Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 14548658 times)

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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120025 on: May 18, 2022, 11:34:16 am »
Since I burned my fingers with the evil raspberries (I do not like them...) this time I ask before.

Are you happy with the ESP32 based boards? Is the ESP32 running stable for you? Can be used in production?´
Many thanks.

I’ve stayed away after reading horror stories. Things like crashes when you write to flash during interrupts, undocumented behaviour and the ADC sucking complete balls. However there are very few SoC at that level which have the out of box features you might need and you can actually still get the things.

Ergo I’d put the engineering hat on, write your feature requirements down, do a KT decision analysis against that and STM32 and see what comes out.

As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  :popcorn: *

* oh the power of carefully misstating positions

And then completely fail to find any stock of the STM32 model arrived at.

Actually, there are some relatively new STM32s with onboard wireless functions (if that's why the ESP32 is of interest) and they're new enough that few are actually being used in production, which means there is a little stock availability of them. However they are mostly dual core and rely on that for the wireless functionality, so there are many subtle synchronisation bugs awaiting the unwary embedded programmer who doesn't have a solid understanding of the same.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120026 on: May 18, 2022, 11:39:07 am »
*wail* <--- siren



Not exactly. More like these deadly creatures.  :P :-DD



Hmm, that redhead looks familiar...
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120027 on: May 18, 2022, 11:41:34 am »
Ok an actual TE post. Black Star Jupiter 2010 arrived. Looks in good condition, appears to actually work fine although I have nothing to check that available at the moment.

Outside:



Insides view 1:



Insides view 2:



Very standard design akin to Thurlby / TTi and it is of the same heritage.

You are having now a good camera, now you need better lighting.  ;D

No. Priority one is to get a scope.  :-DD
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120028 on: May 18, 2022, 11:42:54 am »


Hmm, that redhead looks familiar...

That redhead would look familiar to a lot of us. And she does.  :o
An old gray beard with an attitude.
 
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Offline Robert763

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120029 on: May 18, 2022, 12:00:31 pm »
On the go TE repair. Ws using the naff little Maplin H93CX 20V, 5A bench PSU for work and suddenly the ammeter is showing 5.2A with nothing connected. Voltage is OK.
quick look inside."Can you see what it is yet?" (oops he got locked up...)

That's supposed to be 1000uF 35V :o
Stuck stuffed a 100uF 63V in there and all ok.
 
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120030 on: May 18, 2022, 12:19:23 pm »
Since I burned my fingers with the evil raspberries (I do not like them...) this time I ask before.

Are you happy with the ESP32 based boards? Is the ESP32 running stable for you? Can be used in production?´
Many thanks.

I’ve stayed away after reading horror stories. Things like crashes when you write to flash during interrupts, undocumented behaviour and the ADC sucking complete balls. However there are very few SoC at that level which have the out of box features you might need and you can actually still get the things.

Ergo I’d put the engineering hat on, write your feature requirements down, do a KT decision analysis against that and STM32 and see what comes out.

As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  :popcorn: *

* oh the power of carefully misstating positions
I don't wear a belt on my seat anymore unless I'm going out to the store, a restaurant or some appointment. The rest of the time I'm either wearing shorts or it's a pants-free day.  >:D

mnem
I am not my pants. No, I am not your pants, either.

In the spirit of Volvo's gifting the design of the 3 point seatbelt to the world, because of public good it represented as a safety device, I am here publicly disclosing a novel invention for anyone to manufacture because of the benefits it offers to public safety.

The device is a safety belt worn on the body. It consists of a waist belt and two thigh belts intended to firmly hold the device to the human body or any similar arrangement that will be obvious to practitioners of the art. At the front is a crossed pair of belts that once adjusted to the wearer provide a rigid connection, one from each thigh belt to the waist belt intended to resist and control rearward forces applied to the waist and thigh belts. Adjustment mechanisms in the form of buckles or similar are provided.

At the rear there is a similar pair of crossed belts with a central loose sliding buckle intended to keep the belts mechanically connected to each other while allowing the belts to be freely tightened. A sensor mechanism is housed on the outside of this buckle. These belts have on one side a fixed connection to the waist and thigh belts and on the other side are connected to the same by pyrotechnic tensioning devices.

