Recent Posts

1

Test Equipment / Re: Second bench PSU, am I thinking about this correctly?

« Last post by KrudyZ on Today at 05:25:42 pm »

If you have the space you could pick up something like an Agilent 6624A for very little money on ebay.
This particular unit has four isolated channels and they were used in automated test equipment setups.
They do not have banana plug sockets and the UI isn't great (LCD is hard to read) as they were meant to go into test rigs or system use and were usually remote controlled.
They are of high build quality, but are obsolete, so many installations have taken them out of service once Agilent (Keysight) stopped servicing them. All of this makes them a great deal.
If you don't feel like having to repair it from the get go, you should probably not get the absolute cheapest. Look for good vendor ratings.

2

Projects, Designs, and Technical Stuff / Re: Corrosion on DIP pins

« Last post by tooki on Today at 05:25:12 pm »

I wouldn't be surprised if the caps had leaked, and the electrolyte is the reason for the rust.

3

Beginners / Re: Convert US standard 115V to International 230V

« Last post by tooki on Today at 05:23:13 pm »

but AGAIN you missed the fact that OP clarified before your first reply that the 20A input was NOT the actual maximum input current established by some empirical means, but a mystery number from a long-gone employee.

Yes, when I posted my first message in this topic, I didn't notice that he don't have other power supplies and 20A is a mystery number.
And what? This is the reason you're attacking me? 

Not attacking. Explaining our frustration.

4

Projects, Designs, and Technical Stuff / Re: Is this circuit adequate to interface a uC with a dc motor using an optocoupler?

« Last post by FBMinis on Today at 05:22:58 pm »

I re-drew the schematic, hope it's clearer.

the water dispenser is comprised of an 18650 cell, circuit board and motor. The circuit board has a uC that handles USB charging and that enables/disables the motor when its button is pressed.

I want to enable/disable the motor periodically with an ESP32C3 through an optocoupler.

5

Projects, Designs, and Technical Stuff / Re: Corrosion on DIP pins

« Last post by Haenk on Today at 05:12:12 pm »

I would rather guess these have been reworked/replaced (maybe even in factory) with a different type of solder and flux has not been cleaned, most types of flux will corrode things over time.
You might want to check the caps as well, they don't seem to have leaked, but 50 years are 50 years - therefor they might have dried out.

6

Projects, Designs, and Technical Stuff / Re: DIY Digital Caliper

« Last post by MitkoDyakov on Today at 05:11:36 pm »

here there are

https://github.com/MitkoDyakov/BluePillCaliper/tree/main/Hardware/Footprints%20-%20KICAD/CaliperPCB
https://github.com/MitkoDyakov/BluePillCaliper/tree/main/Hardware/Footprints%20-%20KICAD/CaliperBlade

7

Projects, Designs, and Technical Stuff / Re: Corrosion on DIP pins

« Last post by inse on Today at 05:11:07 pm »

Not sure whether it is rust or flux residue.
Why not brush the entire PCB with a stiff paintbrush and PCB cleaner?
If you are afraid of corrosion, you could apply conformal coating after completely overhauling the PCB.

8

Programming / Re: Linux Dependency Black Hole

« Last post by Siwastaja on Today at 05:06:27 pm »

Because their QA team tested it with this version of Python. And their support teams are ready to assist with this version of Python.

Yes. Using Python in the first place is usually a mistake, although no one got fired by using Python, so I guess it's used because it's popular. The problem with Python that fanboys fail to accept but which in actual reality hits nearly every project is that each version of Python breaks compatibility both backwards and forwards (you might not always notice if the project is very simple and thus not using many of the features, but something breaks every freaking time). It's not just Python2 vs. Python3, but really a moving target. You either target one exact Python version and require user to have that exact version, or you maintain your code all day long to match the newest version, and require user to keep updating their Python to the newest release as well. Or you use something as horrible as docker to distribute your software plus the correct Python version.

PSA to all who want to develop software:
 * Do not use bullcrap like Python or docker
 * Avoid dynamic linking, link statically if possible, and therefore:
 * Avoid library dependencies like plague;
 * Only use libraries to do very complex things, like OpenGL for 3D graphics

The danger of "just using a library" to do something as simple as formatting and sending a certain packet was demonstrated on the xz backdoor disaster.

9

Projects, Designs, and Technical Stuff / Re: Nichicon UPJ for switching power supplies - what's so special about these caps?

« Last post by wraper on Today at 05:05:18 pm »

Here is the UFG series tagline: "Rich sound in the bass register and clearer high end, most suited for AV equipment."

The best part in these is to write some vague fluff yet provide zero measurable specification difference compared to "usual" capacitors.

10

Test Equipment / Re: UTG932 testing by multiple instruments with a lot of screenshots

« Last post by bb1 on Today at 05:03:35 pm »

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