Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Get you friend to demonstrate how, while driving along, he deals with

• the screen starts misting up: how does he redirect ventilation
• you are about to drive through smoke from a fire; how does he switch from external air to recirculating air

I can't speak to the Tesla case but the number of bells and whistles in the new (to me) BMW surprised me in this regard. If in "auto" climate mode the answer in both cases would be "nothing", there are sensors for both misting up and external air quality and the car will automatically do the right thing. There are also physical "demist the windows with the aircon" and "fresh/recirculate/auto air circulation" buttons if I have the climate control off or in manual mode. The answer for the old car would vary between "fiddle with lots of manual controls" or "stop and put the roof up/down", but it had the two great advantages over the 'new' car of (1) having a soft top, (2) having the engine just behind the driver's seat - both qualities I shall miss.

Lotus Elise?

Lotus Elise is on my list of desirable cars that I'd rock in a minute. They are very rare here but I have seen one up close and there was someone local that has (had?) one. But I understand you practically need a shoehorn to get into it. 

[TERRA Operative]

Think I'm going to go buy a Peak Atlas ZEN50 Zener diode tester tomorrow. I've needed a zener diode tester on a number of occasions now and setting up a multimeter, power supply and resistor is a pain in the bum.

Anyone got any reason why I shouldn't?

It'll increase the "margin of excuse" you'll need to buy yourself a good SMU? 

Edit: The 3A current sinking capacity of my HP 6611C power supply when using it in poor-man's SMU mode came in really handy last week. I had a 5V 2A wall wart give up the ghost and the replacement eBay special could only supply 450mA @ 5V despite being rated for 2A. A photo of the HP 6611C display proving this got me a virtually instant refund.

Well, I already got a HP 4145A and 4145B if that counts? , each with a test fixture, and one full set of adapter boards for the 4145B with a few extras for the 4145A.
I just need a set of triax cables and I have a complete set up for the 4145B, but triax cables are pricey.....

And these are just a little overkill for a quick check during troubleshooting....

I would buy another multimeter and power supply for the same money 🤣

I don't need yet another DMM and power supply! (except of course I do...  )

[Robert763]

Double diode saga follow-up.

Hmmm... I might have come across one that actually, truly behaves like I mistakenly thought that this TO3 vintage diode was doing.

I have here a more modern, TO220  STSP20xxCT made by ... well ST.

Datasheet available. It is indeed a dual diode, common cathode, low drop / Schottky.

Chinese tester confirms this but again shows a resistance between the two anodes !
Not a short this time, more like a few k-ohms, 5,000 something like that.
I confirmed this "by hand" with a DMM.

I am not dreaming this time... it is happening.

I don't understand how this is possible but it's there.

Why don't you plot V vs I for each component? That would give useful information.

Well because I have not time for that right now. I am focused on sorting all these freaking components for now ! 

So for now I have set that diode aside. Will come back to it later.

I am almost done sorting though, should be finished this evening I think.
A few components I just can't find a datasheet or any info on them, so I am not wasting my time with them, they have been discarded. Not thrown away just yet, just discarded...

When you say "by hand" are you touching the leads? It could be your body resistance.

[Peter_O]

Just caculated my car costs over the last 4 years and came up with 169 Euro/month or 51ct/km in total incl. loss in value, repairs, maintenance, tax, insurance, all liquids incl. gasoil, ... washing. It a 2016 Peugeot Tepee Partner 1.6 AdBlue HDI. OK, it's not running much due to corona.

Reason for doing the caculation is a motor error which turns out to be a bad heater plug. Unfortunately it can be screwed loose, but the end is carbonized or bend, so it cannot be pulled.
My trusted car repair people would next try to blow out the plug by compression. But in case it fails there would be the way forward only, which is to take the cylinder head off. We decided to give summer and some long distance rides the chance to burn free a maybe only carbonized plug. Hope dies last.

But even in case we need to take off the cylinders head in autumn I will stay way below the initially budgetd costs for this car.