The rearward sensor is designed to detect any immanent collision and when it does so it fires the pyrotechnic tensioning devices. This instantly tightens the rear facing straps, compacts the buttocks, and thus prevents collisions between the buttocks and any fragile, frangible, or flaming objects in their path (e.g. cathode ray oscilloscopes).

A right to manufacture the BumbleButtBeltTM is hereby granted to any party who wishes to reduce the terrifying risks posed to the public every day by errant, poorly controlled buttocks.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline GreyWoolfe

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120031 on: May 18, 2022, 12:26:31 pm »
Hopefully it'll be good enough for a Sunday drive and hobble through a field of stinky old hams (present company excepted from that - I think  :-DD).

Thanks. I surely don't stink, I take a shower once a week whether I need it or not ...  :-DD

I do actually shower every morning except on weekend days that I know I am going to work up a sweat, then I will shower afterwards.  And I even change my clothes and underwear every day, mostly
"Heaven has been described as the place that once you get there all the dogs you ever loved run up to greet you."
 
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Offline Zucca

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120032 on: May 18, 2022, 12:40:55 pm »
Since I burned my fingers with the evil raspberries (I do not like them...) this time I ask before.

Are you happy with the ESP32 based boards? Is the ESP32 running stable for you? Can be used in production?´
Many thanks.

I’ve stayed away after reading horror stories. Things like crashes when you write to flash during interrupts, undocumented behaviour and the ADC sucking complete balls. However there are very few SoC at that level which have the out of box features you might need and you can actually still get the things.

Ergo I’d put the engineering hat on, write your feature requirements down, do a KT decision analysis against that and STM32 and see what comes out.

As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  :popcorn: *

* oh the power of carefully misstating positions

And then completely fail to find any stock of the STM32 model arrived at.

Actually, there are some relatively new STM32s with onboard wireless functions (if that's why the ESP32 is of interest) and they're new enough that few are actually being used in production, which means there is a little stock availability of them. However they are mostly dual core and rely on that for the wireless functionality, so there are many subtle synchronisation bugs awaiting the unwary embedded programmer who doesn't have a solid understanding of the same.

Many thanks to all you gang! As always it is beautiful to swim in this TEA pond.
For production I mean something that do not crash for unknown reasons and leave you with a sad monkey face.
Example for production level SW: FreeBSD, ZFS, just to understand what I am talking about.

I do not want cheap stuff, I want stuff that is reliable and don't care too much about money.

I do not want to touch thinker stuff anymore.
If I need to invest my time to learn new stuff, no problem but I do not want to be disappointed later.
Learning FreeBSD after many decades or windows was not easy but boy it was worth every single penny.

Basically I need just a µC to collect/process temperature and relative humidity and show them up in a display (touchy, why not? it will not used in a car).
Target is a dew point calculation, maybe with an air pressure sensor in the big picture.

I am in a very early design stage I just want to start with the right foot.

WIFI with async web services NICE TO HAVE, but I do not want to chose a wifi board which compromise the stability.

Learning MQTT right now, very interesting stuff, but I have no experience with it. Pondering to have a stupid (BUT REALIABLE) wifi board (looks like not ESP32) and move the horse power into the MQTT brocker/server.

Slightly off topic question, why it is so hard to find a RELIABLE SBC platform?
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120033 on: May 18, 2022, 12:45:09 pm »
...As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  :popcorn: *

* oh the power of carefully misstating positions
I don't wear a belt on my seat anymore unless I'm going out to the store, a restaurant or some appointment. The rest of the time I'm either wearing shorts or it's a pants-free day.  >:D

mnem
I am not my pants. No, I am not your pants, either.

In the spirit of Volvo's gifting the design of the 3 point seatbelt to the world, because of public good it represented as a safety device, I am here publicly disclosing a novel invention for anyone to manufacture because of the benefits it offers to public safety.

The device is a safety belt worn on the body. It consists of a waist belt and two thigh belts intended to firmly hold the device to the human body or any similar arrangement that will be obvious to practitioners of the art. At the front is a crossed pair of belts that once adjusted to the wearer provide a rigid connection, one from each thigh belt to the waist belt intended to resist and control rearward forces applied to the waist and thigh belts. Adjustment mechanisms in the form of buckles or similar are provided.

