Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Well the weather people got it wrong. Yesterday's "big snow storm" was a dud. Perhaps 3 inches of actual snow followed by sleet. So the snow has a crust on it. Just enough to make the morning commute somewhat messy and a slow go. The police/fire scanner had few accidents so most were being sensible and slowing down.

But there's always those clowns who think because they have a 4WD Jeep they can drive normally. One of the accident calls was "Jeep stuck in a ditch".         

[AVGresponding]

I had one of those kits back in the day at work.  Until I lent it to someone and half of it's components went missing.

I hope you ensured that half the components of their office chair went missing also!

[TERRA Operative]

Replacement DS1486 NVRAM built, waiting on RAM chips for the DS1250Y, I just hope I got the layout correct... These PCB's were pricey due to the 0.2mm spacing...

c/w bonus fingerprint on the cell...

Did you use rechargeable coin cells?

Nah, just primary cells. The controller chip has no provision for charging, only balancing what cell to use.

[Vince]

Transformers : thanks for your inputs.. or maybe not, because if I stitch all of your replies together, they amount basically to keeping all of them ! Back to square one ! 

I hate you.

Maybe I will have better luck with the next items to sort... coming soon.

[Cerebus]

Transformers : thanks for your inputs.. or maybe not, because if I stitch all of your replies together, they amount basically to keeping all of them ! Back to square one ! 

I hate you.

Maybe I will have better luck with the next items to sort... coming soon.

Well our collective advice can't add up to "keep them all", unless Saskia hasn't had her say yet ...   

[Vince]

You mean she hates transformers ? That much ? I hadn't gathered that yet... but I have not been here for all that long so...

If so then yes, would be great to have her in put on the subject 

[Brumby]

I don't think I want to look at my box of transformers... 

[Cerebus]

You mean she hates transformers ? That much ? I hadn't gathered that yet... but I have not been here for all that long so...

Erm, no, it's more that she has a certain relish for a particular method of disposing of anything unwanted or troublesome. The solution often seems to come either in 50 gram packages, or with orbital velocity ...

[Robert763]

Only a box?
I have at least 5 Really Useful Box shallow tray type bins of just toroids. And a 19l one just for un-cased Variacs. I have 7 cased Variacs.  Found a 36.5V 25A C core transformer at the back of the garage too. 
On Vince's question my basis is

Don't keep ANY SMPS transformers (possible exception would be one made with a marked, known, core and has not been glued or potted.)
Don't keep any unmarked "consumer" grade transformers.
Keep any marked commercial / industrial transformers especially toroids and those from know manufacturers.
For CRT flyback I'd keep a couple if they have separate HV windings. An external rectifier is bonus too.
 

[m k]

I've tried to keep mine in the case or connected to something indicative.
So no flybacks but one Fiskars UPS 08.

BTW,
heh, variac size.

[Vince]

You mean she hates transformers ? That much ? I hadn't gathered that yet... but I have not been here for all that long so...

Erm, no, it's more that she has a certain relish for a particular method of disposing of anything unwanted or troublesome. The solution often seems to come either in 50 gram packages, or with orbital velocity ...

Ah didn't think of it this way ! But yes I had gathered her explosive activities by now...
However all these transformers are a bit heavy so not sure her amateur rockets would have enough grunt to take them to space... but it might be powerful enough to propel them a hundred meters high, then all the transformers would fall back like a shower, scattering all over the neighbourhood and puncturing every body's roofs... that would not make me very popular in the street  I fear ! 

[Vince]

Only a box?
On Vince's question my basis is

Don't keep ANY SMPS transformers (possible exception would be one made with a marked, known, core and has not been glued or potted.)
Don't keep any unmarked "consumer" grade transformers.
Keep any marked commercial / industrial transformers especially toroids and those from know manufacturers.
For CRT flyback I'd keep a couple if they have separate HV windings. An external rectifier is bonus too.
 

I MUCH prefer this view, so since it goes my way, I will arbitrarily and without ANY bias... decide that I will do that ! 

Of course not getting rid of any torodals... these things have a special place in my heart. I have a brand new one my dad bought me 30 years so I could build my first own made adjustable linear supply... also bought me teh case, a couple 2,000 counts LCD displays, 4 ICL7106 A/D display driver chips... I guess 30 years later I now feel the need to finally build it ! 

