Test Equipment Anonymous (TEA) group therapy thread

[bd139]

l

Naaahhh... you're not wrong. Characterizing noise is one of the areas that, IMO, a good analog scope still excels at and in many ways beats out a DSO. In this scenario, it does the averaging by dint of its inherent nature. You don't need the absolute detail that digitizing gives you; you just want to see where the fuzz is thickest and where it ends.

Amaze youngsters by using an analogue scope to quickly and easily measure the RMS value of wideband noise.

At amaze them with an HP 3400A which is even easier

Talking of which I need one of them to measure noise figure on something.

OK. Go on. Do that by the end of the week, rather than at some indefinite time in the future

Considering I don’t have any analogue oscilloscopes at the moment I shall defer until some indefinite time in the future

A clear demonstration of how unwise it is to dispose of anything.

Theres a compromise somewhere there.

Actually if I’m remembering how to do it properly it might be possible to do it with intensity grading or persistence on the Siglent. I will have to make a noise source and try it. After I’ve moved!

[mansaxel]

I think my choice of music reflects my driving

<snip>

I'm more of "go to the sources" WRT EBM, so this is the original:

https://youtu.be/M5Z0JUSrTzI

OTOH, I'm more of a jazz man:

https://youtu.be/Qu27ILI4B0c

...or:

https://youtu.be/O51U38Y3gIE

Edit: That 242 track is seriously dangerous to your driving license...

[Neomys Sapiens]

Stupid question for the gang.
If a water electro-valve spec is 24VAC, can I use VDC to control it?
If yes at what voltage DC current?

Yes I am a little embarrassed to ask....

I'm with the Capt.Bullshot here. Basic answer is NO.

Why even try such?
As for someone suggesting that it had been tried with a contactor: I've seen and smelled a control cabinet where someone 'tried' that with around 50 contactors. You could not touch them even at the top plastic around the contacts and it stank like a fire in waiting.

Probably because they used 24VDC instead of 12V and it cooked the coil? You might try it if you didn't have easy availability of 24VAC.

Also, what difference does it make to the contacts, whether you use the correct voltage or not? Only thing I can think of is the DC voltage was too low and the contact pressure was therefore low and the switched load was close enough to maximum that it caused excess arcing?

In any case, a control valve wouldn't have that issue. If the valve has a VA rating, just measure the coil DC resistance, that'll tell you the necessary DC voltage if you really want it spot on.

Nope. It was definitely 24V AC contactors fitted into a 24V DC system. I investigated that at a VW factory because a junior colleague called for aid. It was in 1991 during a complete refit of the famous Halle 54 and I was doing PLC coordination for the major electrical contractor of VW, a company named Velte Electric.  I have no idea how he missed that stench and the unnormal heat. Those contactors were never intended to fit in those cabinets. Either a really dumb subcontractor ran out of contactors or some event had the Aushilfslagerjunge act in the absence of someone knowledgeable - this part did not make it to me. I was subsequently given a list of all cabinets supplied by that subcontractor and we found one more like it, which was not yet energised.
It did nothing to the contacts, but the plastic housings of all those contactors were too hot to touch FROM THE COIL.

[bd139]

I think my choice of music reflects my driving

<snip>

I'm more of "go to the sources" WRT EBM, so this is the original:

https://youtu.be/M5Z0JUSrTzI

OTOH, I'm more of a jazz man:

https://youtu.be/Qu27ILI4B0c

...or:

https://youtu.be/O51U38Y3gIE

Edit: That 242 track is seriously dangerous to your driving license...

More of a fan of the derivative works these days if I’m honest, probably as I was a bit late to the scene 

Operating Tracks by Front 242 is a winner though

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

[mansaxel]

So I replaced that RIFA. PSU board was easy and quickly to remove from the scope. Paid extra attention to plastic rod operating the mains switch, since you said it could break easily... got lucky, it came out and back on, with no drama 

You put a Rifa cap back into the unit!?  I hope you got a late date code on that part............... 

