Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

At the risk of fanning the flames about an earlier debate that we had here about wire nuts v Wago devices, this video attempts to find out which is the better system. I apologise if this has already been posted, but as they say it's better to have it twice than not at all 

[Specmaster]

@med6753
Fine, yes, but it still beats the hell out of me as to how you can see the benefit of the seatbelt and yet cannot see the same benefit in trying to make sure that OTHER people can see you on the road. 

[mnementh]

So what's your take on the now-common practice of using Ux on the silk-screen to designate a dual-FET? I've not yet seen it in documentation, but I assume it will only be a matter of time... 

I personally feel that since we didn't start doing that for Darlingtons or FETs with a Diode/Resistor etc... we shouldn't do it for them either.   

I am decidedly undecided on this detail, as it would mean for me to decide which degree of integration and/or which number of elements would justify a change in the RD. But then I would strongly lean towards using A, not U.

U describes an integrated analogue circuit, thereby signifying that the elements making it up do perform their function together. Like, for example, you can't use a single transistor out of an average integrated OPA in any arbitrary function. The double FET, like the double BJT, is indeed a problem child. You could see it as an array of two, but no one is going to use it as such. For arrays of a greater number of transistors, like a CA3086, it becomes somewhat clearer. Here the chances are open on the use of the constituent transistors in the overall circuit.

The use of U tries to emphasise the application of a double transistor as a differential pair, which is admittedly the most often occurring one. But this is not an inherent characteristic, as you could use them for completely independent circuit functions.

But I welcome certainly any thought on this matter. Because well structured diagrams, of which reference designators are an inevitable part, are of utmost importance for electrical/electronical technology.
Just like the instruments, which are enabling us to observe it.

One of the places I'm seeing double FETs used a lot is in Lixx technology BMS PCBs, and another is  Lixx powered devices that have charge circuitry built-in. They are used to break the circuit in cases where more than one fault condition is being monitored for or to switch modes between charging the Lixx power source or drawing power from it; so ultimately sortof a high-current OR gate.

Looking at it that way, I guess the reasoning behind this use of the Ux nomenclature sortof makes sense... but I'm still not sure I agree that this use case falls on that side of the line. Mostly because I see it as just a slightly smarter pass element. 

mnem

[mnementh]

At the risk of fanning the flames about an earlier debate that we had here about wire nuts v Wago devices, this video attempts to find out which is the better system. I apologise if this has already been posted, but as they say it's better to have it twice than not at all 

Yeah, we already discussed this one.

Another WAGO apologist/fanboi video, it supposedly "makes a fair and unbiased comparison" yet when the WAGO doesn't prove itself superior by the video's own metrics, still extolls the virtue of the WAGO (mostly, that it is in fact the quick and lazy way to make the connection) anyways... 


Thanks but no thanks.

mnem
 

[BU508A]

Yes, saw it after my posting.
Was low on coffee, distracted and shooted at the first trigger. 

This is how one ends up shooting one's own toes off...

I think everyone here has had a similar experience.
Except the dragon, he has claws.

 

[BU508A]

At the risk of fanning the flames about an earlier debate that we had here about wire nuts v Wago devices, this video attempts to find out which is the better system. I apologise if this has already been posted, but as they say it's better to have it twice than not at all 

https://youtu.be/zgjo36-jaFY

I've posted this already here:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4006408/#msg4006408

 

[med6753]

I need a TE project....stat. 

Stepping away from the keyboard and going out for a walk.

No....it's not a long walk off a short pier although some of you might wish it is. 

[mnementh]

Good idea, old friend. 

mnem
Walkabout is always good for what ails ya.

[mnementh]

Yes, saw it after my posting.   Was low on coffee, distracted and shooted at the first trigger.     

This is how one ends up shooting one's own toes off...

I think everyone here has had a similar experience.  Except the dragon, he has claws.

Well, yes... but they are on fingers and toes.     And that's why I tend to avoid firearms... I know they are far likelier to harm me than anyone else. 

mnem

[mnementh]

I think some people in Oz are quite unaware of the existence of the rear fog light, & happily blind following drivers on clear nights, as they have never seen their car from the rear.