Finding toroïdal transformers in salvaged stuff is uncommon though... the only one I got, was a huge "home cinema" amp... the worst Chinese crap I have ever seen. The build quality was lower than the cheapest crap I have seen in 30 years. I was stunned how cheap they managed / dared to make this thing ! It's a case where the sum of the parts is worth a lot LESS than the individual parts !

So I could salvage lots of cool components from the thing. A few beefy power resistor, and a huge .. toroïdal transformer. Not in the picture as I can't find it... as I said I probably threw it back then in one of my boxes full of scrap boards, it's buried in there and some day I will excavate it....

The two (identical) flyback I might be able to find specs or internal construction, since of course I know where they came from. My two Samsung Syncmaster 700p CRT computer monitors. The service manual is available and has all the schematics, so that might help.

Firefox does not like Toroïdal transformers (has no taste obviously), it's not a valid word in his view... 

[mnementh]

I had one of those kits back in the day at work.  Until I lent it to someone and half of it's components went missing.

I hope you ensured that half the components of their office chair went missing also!

That's more a "ensure half his digits go missing" scenario right there... 

mnem
Whaaaaat...? He can have them back... right after he returns the missing components.

[mnementh]

Transformers : thanks for your inputs.. or maybe not, because if I stitch all of your replies together, they amount basically to keeping all of them ! Back to square one ! 

I hate you.

Maybe I will have better luck with the next items to sort... coming soon.

Wait.... what...? I only told you to keep the big ones... and maybe one or two ferrite ones... and flybacks... 

mnem
*looks down, stirring floor with one beclawed toe*   "I tried to be good..."

[mnementh]

Only a box?
I have at least 5 Really Useful Box shallow tray type bins of just toroids. And a 19l one just for un-cased Variacs. I have 7 cased Variacs.  Found a 36.5V 25A C core transformer at the back of the garage too. 
On Vince's question my basis is

Don't keep ANY SMPS transformers (possible exception would be one made with a marked, known, core and has not been glued or potted.)
Don't keep any unmarked "consumer" grade transformers.
Keep any marked commercial / industrial transformers especially toroids and those from know manufacturers.
For CRT flyback I'd keep a couple if they have separate HV windings. An external rectifier is bonus too.

In all honesty, this was my reaction too.  But like I just said, I was trying to be good.

I'll take exception to your statement about "consumer" transformers... two consumer gadgets I love to rob transformers from are a) nukeboxen and 2) old stereos, even the bigger bookshelf "pregnant boombox" ones by AIWA, Panasonic and Sony, etc. Those always have a good 200-400VA continuous-duty transformer with two 25-60V secondaries. Perfect for making small homebrew linear power supplies, and if you like the result, you can turn it dual-output.

The nukeboxen transformers... ehhh... what can I say? Any way you power them, you can get into lots of interesting trouble. 

And then, let's not get started talking about my collections of wall-wart & power bricks (ranging up to 20V/12A) and my server PSU sickness, which I pared down to 2 102L storage tubs before the Great White North adventure... 

mnem
 

[mnementh]

...The two (identical) flyback I might be able to find specs or internal construction, since of course I know where they came from. My two Samsung Syncmaster 700p CRT computer monitors. The service manual is available and has all the schematics, so that might help.

While it might be an interesting experiment to recreate the HOT oscillator circuit from those monitors just for fun, honestly that doesn't drive them up to "interesting" output voltage/current. The "wrap a few turns around the ferrite" trick is tried and true HV tomfoolery for over half a century.

Just Google ZVS and you'll find a whole world of videos. Sadly, most are made by complete 1D10Ts (well, unless you're in the mood to laugh at someone else's pain;  then it's perfect Jackass material), but there are a few that actually have a clue and you can learn a lot about the mysterious world of HV voodoo from them. Even ElectroBOOM! can be a wee bit educational. 

Alternately, if you want to get really anal about it, you can identify the primary winding in the flyback, then drive it with a fluorescent ballast. This will generate some really interesting crackle, and some of the newer solid-state ones will actually current regulate so you don't burn shit up constantly.

mnem
*tzzzzzzzzzt*

[mnementh]

Well the weather people got it wrong. Yesterday's "big snow storm" was a dud. Perhaps 3 inches of actual snow followed by sleet. So the snow has a crust on it. Just enough to make the morning commute somewhat messy and a slow go. The police/fire scanner had few accidents so most were being sensible and slowing down.

But there's always those clowns who think because they have a 4WD Jeep they can drive normally. One of the accident calls was "Jeep stuck in a ditch".       