What's the trick?: In May somebody drove a small dent into my parking car and run. But there was a witness and finally I got 4k Euros from their insurance, which helps with the 'depreciation' of the diesel a lot.

[mnementh]

Think I'm going to go buy a Peak Atlas ZEN50 Zener diode tester tomorrow. I've needed a zener diode tester on a number of occasions now and setting up a multimeter, power supply and resistor is a pain in the bum.

Anyone got any reason why I shouldn't?

The Peak/Atlas siren song. 

You buy one, you're going to hear it singing to its cousins til you buy the next one, and the next one, etc... Then those will sing at you in harmony until you have the full set.   

mnem
Then they'll sing choir to the matching fitted case until you buy or print it...

[Vince]

Double diode saga follow-up.

Hmmm... I might have come across one that actually, truly behaves like I mistakenly thought that this TO3 vintage diode was doing.

I have here a more modern, TO220  STSP20xxCT made by ... well ST.

Datasheet available. It is indeed a dual diode, common cathode, low drop / Schottky.

Chinese tester confirms this but again shows a resistance between the two anodes !
Not a short this time, more like a few k-ohms, 5,000 something like that.
I confirmed this "by hand" with a DMM.

I am not dreaming this time... it is happening.

I don't understand how this is possible but it's there.

Why don't you plot V vs I for each component? That would give useful information.

Well because I have not time for that right now. I am focused on sorting all these freaking components for now ! 

So for now I have set that diode aside. Will come back to it later.

I am almost done sorting though, should be finished this evening I think.
A few components I just can't find a datasheet or any info on them, so I am not wasting my time with them, they have been discarded. Not thrown away just yet, just discarded...

When you say "by hand" are you touching the leads? It could be your body resistance.

Nope I am careful not to touch the probes, though even if I did I would typically measure a few Meg not a few kilo-ohms... I am not that conductive !
Also, chinese tester, where the part is inserted in the ZIF socket hence me not touching it during the test, and DMM agree on that resistance.

I don't understand where that resistance comes from. I picture in my head a big die with big ass P-N-P junctions, one anode on one side connected to one pin, another pin at the other end of the die connected to the other anode.... the two are far away from each other... how could there be a leakage/path between the two ?! I don't know. But it clearly measures so...

It's a TO220 package not TO3 here, so I can't just open it up to see for myself, no chemicals here to dissolve that package. Frustrated I am, my curiosity will never be satisfied..... 

Maybe the diodes overheated, too much current, that kinda "melted" / degraded the substrate in some way and now creates weird and wonderful things...

[Vince]

Think I'm going to go buy a Peak Atlas ZEN50 Zener diode tester tomorrow. I've needed a zener diode tester on a number of occasions now and setting up a multimeter, power supply and resistor is a pain in the bum.

Anyone got any reason why I shouldn't?

I too would like a way to quickly test Zener diodes. Can't justify the money for a dedicated tester though. Instead I put my Zener need in the balance to strengthen my motivation to get a proper / modern power supply these old  HP / Agilent ones with a VFD display every one has but not me, where you can control the short circuit accurately and display the voltage accurately too.

I could just shove the Zener in the jacks of the PSU and limit the current to 1mA and see what voltage that gives me. Then increase the current and see how the voltage behaves.
Now I think of it maybe it's not a good idea : the output caps in the PSU might discharge into the Zener when I connect it, and blow it ?
But if I set the output voltage to Zero and current limit it to 1mA say, then slowly increase the voltage,  should be safe ?

Anyway, I could still put a series resistor to limit the current to a safe level. Could make a little test jib with  ZIF socket, a resistor, couple 4mm binding posts and I could just grab that whenever I need to test a Zener, grab a couple test leads to connect it to the PSU and that's it.

I think that's how I will go about it. Cheap, simple, efficient... and an excuse to buy a decent PSU.