At the rear there is a similar pair of crossed belts with a central loose sliding buckle intended to keep the belts mechanically connected to each other while allowing the belts to be freely tightened. A sensor mechanism is housed on the outside of this buckle. These belts have on one side a fixed connection to the waist and thigh belts and on the other side are connected to the same by pyrotechnic tensioning devices.

The rearward sensor is designed to detect any immanent collision and when it does so it fires the pyrotechnic tensioning devices. This instantly tightens the rear facing straps, compacts the buttocks, and thus prevents collisions between the buttocks and any fragile, frangible, or flaming objects in their path (e.g. cathode ray oscilloscopes).

A right to manufacture the BumbleButtBeltTM is hereby granted to any party who wishes to reduce the terrifying risks posed to the public every day by errant, poorly controlled buttocks.


To Whom It May Concern:

The Occupational Safety and Health Administration (OSHA) has determined that the maximum safe load capacity on my butt is 2 persons at a time, unless I install handrails or safety straps.

As you have arrived 6th in line to ride my ass today, please take a number and wait your turn.

Thank You.


mnem
pssstt... I'll take 2 each BumbleButtBelt™ and accessory kit... more orders to follow once production ramps up. >:D
« Last Edit: May 18, 2022, 12:57:41 pm by mnementh »
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120034 on: May 18, 2022, 12:53:27 pm »
Mandatory seat belt use became Federal law once, in 1974. Every new passenger vehicle sold in the USA had a starter interlock to prevent you from starting the car unless the driver and front passenger buckled their seat belt. The public outcry was so loud that the interlock was removed starting in 1975. And the interlock on the 1974 cars was easy to defeat.

As far as I know every state now requires mandatory seat belt use but there is no interlock. Just the reminder light on the dash and the nanny buzzer.

Here if Flori-DUH, we have lit signs on the sides of the roads that say, click it or ticket.  They must have paid someone a crap pot of money to come up with that.
Naaahhh... that was a Federal-level public awareness program back in the day. We had them in New York, Ohio and Pennsy when I was growing up. Flori-duh under Governor Nosferatu and his mini-me clone probably just hasn't touched that infrastructure since the '80s.  :-DD

mnem
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Offline Zucca

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120035 on: May 18, 2022, 01:06:15 pm »


and problem solved in Italy.
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Can't love what you don't know. Zucca
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120036 on: May 18, 2022, 01:18:59 pm »
On The Bench This Morning: Aspire R5-471T UltraBook



I picked this Acer Aspire R5-471T-51UN Flip-Convertible ultrabook up at the Thrift over the weekend because it has similar specs to my current Lenovo Flex3 1580 with busted touchscreen and hinges, and was only $80 in new unused condition, according to a Post-it stuck on the screen.

The only flaw in the thing is that the battery won't take a charge; probably the BMS in shutdown due to not being used for 5 years.  :o

I'm going to do some exploratory surgery; if the pack isn't puffy, I'll try and jump-start the cells using the ol' Lambda LQ-532.

Of course I'll post pics of the guts... provided it doesn't try to set my ass on fire.  :-DD

mnem
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120037 on: May 18, 2022, 03:03:07 pm »
Your eyes are not deceiving you. There are 3 of them. 2 fully functional and 1 still needs some work. Ever since college 51 years ago I've wanted a Type 547. In the past year or so the TE gods have seen fit to bless me with 3 of them. I'll describe the story of each in detail.



Left, S/N 002646. This was the first one. Purchased for $75 in March 2021. It was stored in an unheated but dry shed. I do not know it's prior history. Surprisingly with all the many issues it turned out to have it does NOT suffer from the HV transformer issues so common with these scopes. Because of my medical issues last year I did not start working on it until April. And it took a full 6 months (October) to finally fix all the issues and complete the restoration. One benefit of all that work is that the final vertical amplifier was upgraded to the last build level. And since completion it has accrued many power on hours and works flawlessly. The Type 1A1 plug-in is a later S/N with FET pre-amps.

