Test Equipment Anonymous (TEA) group therapy thread

[ch_scr]

8h temp sweep complete:

Something drifted, too early to tell what. Also, sweep is still faster than temperature response from DUT.
But script worked first try
Of course, upon closer inspection, it ended on time but not gracefully. Problem now fixed 
Edit: Also we can see little wiggles in the PID response on the temp controller from the 0.01K change every ~2s
The sweeps should have took 75 minutes but did take a little over a minute more -
the script is written right now in a way that the lag adds up with every step. Should be better implemented!
Also, another temp sensor on the DUT would be nice to have a more usefull XY plot.

[Specmaster]

The jokes aren't any better on Discord, unfortunately...   

Damn, missed it again, putting up the tree and the bulb for the fibre optics failed, took the base unit up to my lab, plugged it into my bench power supply, replaced the lamp, but the motor for the colour wheel stopped working, everything checked out on the meter though, but no go with the meter. So started looking online for a new tree, nothing really doing, resigned myself to getting out the old-fashioned light sets for the tree. Then it hit me like a lead balloon, the motor wasn't working because the motor was needed AC, and I was feeding DC, bleeding idiot me, plugged into the tree wall wart, and it worked perfectly. 

[mnementh]

I haven't yet reached the strata most likely to contain a Christmas tree in my current archaeological digs. 

mnem
I do at least have a wreath on the door, however.

[m k]

I think I've done my international freight support part.

https://4gte.com/products/hp-agilent-3469a-multimeter/

[mansaxel]

Yebbut... When you use that one, you can't count higher than 10 widdout taking off your shoes... 

I can. Considerably higher. To 32 using one hand, actually.

Just tried. It gets really hard (right handed) at 8.

Yes. It also does not help that I'm the only one in the family not suffering from joint hypermobility syndrome, and contorting the fingers to say decimal 12, using the pinky as MSD(igit) takes some effort. (left memory buffer). Especially zeroing out parts of the buffer is hard.

[mansaxel]

I haven't yet reached the strata most likely to contain a Christmas tree in my current archaeological digs. 

mnem
I do at least have a wreath on the door, however.

The official story is that we're off to the Bauhaus store for one (live one, if it's not a real tree, there is no point in having it) today, and that will be the cover too, as we're shopping new office chairs for the children. An IKEA office chair is a lot sturdier, better built, higher quality parts, and much more comfortable, than one of those "Gaming chairs" kids are being fooled into wanting. Also, the IKEA is half the price.

[med6753]

No tree here. Don't decorate. In fact, don't even own any Christmas decorations. Can't be bothered.

Humbug. 

[AVGresponding]

No tree here. Don't decorate. In fact, don't even own any Christmas decorations. Can't be bothered.

Humbug. 

Same here.

[Robert763]

Having recovered from the 'flu and caught up with other stuff, I had another go at the Delta Electronika SM1540D bench PSU last night. The later schematics that Delta provided is a great improvement. It addition to matching the unit, the layout has been improved so you can follow the circut "flow" much more easily. There is no circuit description so it's work it out as you go along. To recap (no not that)  It came in dead. So far a missing fuse, shorted (tracked) 100pF 1kV ceramic (known fault according to Delta. I put a 3kV one in) and open circuit contact on local / remote switch were fixed. Now it was lighting up but no output. The 100pF cap was killing the auxillary DC supplies. This is a small independent switch mode supply. So now we have Over Voltage Protection LED and CV mode LED ON. No signal to the main switch drive circuit. The OVP LED actually covers multiple faults so a bit of a pain.
The first significant component in the control loop is a HEF4046 PLL IC. On the original schmatic the function of this wa not at all clear. On the new schmatic it is apparent that it is generating a 50% duty cycle "clock" for the main power switcher that is phase locked to the PWM signal of the auxillary supply switcher. The 4046 VCO had no output. It was replaced and gave a nice output but still no drive. Next in line was a MOSFET lnverter / level shifter. Common source with pull-up to 12V on Drain. Drain stuck at 12V. The trusty Peak Atlas confrmed a dead small signal MOSFET. It's a BS170. I didn't have one in stock. A close match that I had was a VN10KM. Checking the datasheets showed a diference in pinout. So when fitting it I checkedthe track layout to be sure. Something seemed wrong so I double checked. The latest BS170 / MMBF170 daasheet on the ONSEMI website (https://www.onsemi.com/pdf/datasheet/mmbf170-d.pdf ) dated Dec 20121 has the wrong pinout for the BS170 
I've let them know.
So the VN10KM fitted (identical pinout) and we have life  . The output is on, sets correctly and tranfers from CV to CC as expected. However the OVP LED is still on, the CC LED does not come on and the CV LED only dims slightly on transition from CV to CC operation.
So investigation of the LED drive logic is for later today. I'm happy that the power circuit is functioning for now. Been a while since I've had a unit with so many individual confirmed failed components.

[Specmaster]

No tree here. Don't decorate. In fact, don't even own any Christmas decorations. Can't be bothered.

Humbug. 

Thats why I like Fibre Optic trees, no threading lights through the bleeding thing, just fluff out the branches, drape some tinsel round it and hang a few ornaments on it, job done and changing light show to boot, lovely. 

[mansaxel]

No tree here. Don't decorate. In fact, don't even own any Christmas decorations. Can't be bothered.

Humbug. 