[Cubdriver]

Get you friend to demonstrate how, while driving along, he deals with

• the screen starts misting up: how does he redirect ventilation
• you are about to drive through smoke from a fire; how does he switch from external air to recirculating air

I can't speak to the Tesla case but the number of bells and whistles in the new (to me) BMW surprised me in this regard. If in "auto" climate mode the answer in both cases would be "nothing", there are sensors for both misting up and external air quality and the car will automatically do the right thing. There are also physical "demist the windows with the aircon" and "fresh/recirculate/auto air circulation" buttons if I have the climate control off or in manual mode. The answer for the old car would vary between "fiddle with lots of manual controls" or "stop and put the roof up/down", but it had the two great advantages over the 'new' car of (1) having a soft top, (2) having the engine just behind the driver's seat - both qualities I shall miss.

Lotus Elise?

Lotus Elise is on my list of desirable cars that I'd rock in a minute. They are very rare here but I have seen one up close and there was someone local that has (had?) one. But I understand you practically need a shoehorn to get into it. 

There is NO graceful way to get in (or even more challenging) out of one.  The roof is low, the side sills are high, and the seats truly are 'bucket'.  That said, it's a street legal go-kart.

-Pat

[tggzzz]

Get you friend to demonstrate how, while driving along, he deals with

• the screen starts misting up: how does he redirect ventilation
• you are about to drive through smoke from a fire; how does he switch from external air to recirculating air

I can't speak to the Tesla case but the number of bells and whistles in the new (to me) BMW surprised me in this regard. If in "auto" climate mode the answer in both cases would be "nothing", there are sensors for both misting up and external air quality and the car will automatically do the right thing.

Oh great, even more sensors to go wrong. The one time the 19yo Toyota Yaris failed was due to a sensor.

There are also physical "demist the windows with the aircon" and "fresh/recirculate/auto air circulation" buttons if I have the climate control off or in manual mode. The answer for the old car would vary between "fiddle with lots of manual controls" or "stop and put the roof up/down", but it had the two great advantages over the 'new' car of (1) having a soft top, (2) having the engine just behind the driver's seat - both qualities I shall miss.

Physical controls are fine.

The Tesla (and other?) touchscreen / voice activated controls are a serious problem.

Just in: "Cars in driver-assist mode hit a third of cyclists, all oncoming cars in tests" https://www.theregister.com/2022/05/16/automous_car_ada_system_tests/

[Specmaster]

What is this "public transportation" you all are talking about?  In these parts it's called a private cab/uber or put on your walking shoes. 

Yeah, well I kinda guess its a throw back to the times when buses and trains were owned by the public and run for the public benefit which manifested itself in the form of very affordable fares and reasonable level of service to boot. These days, they are all owned by private companies that only see the bottom line on the balance sheet and a service either runs if it is profitable or is axed if not. So if you live out in the countryside, you may if you're lucky have a service once a day or even just once a week. So you need a car or you're stuffed.

In the area that Cerebus lives, he would have enjoyed these big double deck Routemaster buses and they used to operate all over London, all under the operating banner of London Transport. Areas around the edge of London, the countrified parts of London if you will, would have had the same buses but green, as in the photo, and they were called London Country. These days London country does not exist and London Transport is now split up up into smaller companies privately run. So if you don't have a car, you either grab a bus, taxi, Uber or you don your walking boots.

So in essence public transport does not exist, its all private transport. 

[Cerebus]

Oh great, even more sensors to go wrong. The one time the 19yo Toyota Yaris failed was due to a sensor.

Well the "misting" sensor is just some LEDs and photodiodes, if those don't outlive the capacitors in rest of the electronics I'd be very surprised. The air pollution sensor is another story, it's the kind that uses a heated sensor matrix which to me dictates a certain maximum power-on hours; thankfully it's about as accessible as possible and entirely self-contained on a plug-in connector, replacing it would be a five minute job and it has a list price of €55 so not too terrifying.

