Activity for Nick Alexeev
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #291311 |
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— | 7 days ago |
| Edit | Post #291311 |
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— | 7 days ago |
| Comment | Post #291238 |
Component ID question questions have to meet certain guidelines. Here’s our [present version of the guideline](https://electrical.codidact.com/help/compid). EE.Codidact isn’t inundated by identification and repair questions, and that’s not a bad thing. After some number of such questions accumulat... (more) |
— | 20 days ago |
| Edit | Post #291238 |
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— | 20 days ago |
| Comment | Post #291238 |
@#53279 Check the output of the unidentified 331 chip on the undamaged unit. Probe the voltage at the middle pin, and at the other tantalum capacitor (the East-West one). It may be a boost switcher. That would explain two things: the connection of the inductor, the diode between pins 2 and 3. If... (more) |
— | 22 days ago |
| Comment | Post #291240 |
Yes, that’s a SOT-89. I looked up switch mode regulators [with integrated MOSFET] on DigiKey, and there are none in SOT-89. Maybe it’s a linear regulator, or a transistor. (more) |
— | 23 days ago |
| Comment | Post #291238 |
@#53279 There are two throughole pads south of these parts in this photo. They are marked [-] and [+] in copper. It looks like wires are soldered there. What's the purpose of these terminals? What's connected to them? (more) |
— | 23 days ago |
| Comment | Post #290863 |
Fixing these problems may reverse my downvote. (more) |
— | 2 months ago |
| Comment | Post #290863 |
Second problem. Your question has to be self-contained. You are referencing another article, and it's lengthy [as much as I like reading Olin's material]. Add a summary, or quote the parts pertinent to your question. Besides, the referenced resource is on another forum. (more) |
— | 2 months ago |
| Comment | Post #290863 |
First problem schematic is missing. Purpose of the circuit or principles of the operation could have compensated somewhat for the lack of schematic, but those are missing too. (more) |
— | 2 months ago |
| Comment | Post #290774 |
Monica, your initial hunch that this is a Power User question was right. This is a troubleshooting question in the deep end of Power User. I didn’t bring it up sooner because we're running low on questions at EE.codidact. (more) |
— | 2 months ago |
| Comment | Post #290774 |
What’s the model of your UPS? If it has a diagnostic output (USB, or serial), then maybe we can glean what it’s thinking. (more) |
— | 2 months ago |
| Comment | Post #290774 |
Like Olin wrote in his answer, I wouldn’t expect the 5 year old battery in a UPS to be bad, assuming that the UPS runs on battery rarely. But if there was a mains outage every few weeks (or a faulty UPS thought that there was one) for 5 years, then the battery may have worn out. Deep cycle lead-aci... (more) |
— | 2 months ago |
| Edit | Post #290602 | Initial revision | — | 3 months ago |
| Answer | — |
A: Level shifting of a 3 state logic pin Another solution which uses an ADC to read the three-state pin on the battery charger IC. The original question mentions GPIO, and doesn’t mention ADC. Maybe this will be useful for some other design which has an ADC. diagram for a level shifter between MCP73831 and a microcontroller with an ADC... (more) |
— | 3 months ago |
| Comment | Post #290601 |
@#53832 The contact resistance will dwarf the bulk resistance of the pogo pin. Why are you concerned about the pogo pin resistance in the first place? What are you going to use the pogo pin for? (more) |
— | 3 months ago |
| Comment | Post #288954 |
Did DuckDuckGo approve it? I tried the `!codd` bang DuckDuckGo, but no bangs came up. There's always `site:electrical.codidact.com`, of course. (more) |
— | 3 months ago |
| Comment | Post #290541 |
@#36396 About availability. I needed an ADuM2250 in 2022. They were out of stock in regular channels for a regular price around 10 USD, and scalpers were asking 200 USD per chip. They are available on regular distributors at the time of writing. (Other IC manufacturers have pin-compatible parts ... (more) |
— | 4 months ago |
| Comment | Post #290541 |
@#36396 A convenient thing about Analog’s magnetic isolators is that some of them are tailored to standard digital buses. [These ones](https://www.analog.com/en/parametricsearch/11034#/) have a CAN transceiver and an isolator in the same package. CANH and CANL on one side, unidirectional TXD and RX... (more) |
— | 4 months ago |
| Comment | Post #290357 |
@#53469 Could you describe your entire system please, and the application? Where does the input come from? Where does the output go to? What are you trying to accomplish ultimately? (more) |
— | 5 months ago |
| Edit | Post #290354 |
Post edited: beautification |
