Activity for Lundinâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #285878 |
All of this sounds like good ideas, I vote yes on all of your proposals. Based on the current site activity I think votes could easily be capped at 5 per day, perhaps even lower. We roughly get at most one new question per day currently. (more) |
— | almost 3 years ago |
| Comment | Post #285858 |
So it seems that this would be like Papers but lower the bar of what's expected? Maybe "Articles" would be a good name? Since that implies something that might get printed in a journal but not necessarily a full scientific study, which is what I think of when I hear "Papers". (more) |
— | almost 3 years ago |
| Comment | Post #285855 |
This kind of irregular voting in a short period of time would have set off an automatic protection mechanism on SE. I believe 3 down votes against the same user in a short amount of time would lead to moderators getting notified and a vote rollback kicking in, something like that - I don't know the d... (more) |
— | almost 3 years ago |
| Comment | Post #285817 |
Thanks for the feedback. In this case the antenna connector is the standard horrible little U.FL, which is connected with coaxial to a bigger one grounded to chassis. The main ESD risk is when someone is connecting or removing the coax. It's quite easy to touch the center pin with ones fingers on a U... (more) |
— | almost 3 years ago |
| Comment | Post #285721 |
@#53110 I have a specific problem which I thought was related to ESD. Turns out it wasn't... This question here is mostly conceptual - how would I go about placing a TVS in a RF path? (more) |
— | almost 3 years ago |
| Comment | Post #285721 |
@#52935 Yes and these tests are usually not hard to pass, in my experience, I've done lot of such tests in the past. Basically if every metal part is grounded and every input from connectors is protected, you pass. But in this specific case with an antenna (connector), I'm not sure how to add protect... (more) |
— | almost 3 years ago |
| Edit | Post #285787 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Creating a FAQ: how to read a datasheet How about this: - I create a meta thread here where everyone is welcome to post contents, feedback and proposed changes. - The question of the meta thread should contain a continuously updated draft, which everyone can leave feedback to for at least a couple of weeks. - Then I create a Paper cat... (more) |
— | almost 3 years ago |
| Comment | Post #285782 |
I've done lots of self-answered Q&A here on Codidact, but the problem with that is that then I stand as the author and none would come in and edit the actual contents of the posts. (more) |
— | almost 3 years ago |
| Edit | Post #285781 | Initial revision | — | almost 3 years ago |
| Question | — |
Creating a FAQ: how to read a datasheet After reading various low quality questions Someplace Else today, it (once again) occurred to me that a whole lot of people, mostly hobbyists and engineering students, have no clue how to do the most basic thing of all: how to read a datasheet. Specifically, what the various parts such as absolut... (more) |
— | almost 3 years ago |
| Comment | Post #285737 |
Any [human body model](https://en.wikipedia.org/wiki/Human-body_model) will do for now. (The one defined in MIL-STD-883 is for example available for free). Considering conducted susceptibility from other sources like charges to chassis might be the next step, but for now I'm just trying to narrow dow... (more) |
— | almost 3 years ago |
| Comment | Post #285725 |
They also break in different ways. Some just are dead, conducting nothing. Others only work in one direction. And this latest one seemed to have shorted tx with rx with antenna. Which perhaps implies varied strengths of a ESD. Had it been some standing wave/impedance matching/reflection problem, I'd ... (more) |
— | almost 3 years ago |
| Comment | Post #285725 |
Thanks for the feedback. It sounds as we will need to run this in a simulator or we'd be fumbling around in the dark :) In case of the tx path behind the switch, then this "pi-filter" is actually part of a larger Chebyshev filter which should be split across the switch like this according to the RF e... (more) |
— | almost 3 years ago |
| Edit | Post #285721 | Initial revision | — | almost 3 years ago |
| Question | — |
How to protect RF switches from ESD? Assume that I have some generic antenna connector, followed by a pi-filter/50ohm impedance matching components, then a DC blocking cap (as per the RF switch recommendations) and then a RF switch for split tx/rx semiduplex transceiver, as in this schematic: antenna schematic How do I best protec... (more) |
— | almost 3 years ago |
| Comment | Post #285693 |
@#52987 I answered that comment. (more) |
— | almost 3 years ago |
| Edit | Post #285698 | Initial revision | — | almost 3 years ago |
| Answer | — |
A: Are reference requests on-topic? We haven't really addressed what SE would call "requests for external resources" here. I think it's quite clear that we aren't taking shopping recommendations, as in "where do I buy this part". Asking where to find books is similar, so I'd that say such questions are off-topic. I think it would be... (more) |
— | almost 3 years ago |
| Comment | Post #285693 |
I've added some details from the AN regarding PCB layout recommendations for this part, where all of this comes from. (more) |
— | almost 3 years ago |
| Edit | Post #285687 |
Post edited: |
— | almost 3 years ago |
| Comment | Post #285687 |
@#52987 Well I suppose, though then the question turns much too broad and complex - I don't expect anyone to go read a thick datasheet plus a bunch of AN on my behalf. I've updated the question with the expected output power where this filtering would be needed. I understand this as at high output po... (more) |
— | almost 3 years ago |
| Edit | Post #285687 |
Post edited: |
— | almost 3 years ago |
| Edit | Post #285687 | Initial revision | — | almost 3 years ago |
| Question | — |
How to calculate the RC filter of a TCXO for a RFIC reference? I have a 30MHz TCXO circuit (TCXO datasheet) like this serving as local oscillator to a RFIC: TCXO filter The RFIC manufacturer recommends to "add filtering caps" for high RF output cases. That is >20dBm, after which I suppose they are concerned that the fundamental signal radiates back int... (more) |
