Recent Posts

1

Microcontrollers / Re: Spurious pin-change interrupts with AVR DB

« Last post by rubidium on Today at 04:15:20 pm »

Another thought I had is to invert the interrupt logic. Eliminate the internal pull-up on the pin and have the interrupt serviced on the rising edge. Perhaps a 10K to ground endures that the pin remains at logic low when an external 5V is not applied to legitimately request the interrupt.

I also take your point of having a ferrite bead at the output of the regulator. I have 22uF there now, but maybe more would help.

2

Test Equipment / Re: Power supply for home lab - do I really need a R&S?

« Last post by pdenisowski on Today at 04:11:33 pm »

You can read some older threads

Old indeed   Most of the information in those threads is from 2017 or 2020 and refers to the older version, which has been discontinued.  The current HW is the NGE100B

Old:  https://www.rohde-schwarz.com/us/products/test-and-measurement/dc-power-supplies/rs-nge100-power-supply-series_63493-387267.html
New: https://www.rohde-schwarz.com/us/products/test-and-measurement/dc-power-supplies/rs-nge100b-power-supply-series_63493-576967.html

3

Beginners / Re: Transformer - Mains Oscilloscope Probing

« Last post by Silenos on Today at 04:08:34 pm »

and in TN-CS because the Neutral and Ground cables are common at the transformer and also at each household; all the leakage current from one house flows throught the earth where is common for all houses and there is a possibility (it depends from earth composition) some part of this leakage current go through the neutral wire of a neighboring house and will trigger the RCD (the difference current between the Line and Neutral must be higher than the limit of 30mA so to triggered the RCD) besides this house don't have a leakage itself.

Did you see it? Have you caused it? Sounds highly unlikely as current just doesn't like to flow through earth, when it has the metallic return path to the transformer (N or PEN cable). If not, it will flow to the closest earthing and return to the metal, likely within the same site or the distribution grid earthing. Good household earthing has like few ohms of "static resistance", and the strickest are transformer stations earthing coming down to iirc fraction of the ohm. Also, in the TN-C/S systems the last common point of PEN->PE and N is supposed to be before RCD, so there is no way to inject residual current after the RCD through the earth.

And I am not ironic or whatever, still don't understand what are you going to do. The figs 5,6,7,8, will likely fail, as I mentioned before.
If you measure the voltage of secondary side of the transformer with nominal 24 V, and unloaded, you are very likely to get the voltage significantly higher than 24 V, and the measurement method does not matter.

Not a strange assumption if your old enough to  remember   voltage operated  devices

Elaborate, please?

4

Projects, Designs, and Technical Stuff / Component identification

« Last post by gaminn on Today at 04:06:09 pm »

Hi,
any idea what is this?



The circuit is a low power switching power supply. The controller of the switching power supply is a hybrid IC (under the black heatsink).

5

General Technical Chat / Re: Silicone vs. PVC measuring leads

« Last post by tooki on Today at 04:04:06 pm »

Yeah, looks like RG316. But I’d argue those fall squarely into the “not everyday probes” I explicitly qualified in that reply.

6

General Technical Chat / Re: Silicone vs. PVC measuring leads

« Last post by bdunham7 on Today at 03:58:26 pm »

Nobody sells multimeter test leads with PTFE (Teflon) insulation because Teflon is way too stiff.

Well, actually these are teflon-core coax.  But yeah, they're stiff.

https://www.fluke.com/en-us/product/accessories/test-leads/tl2x4w-ptii

7

Projects, Designs, and Technical Stuff / Re: Digital weigh balance - DIY

« Last post by AnalogTodd on Today at 03:57:43 pm »

Fermentation vessels can be far worse.  Yeast actually accelerate under pressure.  So if you pitch yeast into sugar and seal it.  It almost certainly WILL explode violently.  This occurs far more often than you would think.  Just with bottles and priming sugar.  Either too much priming sugar or not letting the primary fermentation complete and it can produce enough pressure to shatter glass bottles if they capped tight enough.

Yeah, I had a fermentation go a bit wild one time in a glass carboy where I had the airlock working fine when I started the ferment but it bubbled enough to push material up that blocked the holes in the airlock. Fortunately, it was in the garage so at six a.m. the next day when the carboy reached its breaking point nobody was near it.

There were still shards of glass lodged in that ceiling when I sold that house years later.

8

Buy/Sell/Wanted / Re: SALE (AU/NZ): Multicomp Pro MP710086 (Owon P4305 rebadge) at element14

« Last post by Muttley Snickers on Today at 03:56:05 pm »

I was hesitant to grab that Tenma AWG which I knew was just a Unitrend UTG2025A, but figured it was $400 cheaper than the Siglent SDG1032X I was prepared to buy so worth having a play at that price.

9

Projects, Designs, and Technical Stuff / Re: Homebrew Lock-In Amplifier

« Last post by Picuino on Today at 03:56:02 pm »

Attached:
Signal in instrumentation amplifier output measuring a capacitor of 1000uF.

10

General Technical Chat / Re: Does anyone make good SSDs any more?

« Last post by coppice on Today at 03:54:48 pm »

M3CR046 never got published to their site, but it's easily downloaded and can be applied with hdparm. For older versions you can simply extract the firmware image and their own tool (which will do exactly the same thing as hdparm) from their bootable image.

They also offer both GUI and CLI Linux versions of the 'storage executive', which I've never felt the need to play with - but is the tool run by their own update images: https://www.micron.com/sales-support/downloads/software-drivers/storage-executive-software

Is there some key problem that is only fixed in M3CR046? I've never used an update that didn't come from Crucial's site, and I've never had a problem with the drives.