Activity for Olin Lathrop
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #290875 | Initial revision | — | 9 months ago |
| Answer | — |
A: PCB as a wall of an underwater enclosure I guess it would work. I have used electrodes on a PCB to detect whether water level got high enough to turn on a sump pump. It worked, although it hasn't been installed very long. In that case the PCB extends upwards to where it is dry. That's where wires are soldered that go to the detection ... (more) |
— | 9 months ago |
| Comment | Post #290863 |
What you are asking can't be answered without knowing the purpose of each connection to ground. We need to see both the layout (which you provided) and the schematic. (more) |
— | 9 months ago |
| Edit | Post #290839 | Initial revision | — | 9 months ago |
| Article | — |
Phone fix adventure case study I've had a Nexus 5X smart phone since 2016, so now in Feb 2024 it's almost 8 years old. I like the phone and have had no problems with it until three days ago. I had it in the car plugged in and connected as usual when I noticed it rebooting. I thought that was a bit odd, but figured maybe that wa... (more) |
— | 9 months ago |
| Comment | Post #290785 |
@#8062: <i>"initially it could provide 10-15 minutes of runtime"</i>. Where did you see this? I looked all over for such a spec, but didn't find it. I checked in the user manual and on the web page the device was sold from. The web page just has a dash where the runtime would be (see above), and ... (more) |
— | 9 months ago |
| Comment | Post #290779 |
@#8049: Yes, there is more to it than just Ah capacity. However, it's a start, and I was trying to keep things simple. (more) |
— | 9 months ago |
| Edit | Post #290785 | Initial revision | — | 9 months ago |
| Answer | — |
A: Why would a standby UPS fail to power devices when there's no power outage? Now that you've supplied a link to the product, I can provide a different take on this affair. Your "UPS" is an Amazon Basics model described at https://www.amazon.com/gp/product/B073Q3BSPG/?th=1. First, it's clear that unit is optimized for one parameter only, which is minimum possible price whi... (more) |
— | 9 months ago |
| Edit | Post #290774 |
Post edited: Edited link from a comment into the question |
— | 9 months ago |
| Edit | Post #290779 | Initial revision | — | 9 months ago |
| Answer | — |
A: Why would a standby UPS fail to power devices when there's no power outage? I see that manassehkatz has already given you a good answer and plausible explanation for what you observed, so I'll fill in a few other points. Your battery is 5 years old, so is getting to the point where it could start to fail. I wouldn't expect a 5 year old battery to be bad, but it's to the ... (more) |
— | 9 months ago |
| Comment | Post #290720 |
You are assuming the domed buttons are capacitive switches. Maybe they are, but I wouldn't rule out that they are simple mechanical contacts. In all the products I've worked on that had these kinds of domed buttons, they were just switches. The on-resistance was up to about 200 Ω or so. I c... (more) |
— | 10 months ago |
| Edit | Post #290689 | Initial revision | — | 10 months ago |
| Answer | — |
A: What type of button is this on a remote control Such a domed button is usually called a "membrane switch", at least here in the US. As you say, the small metal bubble makes contact with something underneath when pressed. Advantages of membrane switches over the capacitive or conductive sense switches in the rest of your remote include better e... (more) |
— | 10 months ago |
| Edit | Post #290601 |
Post edited: |
— | 10 months ago |
| Edit | Post #290601 | Initial revision | — | 10 months ago |
| Answer | — |
A: estimation of pogo pin resistance Is there a scientific way to estimate the resistance of a pogo pin? Ultimately there must be, but it generally requires knowing things you don't know. Worrying about the resistance of the barrel and spring is missing the point. The limiting factor will be the small contact area between the cir... (more) |
— | 10 months ago |
| Edit | Post #290595 | Initial revision | — | 10 months ago |
| Answer | — |
A: High voltage transformer design When should a transformer core be potted? Whenever you need some of Mechanical ruggedness. High dielectric strength. Minimize vibrations (and therefore audible whine) from capacitive, inductive, piezo-electric and magneto-restrictive effects. Can I place the high voltage conductors... (more) |
— | 10 months ago |
| Comment | Post #290541 |
Yes, if you isolate the TX and RX signals, then you get around the bi-directional problem. Now you have to isolate at each interface to the bus, though. (more) |
— | 11 months ago |
| Edit | Post #290541 | Initial revision | — | 11 months ago |
| Answer | — |
A: Most reliable galvanic isolation technology for extreme EMI environments? My first knee-jerk reaction was to use opto-isolators. There are some that have been around for decades and are unlikely to go obsolete any time soon. I wasn't previously aware of these "digital isolators". They seem like they go thru a lot of trouble to ultimately do what opto-isolators do. I'... (more) |
— | 11 months ago |
| Edit | Post #290501 |
Post edited: |
— | 11 months ago |
| Comment | Post #290499 |
That literally translates to "music closet", which seems to mean a stand-alone cabinet with assorted audio gear. Apparently that includes a radio, at least in your case. (more) |
— | 11 months ago |
| Edit | Post #290501 |
Post edited: |
— | 11 months ago |
| Edit | Post #290501 | Initial revision | — | 11 months ago |
| Answer | — |
A: Weird grounding on a vintage hifi sideboard It has two female inputs on the backside that are labeled as "Grounding". This is incorrect. Imagealttext Take a closer look at the two connections and you will see that the left is labeled "Antenne" and the right "Erde". That's German for antenna and ground. Symbols for antenna and groun... (more) |
— | 11 months ago |
| Comment | Post #290499 |
What's a "hifi sideboard"? (more) |
— | 11 months ago |
| Edit | Post #290448 | Post undeleted | — | 11 months ago |
| Comment | Post #290448 |
I'm not following all your calculations, but I can see that you are not carrying units properly thru all the computations. In several places you show dimensionless quantities on one side of an equation, with units inexplicably appearing on the other side. That's clearly wrong.
