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The input leakage and average current from charge injection looks really good. Also the input inpedance / conductance looks really good: some 2-3 pA of change in the input current when going from -10 V to 10 V would be an input resistance in the 10 Tohm range and this is even with 1 PLC mode. It is cool to have some kind of self test for the input leakage.


For the sum test it would also be good  to include a 4 th measurement (BB) for the offsets. The BB rading would be subtraced from the result.  This way one has the low side at A and B twice each and the high side at B and C twice each and int the resut each point once positive and once negative. This should give a quite good compensation of offsets (e.g. from the protection part).

For the sum of 2 voltages one needs the test voltages to be floating to have the ability to connect the center point to the low side (GND) for 2 of the readings. This makes is tricky to use the same reference nad DAC. One would need some charge pump floating capacitor system (like the 10 µF film caps) or similar system with current source and series of resistors. One than still has the problem that the error can be from the ADC or the charge-pump (or current source output resistance). With the capacitor the issues are leakage, switch charge injection and also parasitic capacitance that can pump out some charge.

The result from the sum test still show quite some scattering. Part of this may be from drift in the battery voltages. At least I see this as a weak point with batteries. The dift can give a systematic error and just simple averaging is not enough. One can compensate at least for the linear drift part, by interpolation to the same time from more readings in a row.
 
Depending of the voltage reference used (especially a LM399) there can also be an error from popcorn type jumps in the reference voltage. Here just averaging over enough reading could help.

With the scattering and possible error from drift of the battery voltages it is hard to say what the results mean.
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Test Equipment / Re: SDS800X HD Bugs/Wanted Features
« Last post by Martin72 on Today at 09:42:37 am »
At the moment the term "bug" is being used in an almost inflationary way, I would be careful with such terms until it is clear that it can actually be called that.
Here in the forum and even more so "out there" (YouTube).
It gives a false impression of the device.
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Microcontrollers / Re: Is ST Cube IDE a piece of buggy crap?
« Last post by westfw on Today at 09:39:16 am »
Quote
with ARM GCC it [pre-main code]  only sets up a stack frame
Really?  What about, zeroing bss and copying initialized data from flash to ram?
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Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's
« Last post by Anthocyanina on Today at 09:37:53 am »
could anyone who owns this scope play this song through it?



i would like to see how it looks on a proper 12 bit oscilloscope

i recorded the song as seen on the AD2



thank you!
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Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's
« Last post by 2N3055 on Today at 09:35:24 am »
Can the confirmation for Auto Setup be turned off (disabled)?

My old HP scope does not do this.

It really does hold me up having to go back and press Continue.

At present, you can execute it by pressing the "Auto Setup" physical button twice.
The Wanted Features list have added whether a second confirmation is required.

Removing confirmations on functions that reconfigure many settings on a scope you just took 10 minutes to setup is bad idea in my opinion.

"This operation will format your drive C:. Do you want to continue?" Definitely good to have confirmation sometimes.  Auto and Default button should have confirmation, if you ask me...


So using a compromise solution and adding a menu setting, if the user sets it without confirmation, it is the customer's responsibility.
It is recommended that everyone get used to the current solution. Pressing the physical buttons twice doesn't make much difference.

Yes I agree that making it user configurable option is good solution, as long as factory default is to ask for confirmation..
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I have no clue on what they do and when they do it. Lately I noticed that after placing a bunch of orders some directly got marked "picked up by courier" while others are marked "to ship". (I use Dutch on Ali and the texts are "opgehaald door koerier" and "verzenden") When it is actually shipped it states "awaiting delivery". ("in afwachting van levering")

On the orders I'm still waiting for, one of them had the "picked up by courier" for maybe 9 of the 13 days delivery and was delivered to my mailbox on day 12. The others got "awaiting delivery" maybe on day 2 or 3 and the first two got here on day 8 or so. The last four have in their tracking that they arrived in the local sorting office on March the 13th, and should have been delivered by March the 18th. It is now the 28th.  :palm:

The orders I made before that set, did arrive in one package and on time, except for one item, that was delivered late in a separate package.

Why, only employees of Aliexpress might know.  :-//
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Test Equipment / Re: Siglent SDS800X HD 12 bit DSO's
« Last post by electronics hobbyist on Today at 09:31:59 am »
Can the confirmation for Auto Setup be turned off (disabled)?

My old HP scope does not do this.

It really does hold me up having to go back and press Continue.

At present, you can execute it by pressing the "Auto Setup" physical button twice.
The Wanted Features list have added whether a second confirmation is required.

Removing confirmations on functions that reconfigure many settings on a scope you just took 10 minutes to setup is bad idea in my opinion.

"This operation will format your drive C:. Do you want to continue?" Definitely good to have confirmation sometimes.  Auto and Default button should have confirmation, if you ask me...


So using a compromise solution and adding a menu setting, if the user sets it without confirmation, it is the customer's responsibility.Factory default requires confirmation.
It is recommended that everyone get used to the current solution. Pressing the physical buttons twice doesn't make much difference.
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Computers / Re: phone rom
« Last post by thephil on Today at 09:27:40 am »
Peace everyone.  ;-)

I know way too little about law to comment on the question of legality in various regions of the globe, so I won't.

Do I find it ethically acceptable to download a ROM image to restore your own phone? Yes I do. Is that legal ? I don't know. Will I point someone to a possible source if he asks nicely? Yes.
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Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread
« Last post by Peter_O on Today at 09:19:44 am »
Another HP PSU.  A 500 W HP6652A has followed me home this time.  Just need to get it converted to frontpanel binding posts.

Just need to see if Jared is willing to ship another pushbutton of Akihabara fame over to me  :-DD
I found my ..53 quite crammed inside and decided for an external solution.

2087471-0    2087477-1
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General Technical Chat / Re: Custom "R-core" transformers on ebay
« Last post by jonpaul on Today at 09:17:42 am »
Well, easy to buy lams and DIY any mains trsf.

Many off the shelf EI/EE trsf and lams  readily avail.

For valve (tube) audio aficionados a junked old CTR TV, scope, hifi will have a perfectly fine trsf for filament, B+.

J
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