— | almost 3 years ago |
| Edit | Post #285648 | Initial revision | — | almost 3 years ago |
| Question | — |
Standardized schematic/layout file formats for PCB CAD tools? As we know there exists numerous different kinds of PCB CAD software. The big ones seem to be Eagle, KiCAD, Altium, OrCAD, Solidworks, DesignSpark and probably a few more. When it comes to mechanical PCB file formats, there is Gerber which seems to be the universal standard. But also .dxf for mech... (more) |
— | almost 3 years ago |
| Comment | Post #285543 |
@#52987 Yeah it makes sense, though why not also compensate for inaccuracy in the local oscillator and the mixer? I just checked what the datasheet of the previous RFIC I worked with and it actually says it's located on the LNA too - the RSSI is fed as input to the AGC. So maybe AGC on the IF amplifi... (more) |
— | almost 3 years ago |
| Edit | Post #285543 | Initial revision | — | almost 3 years ago |
| Question | — |
Location of AGC in a superheterodyne RX chain RF novice here. If using a superheterodyne receiver for the purpose of FM/FSK modulated signals, I'm wondering if the location of an optional automatic gain control (AGC) circuit is always placed on the IF amplifier in such receivers, or if there are other options? I've been reading Superhet Radio... (more) |
— | almost 3 years ago |
| Edit | Post #285375 |
Post edited: |
— | almost 3 years ago |
| Suggested Edit | Post #285375 |
Suggested edit: (more) |
helpful | almost 3 years ago |
| Comment | Post #285346 |
That is, we did pretty much as in your upper left example picture. (more) |
— | almost 3 years ago |
| Comment | Post #285346 |
Reason I ask is I've been in several projects where we placed the via more or less directly adjacent to a pad. Tight designs with 144QFP and similar. I don't know if it is actually good practice though, or if some tricks were used with solder masking or stencils. Though I don't recall the PCB vendor ... (more) |
— | almost 3 years ago |
| Comment | Post #285346 |
On the actual pad or very close to it? Could you post an example picture of the proposed via layout? (more) |
— | almost 3 years ago |
| Comment | Post #285171 |
@#54107 If not on-topic here - as you can see there's no consensus - then such questions should be fine at https://software.codidact.com/. Particularly questions regarding the higher layers and the Internet protocol suite. Questions that are specific and solely about the physical and data link layers... (more) |
— | about 3 years ago |
| Comment | Post #285198 |
@#36396 Ok then I believe you merely have to design the zener barrier after zone 0 rules but you shouldn't need to worry about things like random shorts elsewhere on your PCB. I mean as long as you have a resistor and a fuse living up to the requirements of 60079-11, then it wouldn't matter if for ex... (more) |
— | about 3 years ago |
| Comment | Post #285201 |
@#36396 The general recommendations are something like this: https://www.sensorland.com/HowPics/Zener-001.gif. For higher safety levels, multiple zeners in parallel are used. So regarding my previous note about your zeners on the supply, a similar circuit should be placed towards the hazardous zone i... (more) |
— | about 3 years ago |
| Comment | Post #285198 |
@#36396 Yes temperature limits only apply inside the zones. Since you used 3 zeners I assumed it was for zone 0/20. Generally speaking - take for example a gas station: zone 0 would be inside the fuel containers, zone 1 would be the pumps, zone 2 would be the rest of the gas station, not hazardous zo... (more) |
— | about 3 years ago |
| Comment | Post #285201 |
Actually after reading chapter 7.3 I don't think the fuse is optional either. It seems that a PTC thermistor might be acceptable though. (more) |
— | about 3 years ago |
| Comment | Post #285201 |
I believe it's the other way around: a series resistor is mandatory but the fuse is optional. From IEC 60079:11 9.1 "In level of protection "ic" safety barriers, the minim requirement is a single zener diode and a current limiting resistor". Where "ic" means intrinsic safety zone 2, the lowest requir... (more) |
— | about 3 years ago |
| Edit | Post #285198 | Initial revision | — | about 3 years ago |
| Answer | — |
A: Flyback transformer with Intrinsic Safety Disclaimer: I'm not an expert of EX classification myself, but I once was project/product manager for such a project (a zone 0/20 intrinsic control system product). While I can't answer the question directly since my product contained no transformers nor flyback regulators, I can share some related e... (more) |
— | about 3 years ago |
| Comment | Post #285171 |
I disagree, since the OSI model is fundamental to any data communication. For example I often find myself in discussions where people ask how to send data over CAN bus or UART. Then I have to explain that how to send data isn't covered by CAN or UART, since they only specify physical and data link la... (more) |
— | about 3 years ago |
| Comment | Post #285155 |
I started a discussion regarding if these kind of questions should be on-topic here or not, see https://electrical.codidact.com/posts/285166. (more) |
— | about 3 years ago |
| Edit | Post #285167 | Initial revision | — | about 3 years ago |
| Answer | — |
A: How to treat data communication questions? I think these kind of abstract/big picture data communication questions should be on-topic here. Such as the mentioned question about the OSI model. I've been actively pushing for software.codidact.com not to accept embedded systems questions and refer such questions to this site instead, so that ... (more) |
— | about 3 years ago |
| Edit | Post #285166 | Initial revision | — | about 3 years ago |
| Question | — |
How to treat data communication questions? This question here about the OSI model was closed as off-topic. How should we treat questions about data communication? What is definitely on-topic here: - Embedded systems programming, including microcontrollers and FPGA. - Specific software or hardware questions about industry standard buses l... (more) |
— | about 3 years ago |
| Edit | Post #285140 | Initial revision | — | about 3 years ago |