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Search - "high power usage"
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Woohoo! 32k achieved!!! Finally I can post some new rant without risking some sudden overshoot 😁
So putting celebrations aside for a minute, a while ago I've noticed a tingle when I stroke my finger across metal areas of my tablet, or the sides of my phone (which probably has metal near it too) while it's charging. And it's been bugging me ever since.
Now, some things to note are that it only happens when my feet are touching the ground though slippers, and that the frequency is so low that I can actually feel the tingle when I slide my finger across the material. This to me at least seems like electricity flows through me into ground, and touching the ground directly provides a path so easy for the electrons to run away that I don't feel it at all. But if I lift my feet off the ground entirely, I just get charged up and after that, nothing else happens.
So those are my ideas. The answers on the subject on the other hand.. absolute cancer. Unsurprisingly, most of them came from Apple users. Here's some of them.
https://discussions.apple.com/threa...
- I've not noticed it, but if you're concerned bring the phone to Apple for evaluation.
- Me too facing same problem.. did u visit apple care?
And one good answer at least...
- google emf sensitivity, its real. You are right, there is a small current flowing through your body, try to limit your usage. The problem with this issue is those who aren't affected (lucky ones for now) will tell you these products are 100% safe. To a degree they are, i used my ipod touch for about 2 years straight vwith virtually no symptoms. then the tingling started and it gets worse.You will get more sensitive to progressively less powerful things. I dont want to scare you but just limit your usage like i didnt do 🙂
Overall that discussion was pretty good actually, aside from "bring it to the Genius Bar, they'll know for sure and not just sell you another unit". But then there's Reddit.
https://reddit.com/r/iphone/...
- Ok, real reason is probably that the extension cord and/or outlet is probably not grounded correctly. Either that or you are using a cheap knockoff charger.
Either use a surge protector and/or use the authentic Apple Charger.
- It's not the volts that hurt you, it's the amps
- I think you are in deep love with your phone. That tingling sensation is usually referred to as "love" in human language.
- Do less acid, I would advise.
Okay, so that's the real cancer. Grounding issue sounds reasonable despite it being wrong. Grounding is actually not needed when your charging appliance doesn't have any exposed metal parts. And isolation from high voltage to low voltage side actually happens through things like routering holes into the PCB, creating spark gaps, and using galvanic isolation through things like optocouplers. As for a surge protector? I'm using them to protect my PC and my servers, but the only purpose they serve is to protect from.. you guessed it.. voltage surges, like lightning bolts hitting the grid. They don't do shit for grounding or reducing this tingle! What a fucking tool.
It's not the volts that kill, it's the amps.. yeah I'm sure that the debunking of that is easy to find. Not gonna explain that here. And the rest of it.. yeah it's just fucking cancer.
Now what's the real issue with this tingle? It's actually a Class-Y rated (i.e. kV rated) capacitor that's on the transformer of any switch-mode power supply, including phone chargers. If memory serves me right, it helps with decoupling the switching noise and so on. But as it's connected to the primary side of the transformer, if the cap is sufficiently large and you are sufficiently sensitive, it can actually cause that tingle by passing a fraction of the mains electricity into your body. It's totally safe though, as the power that these caps pass is very small. But to some, it's noticeable.
Hope you found this interesting! And thanks a lot for bringing me to 2^15. I really appreciate it ♥️15 -
So probably about a decade ago at this point I was working for free for a friend's start-up hosting company. He had rented out a high-end server in some data center and sold out virtualized chunks to clients.
This is back when you had only a few options for running virtual servers, but the market was taking off like a bat out of hell. In our case, we used User-Mode Linux (UML).
UML is essentially a kernel hack that lets you run the kernel in user space. That alone helps keep things separate or jailed. I'm pretty sure some of you can shed more light on it, but that's as I understood it at the time and I wasn't too shabby at hacking the kernel when we'd have driver issues.
Anyway, one of the ways my friend would on-board someone was to generate a new disk image file, mount it, and then chroot to that mount path. He'd basically use a stock image to do this and then wipe it out before putting it live.
I'm not sure exactly what he was doing at the time, but I got a panicked message on New Years Day saying that he had deleted everything. By everything, he had done an rm -fr /home as root on what he had thought was the root of a drive image.
It wasn't an image. It was the host server.
In the stoke of a single command, all user data was lost. We were pretty much screwed, but I have a knack for not giving up - so I spent a ton of time investigating linux file recovery.
