Activity for Elleanor Lopezâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #291093 |
Fair enough, it would be interesting to know what the gradient looks like for such case. I suspect that standing near 750kV you would need to place your feet incredibly precise to not create a large enough voltage to kill you between your feet. Maybe the circuit was broken in less than a 1/4 phase an... (more) |
— | about 2 months ago |
| Edit | Post #291092 | Initial revision | — | about 2 months ago |
| Question | — |
Step voltage 750kV lines Some gentlemen decided to throw a hook with wire over 750kV lines in Belarus. They survived, however, I find in interesting to find out why. Assuming the connection to Earth was solid, there would be a large fault current and a gradient with step voltage: Imagealttext According to Mike Holt in... (more) |
— | about 2 months ago |
| Comment | Post #276138 |
I believe the only circuit I have seen where LED had no series resistance added was with a flat cell battery, which in itself has a high output impedance, and therefore the LED gets to live another day. (more) |
— | 8 months ago |
| Comment | Post #289574 |
Additionally, disassembling will void any kind of warranty. I mean, the cables are cut now, so warranty is off the table anyway. Personally I would guess it is a defective unit, I would buy exactly the same unit, hook it up to a PC the way it is intended to be used, observe if the ''spark'' is presen... (more) |
— | 8 months ago |
| Comment | Post #289577 |
In what software did you draw these schematics? (more) |
— | 8 months ago |
| Comment | Post #289348 |
@#52991 Is there some way you can edit these tags without turning the EE forum upside down? Each tag edit floats old questions to the top of the feed. (more) |
— | 9 months ago |
| Comment | Post #287197 |
@#36396 Are you planning on finishing this? (more) |
— | 9 months ago |
| Comment | Post #288784 |
I have to say something about the 'ordinary' board part. I took a guess at what the MCU he uses might be: K64P142M120SF5 for example. Port rise time can be 4ns. The majority of energy content is in frequencies up to 0.5x t_rise, therefore the frequency of concern is from the clock of 120MHz up to 500... (more) |
— | 10 months ago |
| Edit | Post #288770 |
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— | 10 months ago |
| Edit | Post #288770 |
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— | 10 months ago |
| Edit | Post #288770 | Initial revision | — | 10 months ago |
| Answer | — |
A: Ground pour on outer layers on 4-layer PCB You have mentioned a few points yourself, so I will try to comment on those points and perhaps suggest some reasons to add or not to add a ground plane. You mentioned twisting (I suppose warping) of the board. I believe there is a chance this happens if the board is not symmetrical copper wise, so... (more) |
— | 10 months ago |
| Comment | Post #288757 |
Thanks for the answer!
I am not taking a class, I am mostly busy with PCB design, but in the process I quite often find that I have a 'Why am I doing this in this particular way?'. So for example, application notes often specify to use 10uF in parallel with 1uF and to finish off 100nF. But when I ... (more) |
— | 10 months ago |
| Edit | Post #288751 |
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— | 10 months ago |
| Edit | Post #288751 |
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— | 10 months ago |
| Edit | Post #288751 | Initial revision | — | 10 months ago |
| Question | — |
How to convert dv/dt of noise into frequency for filter capacitor selection? Noise can be coupled between signal lines through parasitic capacitance formed between these signal lines, as $i = C\frac{dv}{dt}$ where C is the capacitance between the signal lines. Another way of noise coupling into signal lines is through inductive coupling, where changing magnetic fi... (more) |
— | 10 months ago |
| Comment | Post #288641 |
So by the same logic something like electrical issues and system design with Maneuvering Characteristics Augmentation System that brought down Boeing737 MAX planes also cannot be discussed because it was covered by the media? I think the answers highlight the weak points in design choices and provide... (more) |
— | 11 months ago |
| Edit | Post #288641 |
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— | 11 months ago |
| Edit | Post #288641 | Initial revision | — | 11 months ago |
| Question | — |
Titanic submarine control considerations The submarine built by OceanGate went missing on 18th June 2023. A lot of online criticism was directed towards the control hardware of the submarine - Logitech F710 controller. Imagealttext Imagealttext However, why is this the case? It has 2 dual axis potentiometers and some capacitive sensing... (more) |
— | 11 months ago |
| Edit | Post #288550 | Initial revision | — | 11 months ago |
| Question | — |
Cable voltage rating I was looking for guidelines of how to select appropriate cables for applications (I am interested in DC), I found IEC 183 standard which talks about high voltage cable selection for AC. Also, the status of the document is shown as withdrawn, so I assume it is not applicable. I found another docum... (more) |
— | 11 months ago |
| Edit | Post #288461 | Initial revision | — | 11 months ago |
| Question | — |
micro-RF connector crimping options Do micro-RF connector mating crimp connectors are ever sold separately together with a crimp tool? For example thisImagealttext I have looked through a lot of pages, and can only find PCB connectors + cable assemblies sold. Are RF connectors manufacturer specific and they do not share the crimp to... (more) |
— | 11 months ago |
| Edit | Post #286744 | Initial revision | — | almost 2 years ago |
| Answer | — |
A: Siglent1104 oscilloscope channels lagging It was a firmware issue. SDS1xx4X-E Firmware Revision History And Update Instructions The hardware delay between ADC acquisitions was not accounted for. I flashed the scope with new firmware and the delay is gone (more) |
— | almost 2 years ago |
| Comment | Post #286724 |
I work in academy and this screams homework. (more) |
— | almost 2 years ago |
| Edit | Post #286670 | Initial revision | — | almost 2 years ago |
| Question | — |
Siglent1104 oscilloscope channels lagging First I noticed that clock begins before chipselect gets pulled low on SPI. After eliminating potential sources I started to suspect the scope. I connected all 4 channels to function generator at different frequencies and observed 25ns gap between channel pairs. The probes were all the same 100Mhz st... (more) |
— | almost 2 years ago |
| Comment | Post #286538 |
@#36396 I added description on how to inspect the graph in post, and also added verbal description of the graphs in case the picture cannot be opened. It is a screenshot from a video, unfortunately I don't know how to enhance quality of that. There is also a link to the video with embedded timestamp,... (more) |
— | almost 2 years ago |
| Edit | Post #286535 |
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— | almost 2 years ago |
| Edit | Post #286535 |
Post edited: Described the axis |
— | almost 2 years ago |
| Edit | Post #286535 |
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— | almost 2 years ago |
| Edit | Post #286535 | Initial revision | — | almost 2 years ago |
| Question | — |
Unexpected impedance spike when paralleling capacitors I was watching a video from EEVBLOG about bypass capacitors, and he presented a theory that randomly connecting different values of capacitors in parallel can create unexpected impedance spikes: Image alt text To inspect the picture, right click and open in new tab, the scales are then visible. Reg... (more) |
— | almost 2 years ago |