We had a legit 6 inches here... but I've been a bit busy being sick to give a fuck. I guess since I'm not going blerk! every few minutes now, I'll need to drag the snowblower out and clear things so wifey can go to the store...

mnem
Or maybe I'll wake the boi up and "supervise" him while he does it...

[med6753]

The range switch on the Type 105 is removed. What a chore.    Lots of pictures on all the interconnects I had to unsolder. It will be lots of fun putting it back in.

It's still not obvious as to why it's jammed. I have to disassemble the detent assembly off the main shaft. More later.

[mnementh]

Thanks for being the brave one and taking point on this misery, med. I know I'd probably put it back in the queue at least twice before actually tackling it... 

mnem
 

[mnementh]

My suggestion, given the symptoms, is before you go dismantling the switch sectors, try some heat right on the threaded area of the shaft carrier/bushing. As froze up as you say it is, my gut says aluminum oxide poisoning.

Oh, and mark the shaft and that switch sector you left on the chassis, so you know you have the right flat lined up when you reassemble. Tricksy little Tek... looks like it has two flats on that shaft, so could get it 180° out of phase...

mnem
 

[med6753]

I think the smoking gun lies with the detent ball assembly. Look at all the corrosion under that tab. If that little ball can't move it will jam the switch. Going to pull it apart.

[Cubdriver]

Good to know, Mike.  I haven't opened mine yet - maybe tonight.  Good luck freeing it up!

-Pat

[Robert763]

Only a box?
I have at least 5 Really Useful Box shallow tray type bins of just toroids. And a 19l one just for un-cased Variacs. I have 7 cased Variacs.  Found a 36.5V 25A C core transformer at the back of the garage too. 
On Vince's question my basis is

Don't keep ANY SMPS transformers (possible exception would be one made with a marked, known, core and has not been glued or potted.)
Don't keep any unmarked "consumer" grade transformers.
Keep any marked commercial / industrial transformers especially toroids and those from know manufacturers.
For CRT flyback I'd keep a couple if they have separate HV windings. An external rectifier is bonus too.

In all honesty, this was my reaction too.  But like I just said, I was trying to be good.

I'll take exception to your statement about "consumer" transformers... two consumer gadgets I love to rob transformers from are a) nukeboxen and 2) old stereos, even the bigger bookshelf "pregnant boombox" ones by AIWA, Panasonic and Sony, etc. Those always have a good 200-400VA continuous-duty transformer with two 25-60V secondaries. Perfect for making small homebrew linear power supplies, and if you like the result, you can turn it dual-output.

The nukeboxen transformers... ehhh... what can I say? Any way you power them, you can get into lots of interesting trouble. 

And then, let's not get started talking about my collections of wall-wart & power bricks (ranging up to 20V/12A) and my server PSU sickness, which I pared down to 2 102L storage tubs before the Great White North adventure... 

mnem
 

Ahh, one thing to remember is you are in 60 Hz land and we are in 50 Hz. Transformers that are OK at 60Hz can be marginal at 50Hz Most consumer tranasforers I've come across tend to desigined towards the 60 Hz end of the spectrum.

[Robert763]

I think the smoking gun lies with the detent ball assembly. Look at all the corrosion under that tab. If that little ball can't move it will jam the switch. Going to pull it apart.

I doubt it will be the detent.
Note that both the shaft AND bushing are Aluminium / light alloy. This is a very bad combination. Almost certainly the shaft and bushing have galled and effectively are welded together.
There is no practical fix for this. You need to get a new switch mechanisim and swap the wafers over.
A longer on cn be cut down. I have some if you are really stuck but postage is expensive these days.

EDIT link to galling description
https://www.twi-global.com/technical-knowledge/faqs/what-is-galling

[mnementh]

I think the smoking gun lies with the detent ball assembly. Look at all the corrosion under that tab. If that little ball can't move it will jam the switch. Going to pull it apart.

I doubt it will be the detent. Note that both the shaft AND bushing are Aluminium / light alloy. This is a very bad combination. Almost certainly the shaft and bushing have galled and effectively are welded together.
There is no practical fix for this. You need to get a new switch mechanisim and swap the wafers over.
A longer one can be cut down. I have some if you are really stuck but postage is expensive these days.

EDIT link to galling description
https://www.twi-global.com/technical-knowledge/faqs/what-is-galling

Robert, I was trying to give the guy hope... aluminum oxide poisoning can be heartbreaking in cases like this.     IME, heat is the only chance of freeing up such a victim.

mnem