Mac: Suddenly turns off
Me: Fuck my code..F***
Mac: No response at all
Me: reset SMC etc etc
Mac: I am dead (no battery detection, dies after 10 min on power adaptor)
Me: Skips a heart beat..(Git, oh yea git)

**Takes Mac to store, After diagnosis**

Apple Freaking Genius (AG): Your Mac has a mother board problem it needs to be replaced.
Me: Hmm what is the problem exactly??
AG: Issues in logic board and some other components.
Me: How much?
AG: Out of warranty so $$$ (60% of original amount)
Me: (wtf?) Really
AG: It's entire motherboard replacement .. bla bla

**Bring it home > open > everything seems ok on multimeter as per circuit diagram > finally finds a voltage drop that is not consistent > minute short circuit > remove > check further > nothing else > reassemble > hit power button > starts fine > freaking battery detected > works fine**

0 $ repair

Fixes two more devices @ 0 $ in friend circle

Builds a raspberry pi backup laptop with 3d printed body..Ubuntu.. you know can't live without a computer

#ThugLife #Engineer

A couple of years ago, I was working in a computer shop as a "technician", I was 15, first job I ever had.
One day an elderly lady came into the shop, probably 50'ish, she and her whole family "suffered" from electromagnetic radiation, and the mother had the worst suffering. She complained about her TV box that just had died.

I accept the tuner and see it's wrapped with 10 layers of aluminium foil, with a tiny hole for the IR receiver.

The whole box smells like burnt electronics, and the foil gets darker for each layer I unwrap. I try explain to her that the box gets warm and overheated by wrapping it like this, and she's lucky that it didn't catch fire.

I further explain to her that she will not get a new box, because the warranty does not cover _this_. The mother tells me she has to wrap it like this, because she gets headaches when she's watching the news.

She then proceeds to go into a rage mode and gets her whole family into the shop, where all of them starts yelling at me, the younger kids start throwing stuff down from the shelves and touching the TVs with sticky fingers (literally, sticky, like yuck!).

Unsure what to do, boss is in a meeting, and my colleague is busy in the back.

So I calmly tell them that in this building there's 4 wireless networks, 3 wireless phones, high voltage cables run in the wall behind me, there's factory tracks 20 meters behind the building, next door business is an electrician, you're standing in front of wall with 30-40 TVs, 5 HDMI splitters, 3 TV boxes and a Blu-ray player. And they've all been standing in front of them for the last 10 minutes.

They all suddenly feel really sick and run out of the store, never to be seen again. From that day, I decided I'll never work in a shop again, and pursued my dreams to become a developer.

TL;DR: Family is "sensitive" to electromagnetic radiation, almost put burnt down their house because of stupidity, yelled at me. I decided to pursue my dream as a developer.

So this was a couple years ago now. Aside from doing software development, I also do nearly all the other IT related stuff for the company, as well as specialize in the installation and implementation of electrical data acquisition systems - primarily amperage and voltage meters. I also wrote the software that communicates with this equipment and monitors the incoming and outgoing voltage and current and alerts various people if there's a problem.

Anyway, all of this equipment is installed into a trailer that goes onto a semi-truck as it's a portable power distribution system.

One time, the computer in one of these systems (we'll call it system 5) had gotten fried and needed replaced. It was a very busy week for me, so I had pulled the fried computer out without immediately replacing it with a working system. A few days later, system 5 leaves to go work on one of our biggest shows of the year - the Academy Awards. We make well over a million dollars from just this one show.

Come the morning of show day, the CEO of the company is in system 5 (it was on a Sunday, my day off) and went to set up the data acquisition software to get the system ready to go, and finds there is no computer. I promptly get a phone call with lots of swearing and threats to my job. Let me tell you, I was sweating bullets.

