receptacles a while back simply because I keep encountering things with them already installed and wanted some to hand for repair and adaptation. Assessing the design wasn't really on my mind when ordering them as repair stock, for that purpose it was merely enough that they fit. At the time of getting them I though that I'd probably end up using some for new construction but once I had them and had taken a good look up close and personal I changed my mind.

I can definitely agree about one thing, they are easier to crimp reliably than DuPont connectors. But then DuPont connectors, useful as they are, are the world's worst connector. Perhaps the original, genuine made by DuPont article is better, but what passes for 'DuPont' from most sources are horrible.

So... as usual when we have disagreement... mostly misunderstanding, plus a serving of "I just wanted something better".

Fair dinkum. 

mnem
 

[Zucca]

Städler 4B for the winners!

EDIT: Nobody can touch my Rotring 600. when my wife grabs it, my blood pressure increase.

[Andrew_Debbie]

. I hate shotgunning parts but I don't see any reason why those output transistors blew again. Tautech, you might be right about replacing those parts after all.

When I can't figure something out I blame the capacitors.   If I'm wrong, I don't tell anyone.   

[Cerebus]

quick update: received new hematology data today. Seems that the rapid weight loss coupled with exercise and extremely low carb had a positive effect on my prediabetes ...
blood insuline levels more than halved to about 7.7 down from 16, HBA1C constant at 5.5, blood sugar levels within normal parameters (< 100). Cardiologist said that I am on the right track and defeating the insuline insensitivity, thus preventing a type 2 diabetes.

Some good news for a change.

The problem with medical reports of biochemistry is that the buggers can't agree on what units to use, they vary from country to country and sometimes even between doctors/laboratories. There are four different ways of expressing HbA_1c results that are commonly used!

Fortunately it's one of the easier ones to guess, so your 5.5 is either 5.5% glycosylation or 5.5 mmol/L  - either way that is excellent news because neither of those is a diabetic or pre-diabetic figure, it's a completely normal healthy figure (unless some clever clogs has come up with yet another unit that I haven't heard of yet) and because HbA_1c is an indicator of medium term (roughly three months) blood sugar levels it means you've been "normal" for quite a while. Great news.

[Brumby]

Fired up things again to see how they trended - and set things up for the full 8 digits.  However, I had an unwelcome sight a few minutes in.

The display sat showing 1.3 - that's all - and the Gate LED was dark, but at least he decimal point was in the right place.  Ran through a few things, but nothing doing.  Walked away, muttering.

Ignored it for an hour then happened by and noticed it was now working as I expected.  About 10 hours in, it happened again for about half an hour - and then it was good again.  I also saw this once before, but it seemed to "go away".  Silly me.

OK, we have an intermittent ... hopefully resolved with a bit of card replugging and switch cleaning - but not tonight.

After several hours warming up, this is what I saw:



Occasionally, the last digit was a 2 .... and just as occasionally, it was a 0.  Aside from that little hiccup I mentioned, not looking too bad.