Activity for Lundin
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #280675 |
@Chupacabras Did you try the above mentioned XR46010ISBTR? Looks fairly compatible, though I'd double check the pinout because SOT-23 pin numbers aren't that well standardized. (more) |
— | almost 4 years ago |
| Comment | Post #280672 |
@Chupacabras The 90mA current is an odd case, most LEDs are rated at 20mA. Also, you can get extreme super bright LEDs that shine like the sun with several candela at 20mA, why focusing on the LED is easier. (more) |
— | almost 4 years ago |
| Comment | Post #280672 |
It looks like a board where anything can fail at any moment though... Anyway, why not just pick a brighter LED? So much easier. (more) |
— | almost 4 years ago |
| Comment | Post #280672 |
Hmm, I don't think failing parts is necessarily the problem given the pics. The solder job is truly awful and besides you got corrosion of some kind all over, to the point where I would suspect that the board is water damaged. (more) |
— | almost 4 years ago |
| Comment | Post #280713 |
You can easily answer this by not connecting the probe ground to the DUT and measure something, then connect the ground and measure again. The signal that looks like crap is the one that you don't want. (more) |
— | almost 4 years ago |
| Comment | Post #280675 |
@Chupacabras As noted, this was a PNP part but you need N-channel. Just search for SOT23 LED Driver and you get plenty of results. If you wish the exact part, then you have to put more effort into the question, adding the print on the IC and preferably also a photo. (more) |
— | almost 4 years ago |
| Edit | Post #280672 |
Post edited: |
— | almost 4 years ago |
| Comment | Post #280675 |
Closest match on Mouser appears to be XR46010ISBTR with NPN. SOT-23 pinout standardization leaves a lot to be desired though, so I'd be very careful double-checking the pins of your layout symbol vs datasheet. Don't trust the schematic pin numbers. (more) |
— | almost 4 years ago |
| Edit | Post #280675 |
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— | almost 4 years ago |
| Edit | Post #280675 |
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— | almost 4 years ago |
| Suggested Edit | Post #280672 |
Suggested edit: (more) |
helpful | almost 4 years ago |
| Edit | Post #280675 |
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— | almost 4 years ago |
| Edit | Post #280675 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: Name of this current limiting device It is some manner of BJT or MOSFET LED driver similar to for example this: NCR402T (just a random example, this one was PNP). They are literally called "SOT23 LED driver" (Mouser calls them "SOT23-3 LED Lighting driver"). Which exact part you have, I can't tell without marking. Plenty of manufact... (more) |
— | almost 4 years ago |
| Comment | Post #280672 |
Is R1 really 1 ohm? Then what purpose does it fill? (more) |
— | almost 4 years ago |
| Comment | Post #280595 |
Semiconductor companies in general and NXP in particular let their "FAE" play around with evaluation boards and write app notes on their spare time. That is, engineers with incredibly broad but rather shallow knowledge. Mostly these should be regarded as some hints to get people started (with the com... (more) |
— | almost 4 years ago |
| Comment | Post #280586 |
As for the question "what is AC frequency", that's a valid question. Alternating currents means you have several phases (simply put: several signals/wires) between which the current alternates. The current in each phase comes as a sine wave and the "AC frequency" is simply the (2*PI) period of the si... (more) |
— | almost 4 years ago |
| Comment | Post #280586 |
This entirely depends on what motor that sits inside the oven and how it was designed. I wouldn't assume that every microwave that has ever been made is using the same kind of motor. You'll have to come up with some manner of partnumber or preferably a datasheet of the motor, or I don't think this qu... (more) |
— | almost 4 years ago |
| Comment | Post #280582 |
@Olin Lathrop I don't think there's any relation between the number of categories and the site activity. That site like several others struggles because it had too few veteran/enthusiast users from the start. That being said, we aren't exactly drowning in new posts either, so yeah maybe we should wa... (more) |
— | almost 4 years ago |
| Comment | Post #280582 |
@Olin Lathrop The benefit of a different category is that we can apply different posting rules there. For example if someone wants help to trouble-shoot their program, we'll want a minimum code example and/or the relevant schematic page only. However, if they are looking for a design review we might ... (more) |
— | almost 4 years ago |
| Edit | Post #280582 |
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— | almost 4 years ago |
| Edit | Post #280582 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: How about a new section for code reviews? Regarding scope of embedded systems/firmware When we released Software Development, I made a push to make all forms of embedded systems programming off-topic and re-direct such to this site. The reason for this is is my experience from the "embedded" tag over at SO, where I'm one of the top use... (more) |
— | almost 4 years ago |
| Comment | Post #280564 |
@ Monica Cellio Embedded systems programming is currently off-topic at Software Development but on-topic here. (more) |
— | almost 4 years ago |
| Comment | Post #280479 |
The 6A current limit sounds like hogwash. The human body has too high resistance to ever get close to currents like that. And the currents are what matter here, not the voltages. (more) |
— | almost 4 years ago |
| Comment | Post #280479 |
(Disclaimer: I don't know much about medicine save for a CPR class.) To stop the heart you just need to make the (I think they are called) beta receptors freak out, which only takes a relatively small current. These control the heart rhythm and if they stop acting reliable you get a heart failure. Th... (more) |