After the phone call, I decided I needed to try and save my job. The CEO hadn't told me to do anything, but I went to work, grabbed an old Windows XP laptop that was gathering dust and installed my software on it. I then had to build the configuration file that is specific to system 5 from memory. Each meter speaks the ModBus over TCP/IP protocol, and thus each meter as a different bus id. Fortunately, I'm pretty anal about this and tend to follow a specific method of id numbering.

Once I got the configuration file done and tested the software to see if it would even run properly on Windows XP (it did!), I called the CEO back and told him I had a laptop ready to go for system 5. I drove out to Hollywood and the CFO (who was there with the CEO) had to walk about a mile out of the security zone to meet me and pick up the laptop.

I told her I put a fresh install of the data acquisition software on the laptop and it's already configured for system 5 - it *should* just work once you plug it in.

I didn't get any phone calls after dropping off the laptop, so I called the CFO once I got home and asked her if everything was working okay. She told me it worked flawlessly - it was Plug 'n Play so to speak. She even said she was impressed, she thought she'd have to call me to iron out one or two configuration issues to get it talking to the meters.

All in all, crisis averted! At work on Monday, my supervisor told me that my name was Mud that day (by the CEO), but I still work here!

Here's a picture of the inside of system 8 (similar to system 5 - same hardware)

I want to stop charging my e-scooter at around 85% because this will increase the battery life. To avoid always having to pull the plug at the right level, I made a stop circuit that goes between charging brick and e-scooter.

There's no processor involved, just a CMOS 555 used as inverting Schmitt Trigger which controls a power mosfet. Also two status LEDs and a start switch. The poti adjusts the cut-off level. Worked on first try, with only manual voltage and tolerance calculations beforehand!

Recently I've been upgrading ubuntu. It took almost midnight.

Suddenly my area witnessed low voltage.

That woke up my dad.

(Now the funny part)

He looked at my laptop. Ordered me to stop whatever is running on it.

Naturally, I asked why!

No response.

Next morning, I came to know my dad thought those gibberish commands running on terminal caused that voltage to drop.

I laughed like hell...
(Me infornt of dad - hackerman)

(Not that funny tho)
Fin.

Long rant ahead. Should take about 2-3 minutes to read. So feel free to refill your cup of coffee and take a seat :)

It turns out that the battery in my new Nexus 6P is almost dead. Well not that I didn't expect that, the seller even explicitly put that in the product page. But it got me thinking.. why? Lithium batteries are often good for some 10k charges, meaning that they could last almost 30 years when charged every day! They'd outlive an entire generation of people!

Then I took a look at the USB-C wall charger that Huawei delivered with this thing. A 5V 3A brick. When I saw that, I immediately realized.. aah, that's why this battery crapped out after a mere 2 years.

See, while batteries are often advertised as capable of several amps (like 7A with my LiitoKala 18650 batteries that I often use in projects), that's only the current that they can safely take or deliver without blowing up. The manufacturer doesn't make this current rating with longevity in mind. It's the absolute maximum in current that a given battery can safely handle.

The longevity on the other hand directly depends on the demand that's placed on the battery. 500mA which is standard USB 2.0 rating or 1A which is standard USB 3.0 rating, no sweat. The battery will live for at least a decade of daily charges and discharges like that no problem.

But when you start shoving 3A continuous into a battery, that's when it will suffer. Imagine that your current workload is 500mA and suddenly you get shoved 6 times that work upon you. How long would you last?

Oh and not only the current is a problem, I suspect that it also overvolts the battery to maintain a constant current all the way till the end. When I charged my lithium cells with my lab bench power supply, the battery would only take a few milliamps when it got close to the supply voltage. Quick bit of knowledge: lithium cells are charged at constant current first, then when the current drops below that, it continues at constant voltage - usually 4.2 or 4.35V depending on the battery. So you'd set your lab bench power supply at 4.2V 500mA. But in that constant voltage mode, as the battery's voltage and the supply's voltage equalize, the current drops because the voltage difference becomes lower. Remember, voltage is what causes current to flow. Overvolting at the supply to stay in constant current mode all the way till the end speeds this process up but can be dangerous and requires constant monitoring of the battery voltage.