Yeah, I hate that.

mnem

[Brumby]

Yep!!   Now how do we send THAT to those who need it burned into their eyeballs?

[Specmaster]

At the risk of fanning the flames about an earlier debate that we had here about wire nuts v Wago devices, this video attempts to find out which is the better system. I apologise if this has already been posted, but as they say it's better to have it twice than not at all 

https://youtu.be/zgjo36-jaFY

I've posted this already here:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg4006408/#msg4006408

 

So you did, I thought I did see it before, but like I said, it never hurts to make sure 

[Specmaster]

Good idea, old friend. 

mnem
Walkabout is always good for what ails ya.

Hmm, maybe he is looking for a rope to piss up 

[TERRA Operative]

Well, the SG503 that I replaced the front panel on works great, except the 100-250MHz range...
It's range is currently low at 87.2-230MHz...

I've rebuilt the variable cap, replaced all the drifted parts with new, given is a spit shine, etc etc, but there isn't much adjustment for this range to bring it into spec.
One thing I think may be an issue is that I replaced some drifty carbon composite resistors but used metal film, so I'm wondering if they are messing things up with parasitic capacitance/inductance.
(R145, R146, R150 center left of the schematic)

I think I might try replacing them again but use large SMD resistors to get something more non-inductive etc. I'm pretty certain I don't have any 1/8W 51R carbon composite resistors in my stock, and the store in Akihabara with them only sells 1/4W and above from memory.

I also need to go get some realllly thick grease for the reduction gear assembly on the frequency adjustment dial, the thinner standard grease I used makes for a notchy feeling.

[PA0PBZ]

Well, the SG503 that I replaced the front panel on works great, except the 100-250MHz range...
It's range is currently low at 87.2-230MHz...

I've rebuilt the variable cap, replaced all the drifted parts with new, given is a spit shine, etc etc, but there isn't much adjustment for this range to bring it into spec.
One thing I think may be an issue is that I replaced some drifty carbon composite resistors but used metal film, so I'm wondering if they are messing things up with parasitic capacitance/inductance.
(R145, R146, R150 center left of the schematic)

That makes sense, they are part of the tuning circuit and adding inductance brings the frequency down.

[Neper]

Well, the SG503 that I replaced the front panel on works great, except the 100-250MHz range...
It's range is currently low at 87.2-230MHz...

Could it be that someone has deliberately modified the range so that it covers the entire FM broacast band without having to switch ranges at 100 MHz?

[Cerebus]

Nah, that's this car hahaha:

https://en.wikipedia.org/wiki/Nissan_Cube

Looks to me as a very close relative. 

Just goes to show that I'm years ahead of my time. I made one of those out of Lego when I was about five!


(A contemporary similar rendition.)

[TERRA Operative]

That makes sense, they are part of the tuning circuit and adding inductance brings the frequency down.

Yeah, usually most things are 'ok' with metal film replacements, but this is in the heart of a 250MHz oscillator, so probably pretty finicky. Tuning (for what adjustment there is) consists of stretching and squeezing a wire coil by fractions of a mm....

Could it be that someone has deliberately modified the range so that it covers the entire FM broacast band without having to switch ranges at 100 MHz?

It didn't look modified. From what I can tell, I'm the first one to poke my sticky little fingers inside there where I shouldn't. 

[mansaxel]

So you did, I thought I did see it before, but like I said, it never hurts to make sure 

I don't think this one's been posted:



Sums it up nicely. Stranded and solid is more common than you might think.

[mnementh]

   ...Damn car is like a Christmas tree. (Stock photo included)

Ah, the famous cube-on-wheels. 

Nah, that's this car hahaha:   https://en.wikipedia.org/wiki/Nissan_Cube

Looks to me as a very close relative. 

True, but the Nissan Cube is almost a perfect cube, and hence its name 

Long before any of these neo-cubist poseurs, there was... Step Van.   

mnem
"...they hung in the sky in much the same way that bricks don't." ~Douglas Adams

[Robert763]

Too late, Murphy did notice and Murphy agrees with me that DRL's are infact an important safety factor and if a car is built with them then they should never be disabled. It not as if you have to pay through the nose to have these switched on, they are not massively power hungry items.  Remember, they are for the benefit of other road users and if someone can see you clearly because of them it might save your life in return  because the other person didn't pull out of a side turning right into your path causing a crash, what ever next, refusing to wear your seatbelt? 