The downside of all modern cars is the sheer quantity of electronics, sensors and servo motors they rely on. There most be upwards of 20 or 30 servo motors in the BMW: engine, lights, ventilation, seats, the list is endless.

Physical controls are fine.

The Tesla (and other?) touchscreen / voice activated controls are a serious problem.

I'm against touch-screen only controls on things I use on a desktop, like 'scopes, on something potentially safety critical such as in a car or plane I think they're criminal.

[srb1954]

Added to all of that, it is also a hell of a lot more comfortable than a bleeding old bone shaker of a bus. Our buses, although fairly new, are so uncomfortable, windows that are designed not to completely shut, the doors have huge gaps all round them, springs feel as they are steel girders and the entire bus rattles, shakes and vibrates. These new buses, are nothing at all like the ones I used to work on, they were far more comfortable, despite being many years ago. I really would have expected far more now, cars have improved massivly so why not buses?

I've noted the same with London Transport's operator's stock. A bus ride used to be no penance, on the current busses it's a positively uncomfortable experience. A half hour ride on a bus and I feel like I need to visit the dentist to get my teeth reseated. Sure didn't used to be  that way. By direct comparison, in the last few years I've taken rides on busses in London and busses and trams in Dusseldorf in the same week, the latter were an order of magnitude more comfortable.

It's the same on the opposite side of the world. A typical public transport bus here has a teeth-rattling bone-jarring ride accompanied by the the constant whine of a straight-cut gear transmission.

It is my belief that many modern bus design are still based on the chassis and running gear of farm stock truck designs from the 1950s.

[factory]

Think I'm going to go buy a Peak Atlas ZEN50 Zener diode tester tomorrow. I've needed a zener diode tester on a number of occasions now and setting up a multimeter, power supply and resistor is a pain in the bum.

Anyone got any reason why I shouldn't?

I've used a portable DC insulation tester (Megger), combined with a DMM to measure the voltage, both at work & home to test Zeners. The current available is low enough to not destroy the Zener (unlike the TTI PSU, without series resistance). Even used this method, to prove that some ordinary diodes had been incorrectly fitted, in place of some 100V Zeners. 

Some Megger testers have output ranges from 50V up to 1kV, this is also useful for testing glow tube voltage references & neon number/symbol readout bulbs, which sometimes they age badly, or crack. The Megger/DMM will find out if they are knackered, i.e. require too high a voltage to glow, or don't glow at all.

The only Peak testers I have are the ESR60 (bought second hand) and the DCA75 (new, as used are barely any cheaper).

David

[factory]

It'll increase the "margin of excuse" you'll need to buy yourself a good SMU? 

Edit: The 3A current sinking capacity of my HP 6611C power supply when using it in poor-man's SMU mode came in really handy last week. I had a 5V 2A wall wart give up the ghost and the replacement eBay special could only supply 450mA @ 5V despite being rated for 2A. A photo of the HP 6611C display proving this got me a virtually instant refund.

Not sure I would ever buy any crappy wallwarts, or replacement PSUs, on eBay or similar sites, after seeing this fine quality example that BigClive examined.


Would the HP 6611C be happy with rectified mains, applied to the input terminals?

David

[Zucca]

The downside of all modern cars is the sheer quantity of electronics, sensors and servo motors they rely on. There most be upwards of 20 or 30 servo motors in the BMW: engine, lights, ventilation, seats, the list is endless.

Physical controls are fine.

The Tesla (and other?) touchscreen / voice activated controls are a serious problem.

I'm against touch-screen only controls on things I use on a desktop, like 'scopes, on something potentially safety critical such as in a car or plane I think they're criminal.

Yes because also they tend to squeeze a mess of menus of menus inside of a touch screen. An old lady has no chance anymore to operate modern cars correctly.
Normally after working the entire days on cars and futuristic touch screens, I drive home in my 1979 C10 with a big smile on my face.