Middle, S/N 008570. This was the scope I just completed restoration this week. It was one of two scopes that came from the thrift store haul back in November 2021. It was originally owned by General Electric in Binghamton, NY. Once I did an initial cleaning it powered up and had a bright and sharp trace. But after about a half hour the HV would shutdown due to the known leaky HV transformer issue. I had the HV transformer repaired by Herr Felgendreher in Germany. I do not know what process he used but so far it is successful. The scope has accumulated many power on hours with no issues. The only outstanding issue is the scale illumination does not work. It turns out there are 2 different CRT bezels for the 500 series scopes. The “thin” bezel is for older scopes like the Type 535 or 545 which have the CRT graticule on a Plexiglas plate. The “thick” bezel is for scopes like the Type 547 which have the graticule in the screen of the CRT itself. The bezel on this scope is the thin variety. Ebay has lots of thin ones but no thick ones. I'll have to keep watch. The Type 1A1 plug-in is an early S/N with nuvistor pre-amps.

Right, S/N 010425. This is the other scope from the thrift store haul in November 2021. It was also owned by General Electric. And like it's sibling once cleaned up it powered up fine with a bright and sharp trace but also after about 20 minutes the HV shut down. I decided to remove the 5642 HV rectifier tubes and install silicon rectifiers to see if lightening the load by eliminating the filaments would help. It did not. So this HV transformer will eventually need the same repair. It is currently removed from the scope.



S/N 010425 also has a significant mechanical issue. The chassis has been tweaked and is bent. It took one hell of a shot and I'm surprised it did not damage the CRT. The covers don't fit right and a plug-in does not totally seat against the front panel. I'm not sure yet what I can do to fix it. I'm still undecided if I'm going to restore this scope or make it a parts mule. If I proceed with the restore it will also need a CRT bezel.   




And flashback. As a reminder here is what those 2 scopes looked like when I first brought them home. Full of sawdust.     





An old gray beard with an attitude.
 
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Offline mansaxel

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120038 on: May 18, 2022, 03:28:13 pm »
Very standard design akin to Thurlby / TTi and it is of the same heritage.
Feels a lot like diving in the better models of 80s -90s audio gear from companies like C-Audio, BSS or Klark-Teknik; they usually had a bit more bracing to be tour-proof, but the general look is a lot like that. Usually nothing fancy; if the 'phools only knew how many TL072 stages their "Reference" recordings have passed through they'd self-ignite.  Soundcraft usually had a discrete pair of BC550 / 560 level transistors at the input, but after that it was all opamps.

Offline nixiefreqq

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120039 on: May 18, 2022, 03:29:07 pm »


Hmm, that redhead looks familiar...

That redhead would look familiar to a lot of us. And she does.  :o

oh yes!  i went out with her too.   she could suck the fillings out of your teeth.

a registered nurse now.  am betting her patients are obedient.....and a little scared. 

free range primate
 

Offline Robert763

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120040 on: May 18, 2022, 03:30:05 pm »
Since I burned my fingers with the evil raspberries (I do not like them...) this time I ask before.

Are you happy with the ESP32 based boards? Is the ESP32 running stable for you? Can be used in production?´
Many thanks.

I’ve stayed away after reading horror stories. Things like crashes when you write to flash during interrupts, undocumented behaviour and the ADC sucking complete balls. However there are very few SoC at that level which have the out of box features you might need and you can actually still get the things.

Ergo I’d put the engineering hat on, write your feature requirements down, do a KT decision analysis against that and STM32 and see what comes out.

As for seatbelts, I only wear them on Mondays, Thursdays and occasionally Sundays  :popcorn: *

* oh the power of carefully misstating positions

And then completely fail to find any stock of the STM32 model arrived at.

Actually, there are some relatively new STM32s with onboard wireless functions (if that's why the ESP32 is of interest) and they're new enough that few are actually being used in production, which means there is a little stock availability of them. However they are mostly dual core and rely on that for the wireless functionality, so there are many subtle synchronisation bugs awaiting the unwary embedded programmer who doesn't have a solid understanding of the same.

Many thanks to all you gang! As always it is beautiful to swim in this TEA pond.
For production I mean something that do not crash for unknown reasons and leave you with a sad monkey face.
Example for production level SW: FreeBSD, ZFS, just to understand what I am talking about.

