You are right !

For fans of the streetfighter franchise it's quite easy to memorize: RI=U

@@VincentFischer Or for the Swiss: U = RI

@@markusmohr5470 I was taught I = V/R Same but different symbols

I learned V = I * R. Pretty basic.

Thank you!

Yeahh

Thank you for the nice words. We are glad to help!

Many thanks!

Sorry that I was too late!

Thank you for your nice words!

Glad you can use it!

Fantastic! I have not problems wit hCovid-19 because I live in the basement while creating videos ;-)

Thank you for sharing your experience!

Glad to read that you can use the content!

@@AndreasSpiess Is it possible to cover power measuring sensors with data logging function in future?

I do not think so because we build our loggers ourselves ;-) So the topic is probably too special for most of my viewers.

The subtitles are made by Luciana, my Translator.

Thank you for your kind words! You chose a nice place to judge about our country ;-)

Danke! Nun sollten wir nur noch ins Do-it-Yourself gehen dürfen...

@@AndreasSpiess Na zum Glück stellt die Post noch von AliExpress zu ;-P.

I asked Google what you weree searching yesterday and adapted the viceo accordingly ;-)

Happy to help! You are also one of my most loyal subscribers!

Have fun!

Thank you for sharing your experience!

Glad it was helpful!

Perfect! I hope everything is ok on your side? Covid-19 maybe has a long way to get to Lincoln, so you might be lucky ;-)

@@AndreasSpiess The neighbor across my house returned week ago from hospital, almost died, he had Covid-19! I spoke to his wife, about 5 meters away, and she did not get it or did not have any symptoms at all - like many people, who had it not knowing at all. And I hope you are staying safe also, I don't like you get it at all! Have a great Sunday!

An interesting part. An "INA219" with a hall sensor! Good choice.

Glad you enjoyed it!

Thanks for sharing your experience!

Thank you!

Just bear in mind that, just as with clamp-style multimeters and current transformers in general, you have to pass *only one* of the current-carrying wires through the loop of the sensor. So for an AC mains appliance you can pass through the sensor EITHER the line wire (aka live/phase/hot) OR the neutral wire (aka return), and most of the time that still requires modifying the cable (at least to remove the outer layer of insulation for countries/appliances that use double-insulated mains cables) or creating some kind of adapter that you can plug the appliance in to. If you were to pass a mains-powered appliance's cable as a whole through such a sensor it would read zero - or at least close to zero - as the field generated by the current flowing one way in the line wire would be cancelled out by the opposite current in the neutral wire. (There may be a small non-zero reading as a result of sensor error, any current leaking to earth external to the cable [hopefully none!], and - I'm not at all sure about this - maybe even non-unity power factor from capacitive/inductive loads, such as motors, switch-mode power supplies, etc.) And actually, all of these sensors have limited value for measuring mains AC appliances for two reasons: all they tell you is the current - and is that RMS current or the instantaneous current at the time your MCU decided to make a reading? After all, the current draw of most AC appliances goes up and down alongside the sine wave of the voltage! Without knowing the supply voltage, you can't know the power consumed, which is often what we're more interested in. Yes you can estimate the supply voltage at 100/110/115/120/220/230/240V RMS nominal (any I missed there?! 😹), but in practice that varies throughout the day, and thanks to the nightmare that is power factor, unless you know the true, not-RMS voltage (i.e. the exact point on the voltage sine wave - between ±141V [100V RMS] and ±340V [240V RMS]) at the moment the current was measured, at best you're probably only calculating apparent power, not real power; see en.wikipedia.org/wiki/Volt-ampere I've used some smart-home-style current-transformer clamp-based devices that are designed to be clipped around one of the wires leading to/from the house's electricity meter, and I found that they differed from the correct value (as measured by the electricity meter itself) by 20-30%, which I figure is mostly because they have no reference to the mains voltage, so they have to rely on an estimate of the RMS voltage and *a complete guess* at the house's overall power factor! :S

@@AndrewGillard very clear thank you for these details

You're welcome!

Good luck with your project!

You are welcome!

Glad you liked it!

6mA on 25A is impressif!

Thank you for sharing your experience. I assume they are similar to the ACS712?

Thank you!

You are right. When I made the video I did not yet recognize that the INA219 can measure current in both directions :-(

Bitte, gern geschehen!

Another viewer suggested this part, too. Very nice, but not cheap ;-)

@@AndreasSpiess true, it's not cheap, but come on as a Swiss you are used to that. 😜 But jokes aside, it is very precise and has a very low resistor value. So the voltage drop is minimal and the measurement range is huge.

I’ve used this part in a commercial 1kwh 24v battery pack. It performs very well.

Shit happens... Fortunately they do not cost a fortune...

Thank you for your nice words!

Maybe I will come back to you with the "RMS tricks" when I prepare a AC current video...

Glad you enjoyed it!

Jason Pluis adding a battery helps, but luckily you're on the right channel to find out about this sort of thing!:)

Without a battery it is probably easier to use the analog input and decide on the voltage at startup.

I did not cover mains in particular. There you get other sensors. But I have no overview.

Appreciate it!

They for sure are ok...

Glad it was helpful!

Glad you enjoyed it!

Omar Mekkawy I just checked the data sheet and it does have a sign bit. Also I'm pretty sure I hooked my leads up backward when my mAh tester project the first time and I did get negative current readings when the supply read lower than the load.