Fun fact about UML - since the kernel runs in user space as a regular ol' process, anything it opens is attached to that process. I had noticed that while the files were "gone", I could still see disk usage. I ended up finding the images attached to their file pointers associated with each running kernel - and thankfully all customers were running at the time.
The next part was crazy, and I still think is crazy. I don't remember the command, but I had to essentially copy the image from the referenced path into a new image file, then shutdown the kernel and power it back on from the new image. We had configs all set aside, so that was easy. When it finally worked I was floored.
Rinse and repeat, I managed to drag every last missing bit out of /proc - with the only side effect being that all MySQL databases needed to be cleaned up.3 -
I had spent the last year working on a online store power by woocommerce with over 100k products from various suppliers. This online store utilized a custom API that would take the various formats that suppliers offer their inventory in and made them consistent. Now everything was going swimmingly initially, but then I began adding more and more products using a plug-in called WP all import. I reached around 100k products and the site would take up to an entire minute to load sometimes timing out. I got desperate so I installed several caching plugins, but to no avail this did not help me. The site was originally only supposed to take three to four months but ended up taking an entire year. Then, just yesterday I found out what went wrong and why this woocommerce website with all of these optimizations was still taking anywhere from 60 to 90 seconds to load, or just timing out entirely. I had initially thought that I needed a beefier server so I moved it to a high CPU digitalocean VM. While this did help a little bit, the site was still very slow and now I had very high CPU usage RAM usage and high disk IO. I was seriously stumped the Apache process was using a high amount of CPU and IO along with MYSQL as well. It wasn't until I started digging deeper into the database that I actually found out what the issue was. As I was loading the site I would run 'show process list' in the SQL terminal, I began to notice a very significant load time for one of the tables, so I went to go and check it out. What I did was I ran a select all query on that particular table just to see how full it was and SQL returned a error saying that I had exceeded the maximum packet size. So I was like okay what the fuck...
So I exited my SQL and re-entered it this time with a higher packet size. I ran a query that would count how many rows were in this particular table and the number came out to being in the millions. I was surprised, and what's worse is that this table belong to a plugin that I had attempted to use early in the development process to cache the site. The plugin was deactivated but apparently it had left PHP files within the wp content directory outside of the actual plugin directory, so it's still executing scripts even though the plugin itself was disabled. Basically every time I would change anything on the site, it would recache the whole thing, and it didn't delete any old records. So 100k+ products caching on saves with no garbage collection... You do the math, it's gonna be a heavy ass database. Not only that but it was serialized data, so when it did pull this metric shit ton of spaghetti from the database, PHP then had to deserialize it. Hence the high ass CPU load. I had caching enabled on the MySQL end of things so that ate the ram. I was really desperate to get this thing running.
Honest to God the main reason why this website took so long was because the load times made it miserable to work on. I just thought that the hardware that I had the site on was inadequate. I had initially started the development on a small Linux VM which apparently wasn't enough, which is why I moved it to digitalocean which also seemed to not be enough, so from there I moved to a dedicated server which still didn't seem to be enough. I was probably a few more 60-second wait times or timeouts from recommending a server cluster to my client who I know would not be willing to purchase it. The client who I promised this site to have completed in 3 months and has waited a year. Seriously, I would tell people the struggles that I would go through with this particular site and they would just tell me to just drop the site; just take the money, just take the loss. I refused to, this was really the only thing that was kicking my ass. I present myself as this high-and-mighty developer like I'm just really good at what I do but then I have this WordPress site that's just beating the shit out of me for a year. It was a very big learning experience and it was also very humbling as well, it made me realize that I really don't know as much as I think I might. It was evidence that there is still so much more to learn out there, I did learn a lot from that experience especially about optimizing websites the different types of methods to do that particular lonely on the server side and I'll be able to utilize this knowledge in the future.
I guess the moral of the story is, never really give up. Ultimately things might get so bad that you're running on hopes and dreams. Those experiences are generally the most humbling. Now I can finally present the site that I am basically a year late on to the client who will be so happy that I did not give up on the project entirely. I'll have experienced this feeling of pure euphoria, and help the small business significantly grow their revenue. Helping others is very fulfilling for me, even at my own expense.
Anyways, gonna stop ranting. Running out of characters. If you're still here... Ty for reading :')7