— | 5 months ago |
| Edit | Post #290334 |
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— | 5 months ago |
| Edit | Post #290334 |
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| Edit | Post #290334 |
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| Edit | Post #290334 |
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— | 5 months ago |
| Edit | Post #290334 | Initial revision | — | 5 months ago |
| Answer | — |
A: Noise from oscillator on top layer to clock on bottom layer with VCC & GND layers between What you are proposing may be okay (depending on other specifics of the design), but your proposed 4-layer PCB stack-up looks like a compromise. Clock is a high speed signal, and so is SPI depending on the edge raise time. Clock and SPI are on different layers: top and bottom. What acts as referen... (more) |
— | 5 months ago |
| Edit | Post #290325 |
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| Edit | Post #290325 |
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| Edit | Post #290325 |
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| Edit | Post #290325 |
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— | 5 months ago |
| Edit | Post #290325 | Initial revision | — | 5 months ago |
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A: What fabrication process is being used for jellybean parts [I used to work at Microchip.] > Is it [node size] at all important [for power management ICs] ? For power conversion ICs cutting edge MOSFETs on the scale of 5nm aren't important, because power MOSFETs are large. Larger scale MOSFETs (older generation processes) are cheaper than the cutting ... (more) |
— | 5 months ago |
| Comment | Post #290324 |
*Jellybean* means industry standard design, multiple suppliers, typically low cost in its class. LTC7880 definitely isn't jellybean, TPS610333 probably isn't jellybean. (more) |
— | 5 months ago |
| Comment | Post #290284 |
Could the extended settling time be caused by the voltage coefficient in the ceramic capacitor? I'm guessing that your capacitor is X7R or some other Class 2 ceramic, because of its value in the uF range. Try a capacitor with the same Class 2 ceramic, but with a higher voltage rating, and see if th... (more) |
— | 5 months ago |
| Edit | Post #290231 | Question closed | — | 5 months ago |
| Edit | Post #290231 | Post undeleted | — | 5 months ago |
| Edit | Post #290231 | Post deleted | — | 5 months ago |
| Comment | Post #289856 |
My favorite writings about Lithium cell safety:
[Safety Concerns with Li-ion](http://batteryuniversity.com/learn/article/safety_concerns_with_li_ion), [Lithium Battery Failures](http://www.mpoweruk.com/lithium_failures.htm) . (more) |
— | 7 months ago |
| Comment | Post #289836 |
Which CAD package do you have in mind? I suspect that the best practices vary from one CAD package to another. In particular the best practice for the 2nd and 3rd questions would depend on whether or not the CAD has integrated libraries. (more) |
— | 7 months ago |
| Edit | Post #286035 |
Post edited: just piling up reference material |
— | 7 months ago |
| Comment | Post #289483 |
Get an internship at a company. You'll get exposure to an industry-grade project in an industrial environment. (more) |
— | 8 months ago |
| Edit | Post #289483 | Question closed | — | 8 months ago |
| Edit | Post #289482 |
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— | 8 months ago |
| Edit | Post #289482 | Initial revision | — | 8 months ago |
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A: Essential safety features of an EMG/medical grade device? > What are the essential safety features of such types of hardware? > One option to make such hardware safer is to make it battery powered. What other safety features are generally recommended? The answer to these questions are in the IEC 60601 standard. If you are involved in electrical... (more) |
— | 8 months ago |
| Comment | Post #285993 |
Wilkins, what were the circumstances when your experienced friends shared their opinion about professional vs. hobbyist software? What kinds of boards or products are you and your friends designing? Were you all deciding what software to use for your next project? Were you asking them what softwar... (more) |
— | 9 months ago |
| Edit | Post #289344 | Initial revision | — | 9 months ago |
| Answer | — |
A: Correct way to think about thermal noise? > If a data sheet gives the thermal noise (of +3/-3 standard deviations) as 1 uVpp does it mean that out of every thousand samples, 3 will have noise more than ±1 uV at any sample rate? 1000 sps will lead to 3 samples having more than ±1uV noise in a second, 2000 sps will lead to 6 samples having mo... (more) |
— | 9 months ago |
| Comment | Post #288720 |
[The meta reputation has been bugging me for a while.](https://meta.codidact.com/posts/278928) Thanks for taking care of this! (more) |
— | 9 months ago |