Indeed. If I could escape it, I would.

[AVGresponding]

Ebay picks time:


Nice Bert scope, still haven't found an Ernie one to go with it: https://www.ebay.co.uk/itm/203752108423





Nice LCR meter from the rude named manufacturer: https://www.ebay.co.uk/itm/324944893072





May be worth an offer if you live near Oxford: https://www.ebay.co.uk/itm/133963568864





Hmmm, no thanks, but I'm sure someone likes these: https://www.ebay.co.uk/itm/154752320921





Will be interesting to see how the bidding goes on this. I suspect a late flurry of madness: https://www.ebay.co.uk/itm/144336702440





What's better than a 2465B? A 2467B. It's 2 better...  https://www.ebay.co.uk/itm/224748130361





Would be a decent BIN price, if it were one meter, and not put together from the remains of others...  https://www.ebay.co.uk/itm/133967798060





Here's one for Specmaster to salivate over, nice low start price: https://www.ebay.co.uk/itm/324948140926

[factory]

Someone's going to very disappointed if they bought this thinking it was a "5245L" and didn't look closely at the pictures. 
https://www.ebay.com/itm/115130981354



It does have some pictures showing what's on the inside of the lower specced 5246L, six digit display is standard on these (labelled option 01 on the back, which would be 7 digits, but clearly missing) and no fancy oven oscillator, just a crystal (5232A-69A) in an insulated can.


David

[Neper]

Indeed. If I could escape it, I would.

We used to, for many years.

Now, it's the damned virus plus the fact that our favourite spot in the North of France is also the favourite spot of the migrants and our idea of a Xmas holiday is taking photos around the harbours and beaches of the area. Nothing like listening to the carols from King's College on Xmas Eve in front of the blast furnaces in Dunkirk.

https://www.fotocommunity.de/photo/ein-lichtlein-brennt-fotoralfbe/29828047

Not this year, though...

[Specmaster]

Ebay picks time:

Here's one for Specmaster to salivate over, nice low start price: https://www.ebay.co.uk/itm/324948140926

Hmm, not bad, in my watchlist already, the biggest problem with it is the bleeding power switch on the back of the unit FFS.

[Specmaster]

Well I never expected that there would be quite so many Bah Humbug its bleeding Christmas folk on here. What were you all like as a child, didn't you look forward to Christmas then either?

I can understand the lack of enthusiasm for the commercial aspect of it but the actual decorating, especially the tree and lights I've always enjoyed that part of it 

[Neper]

The bestest of all halves doesn't allow one because of the cats.

[xrunner]

Well I never expected that there would be quite so many Bah Humbug its bleeding Christmas folk on here. What were you all like as a child, didn't

This is probably a very bad topic for this thread. But since you ask, why would I look forward to something I don't believe in? Sure as a child I did, but as a child we don't have the training to critically think about these things. That's all I should probably say ...

[Specmaster]

The bestest of all halves doesn't allow one because of the cats.

My cats used to like sitting under it. Never had any trouble with any of my cats wanting to climb the tree, we have trees in the garden they can climb if they want to.

[med6753]

I say humbug. Since it's just me why bother? Now I'll go to Son's with the grand kids and enjoy their tree and the decorations and such. So I'm not a total Scrooge. 

And in years past when I did decorate and put up a tree everyone was enthusiastic and helped out. But when it came time to take the tree down and put everything away they suddenly became ghosts of Christmas past and guess who was left holding the candy canes?

Humbug I say.     

[Specmaster]

Well I never expected that there would be quite so many Bah Humbug its bleeding Christmas folk on here. What were you all like as a child, didn't

This is probably a very bad topic for this thread. But since you ask, why would I look forward to something I don't believe in? Sure as a child I did, but as a child we don't have the training to critically think about these things. That's all I should probably say ...

I can understand that, but here's the way I view it, I'm big on religion at all, I don't go to church and I have an open mind on religion, just as I have on most things that cannot be simply explained / demonstrated. I view this time of year as more of a family time, no work etc, just good old family face to face time and the decorating thing is just part of that to me.

[Specmaster]

I say humbug. Since it's just me why bother? Now I'll go to Son's with the grand kids and enjoy their tree and the decorations and such. So I'm not a total Scrooge. 

And in years past when I did decorate and put up a tree everyone was enthusiastic and helped out. But when it came time to take the tree down and put everything away they suddenly became ghosts of Christmas past and guess who was left holding the candy canes?

Humbug I say.     

I just wish the putting the tree up etc was just as quick as taking it down though

[Neper]

I just wish the putting the tree up etc was just as quick as taking it down though

Ikea's advertising tells us the Swedes just throw them out of the window.

[med6753]

I say humbug. Since it's just me why bother? Now I'll go to Son's with the grand kids and enjoy their tree and the decorations and such. So I'm not a total Scrooge. 

And in years past when I did decorate and put up a tree everyone was enthusiastic and helped out. But when it came time to take the tree down and put everything away they suddenly became ghosts of Christmas past and guess who was left holding the candy canes?

Humbug I say.     

I just wish the putting the tree up etc was just as quick as taking it down though

Lady Cop is Ms Scrooge and she doesn't put up a tree or decorate either. And she has all that stuff. Packed away and in her words that's where it's going to stay. She even takes it a step further and hates wrapping presents and you get your gift naked. 

[Ice-Tea]

naked

There's worse things.