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Anyway, the ground of the 350VDC supply would be the same ground as the 12V battery
No. That should not be the case. The 350V should be from an isolated DC-DC converter stage.

*op identity notice*
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General Technical Chat / Re: LTSpice: Low CPU utilization?
« Last post by iMo on Today at 10:18:00 am »
..but I can just say that they have improved parallelism a lot in LTSpice 24, so if your son hasn't updated yet, he definitely should. That'll make a big difference. Still never hits 100% CPU use, but it certainly does better than the previous major version..

From my observation they mostly improved the convergence of the solver and perhaps the intrinsic models in the 24. Some of my sims here run just fine in the 24 and the exact sources when opened in the XVII struggle heavily to show any results at all..
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If you want something 'less destructible' when it comes to input surges etc. why not go for an LM2940-5.0? It has an automotive spec input - 60V input surge and reverse polarity protection. You can even put it in backwards without damage. It's an LDO too.
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Programming / Re: Python becomes the most popular language
« Last post by Nominal Animal on Today at 10:15:23 am »
Services and command-line programs can trivially be run using only specific libraries provided with the binary, ignoring everything already on the system.  The simplest way to do this is to compile your program statically against a standard C library that does not rely on dynamically loaded modules (for e.g. resolver).

The problems arise when you wish the independent binary to interface with different services, like desktop environments and audio libraries.
Docker provides these interfaces in a standardized format.  It also uses Linux kernel features like cgroups to isolate what such processes can see of the host system.  "Container" is a very accurate description for this.

The intermediate model I've described, with symlinks to either system or application-provided dynamic libraries in an user-controlled directory, is not "containerized" at all.  It is just a way to control library versioning and dependencies in a straightforward manner in Linux.
The most common term for this is shims.

Python virtual environments (pyenv, Python venv) consist of environment variables and a shim directory for related executables inserted in PATH before standard command directories, so that for affected commands, the symlinks (or wrapper scripts) are used instead of the executables in standard directories.

Virtual machines are simply "containers" at the kernel level, limiting what hardware a kernel can access and when.

The most useful feature for myself for desktop virtual machines is snapshotting: creating a point in time, containing everything in the virtual machine at that point, that I can return to and continue as if forking a new timeline from that point.  An excellent example is creating a snapshot before installing a new application.  If I decide it was a wrong move, or it caused problems, I can simply erase that timeline completely by returning to the earlier snapshot.
When one creates installable software packages, having such a VM snapshot of the base install for testing makes it trivial to check if you have your package dependencies right.  If they are, the dependencies will drag in any missing libraries and services required, and everything will work.
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Quote
Many GD transformers have 5-10 pF CM capacitance or more, sometimes much more. This would give ~3 A (!) of CM current from secondary to primary.
Thanks for bringing this up. I know what you mean.
But if i put in values of
Stray C (interwinding) =10pF
dV = 400V
dt = 20ns

...then it gives i = C.dv/dt = 0.2A.

I wasnt sure where the 3A figure came from?
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Programming / Re: Teaching coding to a 12 year old
« Last post by bitwelder on Today at 10:11:49 am »
Before going into the choice of which platform, programming language, etc. I would rather first introduce in general to the 12 y.o. what coding is and does and then try to find some problem that s/he would be interested in solving with the programming.
If there is a practical motivation to solve a problem or to create something specific, it will be easier to tackle the techical aspects of the programming.
Based on the answers then one can think if it's more suitable start with an Arduino environment, or developing something on a computer, etc.
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The nuclear industry it trying hard to get back governmental support, as this is there life-line.  From the economic side nuclear makes no more sense. It is just to expensive and to slow to build, if one looks beyond the marketing promisses. We need to replace fossile energies fast, not in 30 or 50 years. So it does not help to start developing new reactors. They would be available in quantety just to late and it is by no means clear they could deliver on the promisses. The money would be better spend on builing the currently available renewable alternatives. They had there chance, but failed with lots of tax money spend.

It can be Ok to keep the limited number of existing reactor running, as long as they are safe. So I consider the stop of nuclear in Germany a mistake, but starting new nuclear, especially at large scale in other place would be another even larger mistake.

The new nuclear plans are full of BS promisses. A few of the nasty points to consider:
The Uranium supply is too limited to run conventional reactors one a large scale with once through fuel or just partial reprocessing as in France and the UK. The supply may be OK for the current level, but not much more to make a real difference for the climate.

The U - PU breading cycle with fast reactors  could have enough fuel, but is still not fully developed and reprocessing is dirty business and very expensive. So it is far from ready and economic. Safety of the fast reactors is also a bit more tricky. Reprocessing also comes with nuclear proliferation risks. There is also still the waste problem - less concentrated, but more volume and still bad enough to be a problem.

Thorium fuel needs even more reprocessing than the U-PU fast breaders. This is especially the case if the thorium is also recyced (which is really hard and currently set aside as it is way to expensive).
Most of the claims about thorium based reactors are big BS - maybe kind of correct if one takes one claim at a time. In the usual way of safe , cheap, clean,  available  - choose 2.
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Beginners / Re: Transistorized DC amplifier
« Last post by Picuino on Today at 10:10:17 am »
It is convenient to reduce R1 and R2 to 300 and 100 Ohms so that the transistor Q3 starts to conduct when there is little output voltage.
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Beginners / Re: Powering a LED strip reliably
« Last post by jonpaul on Today at 10:08:42 am »
Finished fixtures LEDs refl, driver avail $20..200

We use TCI Italy SLIP drivers, 0-10V dimming 100-240C mains seoectable current 100 mA ...500 mA etc.

j
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Microcontrollers / Re: CH32V003 Flash like Eprom
« Last post by brucehoult on Today at 10:04:52 am »
Strange, I recall another thread where someone was complaining that the remainder of the flash was NOT erased when a new program was written, allowing malicious users to extract the code from commercial products by uploading a very short new program that dumps the contents of the rest of the flash. (And, given two devices, you can load that program at different addresses on each one, thus extracting everything)
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