— | almost 4 years ago |
| Comment | Post #280454 |
The way I usually do this is to buy pre-programmed MCUs for high volume products ~1000pcs/year, keep the SWD connector footprint on the board but don't mount it. For products of lower volumes or products where you expect a lot of software releases, keep the connector and use an in-circuit programmer.... (more) |
— | almost 4 years ago |
| Comment | Post #280450 |
@Olin Lathrop Maybe he was rather holding on to a metal truck chassis shorted to 700kV while touching the ground with another body part. Though I suppose you need quite a big clearance distance for 700kV, several meters perhaps. (more) |
— | almost 4 years ago |
| Comment | Post #280454 |
Also, justifying development costs of pogo pins, bootloaders etc means that you must have large volumes. Engineers cost money. How many 2x5 1.27mm SWD connectors can you buy for the engineer salary required to develop this? Almost certainly far more than a product life time of such connectors. (more) |
— | almost 4 years ago |
| Comment | Post #280454 |
"I don't feel ready to commit to having the chips pre-programmed" Why not? This is no effort at all, you just contact a company dealing with such parts, give the binary to them (NDA if necessary) and buy the pre-programmed MCUs from them instead of the silicon vendor. There's usually no big MOQ. (more) |
— | almost 4 years ago |
| Comment | Post #280450 |
As for your grandfather's story, it sounds like hogwash. For something to actually catch fire, you would need several Ampere running through it. The resistance of the human body + clothes, shoes (likely rubber) etc + the ground itself, is many Megaohms. So even if someone manages to charge their body... (more) |
— | almost 4 years ago |
| Comment | Post #280450 |
As for why a certain voltage is used... the aim of an electric chair isn't to burn someone to crisp by making their whole body a conductor for high current, that would be extremely unethical and similar to burning someone alive. (more) |
— | almost 4 years ago |
| Comment | Post #280450 |
@Olin Lathrop Well... nobody _has_ to design them. Engineers with some sort of moral code might refuse to do so. But I agree that questions regarding why a certain voltage is used by certain electrical equipment are on-topic here. (more) |
— | almost 4 years ago |
| Edit | Post #280415 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: What should rep gain/loss be on Papers? I think they should have the same rep as ordinary posts. If they are high quality they will eventually accumulate a lot of up-votes over time. That's how the voting system is supposed to work, rewarding quality over time. I have written lots of similar detailed papers or self-answered Q&A on SO an... (more) |
— | almost 4 years ago |
| Comment | Post #280394 |
Yeah the TVS part should perhaps have been posted as a separate question. (more) |
— | almost 4 years ago |
| Comment | Post #280393 |
@Pete W Yeah indeed, I'll already have some 33V TVS elsewhere in the BOM. As for replacing the relay, indeed some manner of SSR-like solution is preferable (faster, cheaper, more reliable). There's various "smart high side drivers" that are very good for this and they can also drive analog signals. ... (more) |
— | almost 4 years ago |
| Comment | Post #280394 |
Thanks for your reply. Regarding the TVS it would be 30V-something zener breakdown voltage, mounted with the anode towards ground. The use-case I had in mind is something like an industrial/automotive application with a fairly long cable (3-5m) between the driver circuit on the PCB and the actual coi... (more) |
— | almost 4 years ago |
| Comment | Post #280392 |
That _is_ strange. I'm guessing they got the scale of y axis of the graph wrong. Because if the sensor was truly as good as that graph showed, you can be sure they would have advertised it. (more) |
— | almost 4 years ago |
| Edit | Post #280393 | Initial revision | — | almost 4 years ago |
| Question | — |
What should be considered when picking a flyback diode? Which are the parameters I should looking for when picking a flyback diode to be placed across a generic coil, such as a relay? That is: a coil with plain on/off functionality, for example a 24VDC relay coil with 700mW max coil power. I assume that these are the important ones: - Power dissipat... (more) |
— | almost 4 years ago |
| Comment | Post #279987 |
After 5 consecutive then there must be a stuff bit. (more) |
— | almost 4 years ago |
| Edit | Post #279978 |
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— | almost 4 years ago |
| Edit | Post #279990 |
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— | almost 4 years ago |
| Comment | Post #279987 |
CAN (and UART) utilizes bit stuffing, so you won't get 9 adjacent zeroes or there will be a stuff error. (more) |
— | almost 4 years ago |
| Edit | Post #279990 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: CAN Bus - Internal Oscillator Check out What are the most common causes of CAN bus communication errors? As stated there, CAN requires a clock accuracy of 1.58% or your CAN node is non-compliant. I would recommend to use <1% however, which usually means external quartz. Some MCUs have good enough internal RC oscillators, your ... (more) |
— | almost 4 years ago |
| Suggested Edit | Post #279978 |
Suggested edit: (more) |
helpful | almost 4 years ago |
| Comment | Post #279886 |
@Michaël Bensimhoun I don't know, hence the question. I was thinking of aluminium electrolytes but I guess the cap chemistry matters a lot? (more) |
— | about 4 years ago |
| Comment | Post #279886 |
Curious that you mention bypass caps in the context of ESD, since a discharge is a extreme spike event, unlike the average EMI. To what extent do they help against ESD, aren't they generally far too slow, compared to TVS diodes etc? (more) |
— | about 4 years ago |