So, why does Huawei and a bunch of other manufacturers make these 3A power chargers? Well first it's because consumer demands ever more, regardless of the fact that they can just charge at 500mA for the night (8h of sleep) and charge a 4000mAh battery from 0 to 100% no problem. Secondly it's because sometimes you need that little bit of extra juice fast, like when you forgot to plug the damn thing in and you've got only 30 minutes in the morning to pour some charge into it.

But people use those damn fucking things even when they go to bed, making that 3A torture a fucking standard process!! And then they complain that their batteries go to shit?!

Hopefully this now made you realize that the fast charger shouldn't be used as a regular charger ^^

A new toy arrived today. Time to go back to soviet russia and have some fun!!

After my previous PC bursting into flames when I changed my input voltage to 120v on the power supply my dad never bought me one again this happened when I was aged 12. I was so much in love with computers that I would visit my friends who had ones at home and not leave till their moms asks me to. I remember collecting my lunch money and buying a Pentium 4 mb for dog cheap at a local store and as soon as I plugged in the mb short-circuited and died (I had the other parts as I was scavenging the junk yard for them). I'll never forget the moment I burst into tears seeing my hopes for a PC dieing. So after all the years passing when I was 16 I spent my whole summer vacation working in a construction site doing so much heavy work. There were days that my body couldn't bear and I just fell but somehow by the end of that summer I managed to collect enough money to assemble this 3rd gen dual-core. This is my baby. I'm using it till this date.
**Sorry about the bad English

Dells XPS are made of magic. [long story, major fuckup, 10k+ damages]

It all started in December. One morning I was late to work, drove there as fast as possible. (I live like 3 minutes away so me being late really meant *late*) Parked my car in a secluded car park, grabbed my backpack and ran to work. The car park is like 100 meters away from work so I took my feet into my hands and ran. Next thing I know my heels loose all grip while I go down a small slope and I drop on my back full force. On a sharp edged stone. With only my 1700$ XPS in it. Fuck.

I paniced, but got up and ran to work. I checked on the notebook, praying it would boot. It booted! Holy shit. I flipped the notebook and saw two small dents in the aluminum shell. I was thorougly impressed. I later discovered that it left a small shadow on the display, but given what a hit that was (I am not exactly a lightweight), impressive would be a massive understatement.

Fast forward to February, I am weighing my options to get the screen replaced maybe, as damage on my hardware (even if neglectable) triggers some sort of OCD and makes me feel bad 24/7. Also my laptop tends to shut off from time to time, looked into the Event Viewer and saw kernel panic. I figured that the battery probably still took a hit and that it drops voltage from time to time and the kernel assumes a critical situation, thus shutting off.

It stayed quite snowy in Austria up until March, so occasional snowing wasn't rare. Got out of work one day, saw it snowed a bit. Whatever. I had my moms car at the time, so I tried if it would slide a bit if I donut on the now (5pm) empty parking space. Nothing. Drove done a small hill, ABS triangle lit up red (board computer can't outbalance the snow). I drove out to the main street where everything was salted and drove along towards my house. Took a turn into my street, accelerated for a bit and then went off the gas so the car would smoothly drive along with the speed slowly degrading. So I went off the gas and noticed I was a bit to the right, no wonder, centrifugal forces.

*steers left*
"Huh seems like I need a bit more"
*car still doesnt move much*
"What the- go to the left!"
*steers left hard*
"Fuck that wall is coming closer"
*Breaks*
*car doesnt break*
"FUCK FUCK FUCK FUCK!!!"

Everything got quiet in seconds, me waking up to an open airbag, ripped pants, a hurting wrist, the radio somewhere on the ground and fumes that smellt like burning wires. I grabbed my backpack that was now somewhere on the floor instead of on the seat and ran outside, tears in my eyes and the phone on my ear calling my mom. I walked inside as she walked outside, hearing a weeping scream that I haven't heard from her since I am alive. While walking inside I noticed my backpack was wet on the bottom, my 2 litre water jug shattered when my backpack hit the dashboard. I tried to stay calm and act rational, knowing that every second counts when It comes to water damage. I hastely searched for some rice and a bag to put my laptop into, stuffed the bag with both and went outside. The car was totaled, my mom pissed and crying. And I was in shock, sad, angry and hurting.