I do not want cheap stuff, I want stuff that is reliable and don't care too much about money.

I do not want to touch thinker stuff anymore.
If I need to invest my time to learn new stuff, no problem but I do not want to be disappointed later.
Learning FreeBSD after many decades or windows was not easy but boy it was worth every single penny.

Basically I need just a µC to collect/process temperature and relative humidity and show them up in a display (touchy, why not? it will not used in a car).
Target is a dew point calculation, maybe with an air pressure sensor in the big picture.

I am in a very early design stage I just want to start with the right foot.

WIFI with async web services NICE TO HAVE, but I do not want to chose a wifi board which compromise the stability.

Learning MQTT right now, very interesting stuff, but I have no experience with it. Pondering to have a stupid (BUT REALIABLE) wifi board (looks like not ESP32) and move the horse power into the MQTT brocker/server.

Slightly off topic question, why it is so hard to find a RELIABLE SBC platform?

Why do you need a dual core 32 bit processor for that? An 8 bit PIC is morethan capable.....
 :popcorn:
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120041 on: May 18, 2022, 04:15:14 pm »
On The Bench This Morning: Aspire R5-471T UltraBook   

...the only flaw in the thing is that the battery won't take a charge; probably the BMS in shutdown due to not being used for 5 years.  :o I'm going to do some exploratory surgery; if the pack isn't puffy, I'll try and jump-start the cells using the ol' Lambda LQ-532...


Yeeeaahhh... that ain't happenin'. Not LiPo as expected but rather prismatic cells, all measuring 80-100mv, and at least 2 have inverted. A new one is $19 delivered tomorrow off Bezos' online crack shop; this dead-ass little POS isn't even worth the assache I spent peeling it. :P

mnem
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Offline RoGeorge

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120042 on: May 18, 2022, 04:16:04 pm »
There is FreeBSD for Raspberry Pi.

Offline Cubdriver

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120043 on: May 18, 2022, 04:43:32 pm »
I popped the cover off of the 4800A and took a few more pictures of it.  Normal HP construction of the era - well laid out and easy to access, no surprises.

Other pics at: https://pmanning.smugmug.com/Electronics/HP-4800A-Vector-Impedance-Meter  (Crappy iPad pics, at some point I'll take better ones with the DSLR)

-Pat
Are those PCBs only tin coated or is just the lighting/camera that make them look that way?

On my 4800A the PCBs are fully gold plated as was normal for HP equipment of that era.

They're tinned - no gold on them.


Mine is a 1968 engineering rev (816 serial number prefix), and based on a quick survey of component date codes appears to be at least early 1969 for its birthdate.  It looks like the model first appeared in the 1965 catalog.  What year or engineering rev is yours?

-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 
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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120044 on: May 18, 2022, 04:51:38 pm »

What is this " Linear Technology " branded calculator sitting on top of the TE patient ?
Swag from embedded world fair some years ago

Quote
Some rebranded off the shelf (which one ?) calculator, or did LT ask Casio or TI or whoever, to make them a custom calculator with their own specs / features / looks ??

No, it's an off the shelf one with no special features. Not even one of the big brands, it says "abacus" on its back side. Rather a cheap look and feel knockoff from a Casio.



BTW: it has an "poke with a needle type" reset button on it's backside, and one needs to use that button sometimes WTF?

These are made by a company called Kinpo: https://www.kinpo.com.tw/en-US/products/consumer-electronics

The TI, Casio, basic HP, generic ones are all made using the same hardware platform and software these days. The only thing that is customised is the plastic and branding. The basic OS is pretty nice though to be honest.

BUT as you will find out they are generally garbage hardware quality. I actually had to run out yesterday and grab a replacement Casio FX991EX because the 4 and integral button stopped working on my eldest's calculator.

Interesting to see that Kinpo also make the HP 10bII+ calculator for them, I have one of those inward bound very soon  :-+
Who let Murphy in?