Don't be so sloppy... (more) |
— | 11 months ago |
| Comment | Post #290416 |
Actually the nominal difference from CANH to CANL is only 1.8 V with the bus in dominant state. In any case, I wasn't suggesting to run the LED directly off the CAN bus. I was expecting the other end of the resistor driving a transistor or something. I assumed the OP was planning that considering ... (more) |
— | 12 months ago |
| Edit | Post #290414 | Post undeleted | — | 12 months ago |
| Edit | Post #290416 | Initial revision | — | 12 months ago |
| Answer | — |
A: CAN BUS monitoring with a LED CAN lines in the most common implementation have 60 Ω impedance between them. Anything that is substantially larger than that won't effect the lines much. I'd use 1 kΩ at least, preferably more. The lead from the bus line to the resistor must also be short to minimize the characteristi... (more) |
— | 12 months ago |
| Comment | Post #290354 |
Those ICs don't usually make +-12 V, even with 5 V in. They usually have a two-stage charge pump, so you'll get +-10 V minus a little loss. (more) |
— | 12 months ago |
| Edit | Post #290357 |
Post edited: |
— | 12 months ago |
| Edit | Post #290357 | Initial revision | — | 12 months ago |
| Answer | — |
A: Converting 5V to ±12V You say the only thing that will be powered by the ±12 V supplies is a comparator. The first thing I would look at is whether you really need the comparator to run from that voltage range. Presumably you are asking for ±12 V because that is the range of the signals being compared. ... (more) |
— | 12 months ago |
| Edit | Post #290333 | Initial revision | — | 12 months ago |
| Answer | — |
A: Noise from oscillator on top layer to clock on bottom layer with VCC & GND layers between It's hard to answer your specific case since you didn't label the layers in your picture, or which traces are doing what. That said, a few traces crossing each other on different layers is not much coupling. In most cases of a typical board with a typical "SPI clock signal", there won't be any pr... (more) |
— | 12 months ago |
| Edit | Post #290331 | Initial revision | — | 12 months ago |
| Answer | — |
A: What fabrication process is being used for jellybean parts I want to know why the top-of-the-line CPUs and GPUs from Intel, NVIDIA, and AMD are all bragging about the fabrication process (7nm and 5nm) and trying to be consistently smaller. It's marketing hype intended to make them look more high tech than the other guy. There is little reason the end use... (more) |
— | 12 months ago |
| Comment | Post #290284 |
The analog filter rolloff is around 9 Hz, so 60 Hz should be about 16 dB down. Power frequency here in North America is 60 Hz. There will always be some power line noise, but shouldn't effect settling time. (more) |
— | 12 months ago |
| Comment | Post #290284 |
Errors in software are always possible, but the same software exhibits much longer settling times at lower resistances, and these vary by capacitor. (more) |
— | 12 months ago |
| Edit | Post #290284 |
Post edited: |
— | 12 months ago |
| Edit | Post #290284 | Initial revision | — | 12 months ago |
| Question | — |
Ceramic capacitor "memory" effect? I have run into an interesting phenomenon related to ceramic capacitors. This question is part of the effort to understand the issue, and eventually work around it. But first, some background of this particular situation is required. Device background I have designed a high-accuracy 32-channe... (more) |
— | 12 months ago |
| Edit | Post #290172 |
Post edited: |
— | about 1 year ago |
| Edit | Post #290172 | Initial revision | — | about 1 year ago |