And I agree on servos and µC, about 40 µC in a car and more to come in the future? Where are we going?  I even saw an ECU with 8 µC on it 

[Ice-Tea]

Are we back to cars? Yay!

Money spend on elektricity the last few months: nothing. Either charged for free at wifeys work or straight from the roof into my car.

Money spend on maintenance the last 35000km: 0€.

[Zucca]

10 Km/month or more?

[Ice-Tea]

10 Km/month or more?

Eh?

[bd139]

It'll increase the "margin of excuse" you'll need to buy yourself a good SMU? 

Edit: The 3A current sinking capacity of my HP 6611C power supply when using it in poor-man's SMU mode came in really handy last week. I had a 5V 2A wall wart give up the ghost and the replacement eBay special could only supply 450mA @ 5V despite being rated for 2A. A photo of the HP 6611C display proving this got me a virtually instant refund.

Not sure I would ever buy any crappy wallwarts, or replacement PSUs, on eBay or similar sites, after seeing this fine quality example that BigClive examined.


Would the HP 6611C be happy with rectified mains, applied to the input terminals?

David

Completely agree with this. The one that turned me was the USB-A someone got in Poundland that turned an iPhone 4 into a pile of ash without looking like it had even failed in any way. I was given it to see what was wrong with it and it was basically a short through the transformer to the USB port from the mains.

I have a very limited selection of chargers I buy now. Mostly these (I have 9!): https://www.apple.com/uk/shop/product/MHJF3B/A/20w-usb-c-power-adapter ... they charge anything up to 20W with no arguments unlike some shittier ones.

[med6753]

Added to all of that, it is also a hell of a lot more comfortable than a bleeding old bone shaker of a bus. Our buses, although fairly new, are so uncomfortable, windows that are designed not to completely shut, the doors have huge gaps all round them, springs feel as they are steel girders and the entire bus rattles, shakes and vibrates. These new buses, are nothing at all like the ones I used to work on, they were far more comfortable, despite being many years ago. I really would have expected far more now, cars have improved massivly so why not buses?

I've noted the same with London Transport's operator's stock. A bus ride used to be no penance, on the current busses it's a positively uncomfortable experience. A half hour ride on a bus and I feel like I need to visit the dentist to get my teeth reseated. Sure didn't used to be  that way. By direct comparison, in the last few years I've taken rides on busses in London and busses and trams in Dusseldorf in the same week, the latter were an order of magnitude more comfortable.

It's the same on the opposite side of the world. A typical public transport bus here has a teeth-rattling bone-jarring ride accompanied by the the constant whine of a straight-cut gear transmission.

It is my belief that many modern bus design are still based on the chassis and running gear of farm stock truck designs from the 1950s.

Gee, everyone holds the London transit system in high esteem yet poo-poo's the NYC transit system when it appears just the opposite is true. NYC buses are fully air conditioned, full automatic transmission, and ride surprisingly well over the shitty streets. The newest subway cars are fully air conditioned and insulated well enough that you can actually hold a conversation without shouting.   

[Cerebus]

It'll increase the "margin of excuse" you'll need to buy yourself a good SMU? 

Edit: The 3A current sinking capacity of my HP 6611C power supply when using it in poor-man's SMU mode came in really handy last week. I had a 5V 2A wall wart give up the ghost and the replacement eBay special could only supply 450mA @ 5V despite being rated for 2A. A photo of the HP 6611C display proving this got me a virtually instant refund.

Not sure I would ever buy any crappy wallwarts, or replacement PSUs, on eBay or similar sites, after seeing this fine quality example that BigClive examined.


Would the HP 6611C be happy with rectified mains, applied to the input terminals?

David

Probably (I'd have to check the schematic), but the beastie was first tested with the Fluke 27. The supply in question was supposedly the same make and model as the OEM one it replaced, itself a [very much] lesser Chinese brand. I thought I'd be on pretty safe ground, instead I got either a fake of a brand that one would have thought wasn't worth faking or a reject that then walked out of the back door to someone's disreputable cousin for resale.