You are right. My mistake!

Andreas Spiess, I should have read more of the comments. You stay safe!

@@AndreasSpiess never mind. you are welcome.

Good luck with your project! Seems to be nice.

You are welcome!

You are right.

My pleasure!

The hand seems to have a lot of fans...

This seems to be a quite complex procedure. But you are right. It seems to work.

Glad it was helpful!

Maybe you watch my today's video ;-)

Thank you!

You are welcome!

I assume the INA219 has a built-in voltage reference. The ACS chips not.

Welcome aboard the channel!

This is the fate of the guy who stands up and does something...

@@AndreasSpiess wer viel macht , macht viele Fehler, wer wenig macht, mache wenig Fehler, wer nichts macht, macht keine Fehler und wer keine Fehler macht wird befördert.

Da hast du recht. Wahrscheinlich sitze ich deswegen immer noch im Keller ;-) Aber ich bin zufrieden.

My pleasure!

Very good application. Thanks for the feedback!

Glad you enjoyed it!

Pay attention. Maybe she wants to know what her husband is watching every sunday morning and reads the comment ;-) We all wait till the do-it-yourself shops are open again!

I also do not like to cut ground wires...

The probkem has been, typically, that you need to measure voltages that are higher than the V+ in the DUT, in case where you are measuring your 'own' current consumption, which is a probkem for most amplifiers... of course, low-side measurements make the V- a bit 'floating', but the voltages being measured are referenced to 'ground', making noise suppression easier... high-side measurements also affect the apparent V+ of the DUT. Lots of considerations to make, almost all of them introduce some compromise in the DUT performance/stability, or bandwidth, or sensitivity, or dynamic range, or... I spent a few years doing this stuff...

Which opamps please.

which part number are you using ?

@@OmarMekkawy OPA192

Glad you like them!

Glad you liked it!

You might be right. But I do not like to cut ground wires...

@@AndreasSpiess One context for using a low-side shunt is when you have panel mounted shunts a distance away from the monitor. It's safer to then have the shunt sensing leads routed to the monitor because they're nearer ground potential. Not sure if it's a matter of personal taste :)

Good to hear!

Maybe I will make a video about AC current measurement in the future.

Thank you!

Just change the resistor and do the calculations according ohms law (the right one, not mine ;-)

Glad you liked it!

Interesting concept. Thank you for sharing!

I assume this is the reason for the INA226 which has such a pin. For safety, this is for sure a good thing. One other sensor also has a comparator on board for that reason.

@@AndreasSpiess yes it's always better to remove software from detecting faults and acting on them, better at times to act then let the software know. i know you can use interrupts, but interrupts make it harder to demonstrate that the code will always work as you cant easy test your code being interrupted in every possible place. Thank for another thought provoking video.

Maybe a topic for a quickie...

Thank you!

Thank you for this info. Interesting!

As long as your wife does not intervene ;-)

You're welcome

My newer videos get Spanish subtitles (made by an Argentinean Lady). I do not speak Spanish :-(

You are welcome!

You are right, it is a good chip. Welcome on the channel, BTW.

Drill bits and fingers are not a good team, you are right!

:-) You are welcome!

Here the worst seems to be manageable. The new infections are constant. The hospitals still have lots of capacity...

:-)

You are right!

Glad you enjoyed it

You are welcome!

Bitte, gern geschehen.

That is not easy. Most concepts use fast switching shunts for that purpose. I covered this issue for smaller currents in the video I suggested.

You are right if you conect the opamp to the battery ground. And concerning having two different grounds, your argument is why I do not like to cut the ground wire.

Thank you for sharing your experience!

You are welcome!

Depends on what you want. The PAC1934 for sure is a capable chip. I assume, most of the maker projects do not need it. And not everybody wants to create a PCB just for measuring current. This is of course different in a professional application.

@@AndreasSpiess Yes, you're right. For most of the makers the AliExpress modules are probably more than enough. In my case, I am a bit reluctant to rely only on the AliExpress modules due to some bad experiences in the past (some of the AliExpress modules I ordered were using older, buggier revisions of a given chip, sometimes even faulty parts). I guess some of the old chip revisions can be bought fairly cheap by module makers in China. As a maker, I always like to experiment a bit with parts which aren't yet available as modules. This helps me differentiate a bit. PAC1934 has a QFN variant which I soldered on a PCB adapter. Then, I was able to play with the part on the breadboard.

The INA260 seems to be very good, but also expensive :-(

@@AndreasSpiess It's fine, especially considering the built-in laser trimmed resistor: A beefy (but lousy +/- 1%) 2mΩ alone does cost around 20% of the whole INA260 with it's 0.1% tolerance resistor. Not to mention that you can use it like that without additional external parts and thus a lot less design issues. Adafruit has a module with it for MSRP $9.95 which sounds very fair and maker friendly to me.

You are right with the bi-directional. I did not know it and di not read the ".." manual. But I do not like to cut ground wires. That is probably why I did not even look at this possibility.

@@AndreasSpiess I used to monitor charge and discharge so I remembered positive and negative currents. I prefer the High side measurement too. Thanks for the reply ;)

I did not cover AC in this video. Maybe I will do one in the future...

Thank you!