Even if you don't care about your safety as a result of being easier to spot, consider the other person and help to protect them as well, geez. 

If someone can't see this blue blob of an SUV under normal daytime conditions I have to question whether they should be driving at all. And in cases of inclement weather or night time I have the intelligence to use appropriate exterior lighting as necessary. I don't need to rely on a computer to make that basic decision for me. And.....to help insure I am seen when lighting is required I installed these auxiliary driving lights.

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight.
On diconnectting DRLs, if you have an accident involving visibility of your vehicle this might be used against you.

[m k]

If there is a need for maximum brevity, use BJT.

And Vince, don't you dare to name EITHER transistors OR transformers 'TR' in a circuit diagram!
On the topic of reference designators, any semblace of 'humour' which I might have shown otherwise, is instantly set to ZERO!

Reminder: the three terminal semiconductor devices in question shall be named Q and nothing but Q!
The static magneto-electric converter based on coupled inductors gets the T.

That's not fun at all....  BJT is useful in some circumstances, but tranny or whatever other "nickname" puts more humanity into it, more poetic...sometimes you want more poetry and humour, than cold technical terms. I would use BJT if I wanted to refer to a specific type of tranny.

Q for trannies ? Look in the schematic of this DMM, they use 'S' instead.... didn't bother me at all, it was still obvious that they refered to the trannystors 

In more modern French schematics they used 'T' to designate trannystors, I never thought one way or another about it.

As long as there is no ambiguity, the rest is a matter of taste... it's like code conventions when writing S/W.... it does not really matter what convention you follow in your company... what matters is that everybody in the company observes strictly the same convention, so that all the S/W developers can work on a same / common project seamlessly and not creating errors unknowingly.

OK, I under stand you are German and I am French, so yes I like a bit of romance and poetry in things, and sometimes I will say tranny and sometimes I will use a more technical term, depending on context and intent.

Looks like Dwagon managed to start another endless discussion... we have just, barely survived the EV subject, now it's about the right to call transisotrs trannies. Oh well.... I guess TEA needs one arguing after another to stay afloat ?! 

I am sorry to be a disappointement... but I will keep saying tranny when I feel ilke it !

So we have two main types of trannies, BJ and FE.
What is E, equal, equally?

[Ice-Tea]

Yokogawa WT1600. These things fetch a pretty high price, didn't quite understand why. I'm starting to, though... It's like the engineers asked:

"So, what does it need to measure"?
"Everything.
"Ehm, what visualisation options?
"All of them".

[Cerebus]

No such thing as "auxiliary driving lights" for road use. On the front they are headlights or foglights. Less tha 24" above the ground can only be a foglight.
On diconnectting DRLs, if you have an accident involving vibility of your vehicle this might be used against you.

One needs to be careful when making definitive statements like "Less tha (sic) 24" above the ground can only be a foglight". While that might be true under, for example, "The Road Vehicles Lighting Regulations 1989", it may not necessarily be true of New York's Vehicle and Traffic laws.

And anyway, if we are talking about "The Road Vehicles Lighting Regulations 1989" the relevant figure for the minimum height of headlamps is 500mm.

[capt bullshot]

Yokogawa WT1600. These things fetch a pretty high price, didn't quite understand why. I'm starting to, though... It's like the engineers asked:

Nice one.
6ch power analyzer with up to 1MHz BW and 0.1% accuracy (but not both specs at the same time, 0.1% power accuracy @ 1MHz is plain unrealistic). There are not many manufacturers that can get this right, Yokogawa cleary is top notch in this category. And as these are quite specialized, there's neither a lot of them on the market nor significant competition.

Want one, but I'm absolutely not willing to pay the price tag these things usually have. So don't even think of selling this thing to me

BTW.
Doing all these measurements and visualisations isn't the big deal (been there, done that in my first and second job), even less a hassle with todays DSP and MCU computing capabilities. Buy some text book and you'll find all the formulas required for the calculations. Sit down and write some C / DSP code, and make some nice screens to visualize the results. Getting the analog front ends right is some kind of an art.