It was new stock Kemet from Mouser. Probably as good as it gets. (Kemet bought RIFA from Evox who bought it from Ericsson who bought it from its competitors back in the late 50s when there was capacitors on the world market again.  RIFA is short for "Radioindustrins Försörjningsaktiebolag" (Radio Industries Supply Company) and was a joint venture between Ericsson, ASEA, AGA and possibly some more, to build components in Sweden during WW2. )



(Trade rag advert from the late 1950s)

[med6753]

I think my choice of music reflects my driving

<snip>

I'm more of "go to the sources" WRT EBM, so this is the original:

https://youtu.be/M5Z0JUSrTzI

OTOH, I'm more of a jazz man:

https://youtu.be/Qu27ILI4B0c

...or:

https://youtu.be/O51U38Y3gIE

Edit: That 242 track is seriously dangerous to your driving license...

If I listen to this while driving I can guarantee myself a speeding ticket. 

[tggzzz]

l

Naaahhh... you're not wrong. Characterizing noise is one of the areas that, IMO, a good analog scope still excels at and in many ways beats out a DSO. In this scenario, it does the averaging by dint of its inherent nature. You don't need the absolute detail that digitizing gives you; you just want to see where the fuzz is thickest and where it ends.

Amaze youngsters by using an analogue scope to quickly and easily measure the RMS value of wideband noise.

At amaze them with an HP 3400A which is even easier

Talking of which I need one of them to measure noise figure on something.

OK. Go on. Do that by the end of the week, rather than at some indefinite time in the future

Considering I don’t have any analogue oscilloscopes at the moment I shall defer until some indefinite time in the future

A clear demonstration of how unwise it is to dispose of anything.

Theres a compromise somewhere there.

Actually if I’m remembering how to do it properly it might be possible to do it with intensity grading or persistence on the Siglent. I will have to make a noise source and try it. After I’ve moved!

Do try it and let us know the result. Obviously a simple max/min/mean trace won't help. If you can determine the right colour or intensity, you might not need to use the second channel.

[med6753]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

Mary Had A Little Lamb? 

[BU508A]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

[bd139]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

[bd139]

l

Naaahhh... you're not wrong. Characterizing noise is one of the areas that, IMO, a good analog scope still excels at and in many ways beats out a DSO. In this scenario, it does the averaging by dint of its inherent nature. You don't need the absolute detail that digitizing gives you; you just want to see where the fuzz is thickest and where it ends.

Amaze youngsters by using an analogue scope to quickly and easily measure the RMS value of wideband noise.

At amaze them with an HP 3400A which is even easier

Talking of which I need one of them to measure noise figure on something.

OK. Go on. Do that by the end of the week, rather than at some indefinite time in the future

Considering I don’t have any analogue oscilloscopes at the moment I shall defer until some indefinite time in the future

A clear demonstration of how unwise it is to dispose of anything.

Theres a compromise somewhere there.

Actually if I’m remembering how to do it properly it might be possible to do it with intensity grading or persistence on the Siglent. I will have to make a noise source and try it. After I’ve moved!

Do try it and let us know the result. Obviously a simple max/min/mean trace won't help. If you can determine the right colour or intensity, you might not need to use the second channel.

Indeed. Experimentation time.

I need a reference power measurement to compare it against. That might neatly line up with the Bird wattmeter thread 

[BU508A]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

https://youtu.be/rRncgJhNf-k

Click on this link at your own risk!

[bd139]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

https://youtu.be/rRncgJhNf-k

Click on this link at your own risk!

Ok not that bad. That is NSFW 

[med6753]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

https://youtu.be/rRncgJhNf-k

Click on this link at your own risk!

Ok not that bad. That is NSFW 

OMG. 3 minutes of my life wasted. 

[tggzzz]

l

Naaahhh... you're not wrong. Characterizing noise is one of the areas that, IMO, a good analog scope still excels at and in many ways beats out a DSO. In this scenario, it does the averaging by dint of its inherent nature. You don't need the absolute detail that digitizing gives you; you just want to see where the fuzz is thickest and where it ends.

Amaze youngsters by using an analogue scope to quickly and easily measure the RMS value of wideband noise.

At amaze them with an HP 3400A which is even easier

Talking of which I need one of them to measure noise figure on something.