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Offline Zucca

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120045 on: May 18, 2022, 04:52:53 pm »
Why do you need a dual core 32 bit processor for that? An 8 bit PIC is more than capable.....
 :popcorn:

Because I want to explore new planets and in my database a reliable SBC board is missing.
Oh well, I start with a PIC and let's see how it goes. Everything is good, rock stable PIC will not disappoint me.
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Offline Zucca

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120046 on: May 18, 2022, 04:53:55 pm »
There is FreeBSD for Raspberry Pi.

IHMO is like putting chocolate on crap.
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120047 on: May 18, 2022, 04:57:23 pm »
Fridge repair

Removed that dodgy looking 47K resistor from the thermostat's butt.  As soon as I grabbed it, all the paint came right off of it !
Poor resistor was not cracked/damaged at all... the cracks were in fact just the paint peeling off ! I get the thermal cycles got the pain to crack, but it was just the paint cracking.. the resistor itself is 100% fine and measures spot on...

So the problem is indeed the thermostat itself.  Old man found a replacement in his stock at home. A generic kit that will need minor mods but should work just fine. He is packing it right now and will be shipping it first thing tomorrow  :-+

In the meantime I have to cycle the fridge/copressor on and off by hand to keep my food fresh..... old man says ratio is about a third to a fourth. So total run time per day / 24H must be 6 to 8H, something like that. So ideally turn it on 15 minutes then turn it off for 30 to 45 minutes. but that's too much work for me... I am no slave. So I guess it will be more like 1hour on and 2 or 3 hours off....
Then while I am sleeping, 8 hours... either leave it off but temperature might drop too much I don't know... so might leave it on all night...
Ideally old man told me to just power the fridge via a timer but I don't have one.   Probably costs 2 Euros on Amazon but I need a solution right now, not in 3 days (dream on) or a week, all being well with shipping of course, you have to have faith.

Or maybe I could cobble an electronic timer together quick and dirty in the lab ?! That could be a fun  project..

I have relays and TRIACs as well. I could just make  a little timer running from a battery, for convenience/quick design, and just make it drive a relay ?!  :-//

So I need a 555 I guess !!  :-DD

Do I even have one ? No idea as I have not yet got to the point of sorting IC's yet. I am still sorting discrete semi-conductors at the moment.

Worst case I guess I could just use some op-amp and make a variable duty cycle  square wave oscillator ?

Of course doing very long periods is not very convenient / reliable with RC networks.... so maybe I could instead make such an oscillator run at a faster / more convenient speed, using "manageable" values of C and R, and then feed that a logic chip, a counter/frequency divider, maybe 2 of them cascaded, so I could achieve long periods yet easy to adjust ? Then the output of the counter would drive a little transistor which would drive the relay that would turn the mains on and off for the fridge.... hmm yeah that sounds like fun, let's try to cobble that together this evening !!!  :D

My first design project in my new lab, first project in 15 years !!!  >:D

All thanks to my fridge failing ! Everyone should have a failing fridge in his life, it brings good !!!  >:D

 
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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120048 on: May 18, 2022, 05:00:09 pm »
Ok an actual TE post. Black Star Jupiter 2010 arrived. Looks in good condition, appears to actually work fine although I have nothing to check that available at the moment.

Outside:



Insides view 1:



Insides view 2:



Very standard design akin to Thurlby / TTi and it is of the same heritage.
Not 100% certain, but I think that they were the same company, just a different brand name, they certainly shared the same address so that's a pretty good clue, as did Thandar and then I think they decided it was better to run with a single brand and called themselves TTi Ltd.   :-+
Who let Murphy in?

Brymen-Fluke-HP-Thurlby-Thander-Tek-Extech-Black Star-GW-Avo-Kyoritsu-Amprobe-ITT-Robin-TTi
 

Offline Zoli

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #120049 on: May 18, 2022, 05:02:48 pm »
Fridge repair
...
In the meantime I have to cycle the fridge/copressor on and off by hand to keep my food fresh..... old man says ratio is about a third to a fourth. So total run time per day / 24H must be 6 to 8H, something like that. So ideally turn it on 15 minutes then turn it off for 30 to 45 minutes. but that's too much work for me... I am no slave. So I guess it will be more like 1hour on and 2 or 3 hours off....
...
Typical job for a microcontroller  >:D :-DD :-DD
/Ducks incoming wave of boots
 
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