[bd139]

Added to all of that, it is also a hell of a lot more comfortable than a bleeding old bone shaker of a bus. Our buses, although fairly new, are so uncomfortable, windows that are designed not to completely shut, the doors have huge gaps all round them, springs feel as they are steel girders and the entire bus rattles, shakes and vibrates. These new buses, are nothing at all like the ones I used to work on, they were far more comfortable, despite being many years ago. I really would have expected far more now, cars have improved massivly so why not buses?

I've noted the same with London Transport's operator's stock. A bus ride used to be no penance, on the current busses it's a positively uncomfortable experience. A half hour ride on a bus and I feel like I need to visit the dentist to get my teeth reseated. Sure didn't used to be  that way. By direct comparison, in the last few years I've taken rides on busses in London and busses and trams in Dusseldorf in the same week, the latter were an order of magnitude more comfortable.

It's the same on the opposite side of the world. A typical public transport bus here has a teeth-rattling bone-jarring ride accompanied by the the constant whine of a straight-cut gear transmission.

It is my belief that many modern bus design are still based on the chassis and running gear of farm stock truck designs from the 1950s.

Gee, everyone holds the London transit system in high esteem yet poo-poo's the NYC transit system when it appears just the opposite is true. NYC buses are fully air conditioned, full automatic transmission, and ride surprisingly well over the shitty streets. The newest subway cars are fully air conditioned and insulated well enough that you can actually hold a conversation without shouting.

No that's pretty good too.  Same level of crazy people and pools of piss as the tube 

[DH7DN]

Space Ceiling, the final frontier... These are the voyages of a TEA guy. His continuing mission, To explore his apartment and basement, to seek out new Test Equipment and new bargains money sinks. To boldly measure quantities which no (wo)man has done before."

 

[Cerebus]

Yes because also they tend to squeeze a mess of menus of menus inside of a touch screen. An old lady has no chance anymore to operate modern cars correctly.

Even if the layout was perfect, intuitive and didn't require any delving within menu levels, the delicacy and dexterity required to operate a touchscreen, and the focus necessary is a real no-no while trying to control a vehicle in a dynamic situation - dynamic both in terms of physically bouncing around and on terms of a 'dynamic environment' that requires your full attention to keep track of what's happening around you.

I've tried to use a single task touchscreen satnav on the move and determined that, for me at least, that's too difficult and dangerous a thing to be doing. To place most of a vehicle's auxiliary controls on a touchscreen seems to me to be one of the stupidest ideas ever.

And voice control? Let's put it like this, in a modern VW Golf with it you can get into a lot of trouble if you say the wrong sentence including the keyword "Volkwagen" to your passenger(s)...

[Specmaster]

Get you friend to demonstrate how, while driving along, he deals with

• the screen starts misting up: how does he redirect ventilation
• you are about to drive through smoke from a fire; how does he switch from external air to recirculating air

I can't speak to the Tesla case but the number of bells and whistles in the new (to me) BMW surprised me in this regard. If in "auto" climate mode the answer in both cases would be "nothing", there are sensors for both misting up and external air quality and the car will automatically do the right thing.

Oh great, even more sensors to go wrong. The one time the 19yo Toyota Yaris failed was due to a sensor.

There are also physical "demist the windows with the aircon" and "fresh/recirculate/auto air circulation" buttons if I have the climate control off or in manual mode. The answer for the old car would vary between "fiddle with lots of manual controls" or "stop and put the roof up/down", but it had the two great advantages over the 'new' car of (1) having a soft top, (2) having the engine just behind the driver's seat - both qualities I shall miss.

Physical controls are fine.

The Tesla (and other?) touchscreen / voice activated controls are a serious problem.

Just in: "Cars in driver-assist mode hit a third of cyclists, all oncoming cars in tests" https://www.theregister.com/2022/05/16/automous_car_ada_system_tests/

Self-driving cars should be banned, full stop.