OK. Go on. Do that by the end of the week, rather than at some indefinite time in the future

Considering I don’t have any analogue oscilloscopes at the moment I shall defer until some indefinite time in the future

A clear demonstration of how unwise it is to dispose of anything.

Theres a compromise somewhere there.

Actually if I’m remembering how to do it properly it might be possible to do it with intensity grading or persistence on the Siglent. I will have to make a noise source and try it. After I’ve moved!

Do try it and let us know the result. Obviously a simple max/min/mean trace won't help. If you can determine the right colour or intensity, you might not need to use the second channel.

Indeed. Experimentation time.

I need a reference power measurement to compare it against. That might neatly line up with the Bird wattmeter thread 

As per my .sig, how about a noisy resistor, an audio amp, and a moderate quality multimeter. Plus the scope, of course.

[BU508A]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

https://youtu.be/rRncgJhNf-k

Click on this link at your own risk!

Ok not that bad. That is NSFW 

OMG. 3 minutes of my life wasted. 

Bonus points for sticking it out this long. 

[tggzzz]

My actual 2022 top most played on Apple Music is embarrassing so I won’t post it here 

All the Best compilation from Engelbert Humperdinck, Barry Manilow and Dean Martin¹?

 


¹ covered by Leo Moracchioli

Worse

https://youtu.be/rRncgJhNf-k

Click on this link at your own risk!

Warning: somebody else's moppets ahead!

[Specmaster]

*puts hand up to ear*   "WHAAAAAAAT?!?"

mnem
thump.

Just today I'm coming up my road and there is a kid on a bicycle going in my direction in the middle of the road. I slowed and figured he would hear my approach. Nope. I had to come almost to a complete stop and decided I had no choice but to lay on the horn. Only then did he turn around and realize I was there and moved over. And then I saw that the jerk had earbuds on. 

Today, within 200 yards:

Police car making a three point turn across a busy, narrow, main road while his vision is blocked both ways, including hitting the kerb while he was reversing, this is him hitting the curb



woman on a pushbike stopped inside a traffic light controlled junction to play with her mobile,




man steps out into the road in front of me, without looking, 10 yards from a zebra crossing he could have used instead,



OK, who fitted the idiot magnet to my car?

What.. I think you did that, I think that has become the most commonly used phrase by BMW, Volvo and Audi drivers at least here in the UK 

[Saskia]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

[Specmaster]

Stupid question for the gang.
If a water electro-valve spec is 24VAC, can I use VDC to control it?
If yes at what voltage DC current?

Yes I am a little embarrassed to ask....

I'm with the Capt.Bullshot here. Basic answer is NO.

Why even try such?
As for someone suggesting that it had been tried with a contactor: I've seen and smelled a control cabinet where someone 'tried' that with around 50 contactors. You could not touch them even at the top plastic around the contacts and it stank like a fire in waiting.

If it is a valve, then I'd also say NO. Relays and contactors could be made suitable if a spare N/C auxiliary contact exists on them or can be added (preferably a late break one) with a suitable resistor connected across it and in series with the coil. The reason for this is to limit the current that flows through the coil once energised as the coil will overheat without it and either burn out, or the plastic bobbin will melt and cause the magnet assembly to jam up rendering the relay/contactor inoperable. Most coils are wound for AC supplies and the impedance of the coil restricts current flow, but with DC, there is no impedance factor / back EMF being applied to the current flow and hence the need to control that aspect once the relay / contactor has closed.

[Specmaster]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

Sorry to hear that, Sister in Law has as well, today is her birthday and most of the family are planning round to see (SWMBO included  ) for a coffee with her. They all plan to sit in the garden while SiL sits inside with the patio door wide open.

[BU508A]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

Take care, both of you and get well soon!

[med6753]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

Oh crap.    Get plenty of rest and if gets worse get thee to the hospital ASAP.

Get better quick.

[ch_scr]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

Get well soon!

[DC1MC]

just did the bloody COVID test. Rats, it's positive and I feel rotten ...

Time for a couple more "boosters", they will surely help  (Big Pharma that is).

Also, get well quick and hopefully it will not leave any bad traces behind.