I kept the laptop on my heater for a few days, bagged in rice. I dared to try a boot after a while and you wont believe me, it fucking booted. Even the keyboard backlight worked, just the screen was obviously broken in the back (no color distortion or bad pixel rows though!!) and the aluminum shell had a dent on the front. I talked with Dell Support a few days later, asking if it would be ok to open the XPS up so I could drain all of the water. She said yes thats fine, as long as I dont touch anything or screw around with it.

She said I can send it in and get it checked, but the pickup and analysis will cost 150$ and I can go from there.

I sent it in and estimated that, because battery, screen and other things probably needed changing, it will be around 900$.

Got a call a few weeks later:

"Hello beggarboy, the repair team reported back to us and said that they will have to replace everything, which will be 1700$."

"Fuck... Buying a new one is cheaper.."

"Yeah I know I am sorry about that, I can offer you a voucher so you can buy a new one for 250$ off if you would prefer that"

"Sorry but I will need some time to consider"

"I understand."

The agent clearly noticed I was bummed about it.

After going back and forth what to do I got another call a few days later.

"Hello beggarboy, we talked a few days ago. I have good news"

"Hello, yes, speak up?"

"I was able to get a special offer for you after putting in a few words..."

The next thing she said seemed unreal to me.

She was able to cut 600$ (!!!), making the new offer 1100$, instead of 1700$ or a new one for 1500$. I figured the reason she probably did that was because I am always very polite with support members. Always.

My XPS is back and healty again.
Thank you for taking the time to read this.
Dells XPS are made of magic.

*sees that the high voltage generator kit got delivered today*
Cool, let's build this thing and integrate it into my old bugzapper! Mosquitos beware 😈

*starts building the kit, all is going very well*
Oh wow, isn't it Monday? But it's taking only 15 minutes of soldering and everything goes super smooth.. what divine power is giving me such good luck?

Alright, last thing, the transformer and then this circuit is done!!!

*solders in the transformer without realizing that the wires are coated, and the solder isn't protruding through*
Fuck. Time to desolder this shit and blast the wires with my lighter to flash that coating right off!

*engages solder pump and solder goes off extremely easily, because it only adhered to the pad*
*takes off transformer*
Me: "Nnngh..!!! Get off you piece of junk!!!"
Transformer: "Hmph!! I will stay in here no matter what!"
Me: "Get the fuck off already!!! 😡"
Transformer: *leads break off* "Alright, but these leads stay here!!!"
Me: "MotherFUCKER!!!"

Yep, it's Monday after all.

Friend of mine killed his MacBook with some Softdrink.

Just poured it all over his poor a1502.

He let it dry for a few days, it starts to work again.
Except the battery.

Goes on Amazon and buys a new battery.

New battery doesn't work either and so he tells me about it and I as stupid as I am couldn't resist the temptation to finally work on a MacBook like my "hero" Lois Rossmann does.

So turns out the board is good.
Cleaned it up and basically nothing happened to it.

So what's the deal with "los batlerias"?

The first got hit by liquid, the second had a broken connection to a cell.
That could have happened through my friend, installing it without testing it first, or at the seller, so it being a DOA battery.

Now away from the stupidity of my friend and the situation to the actual source for this rant.

Once something happens to a modern Managed battery, the Battery Management System (BMS) disconnects the voltage from the system and goes into an error state, staying there and not powering anything ever again.
For noobs, it's dead. Buy a new one.

But It can be reset, depending you know how to, and which passwords were set at the factory.
Yes, the common Texas instruments BQ20Zxx chips have default passwords, and apple seems to leav them at default.

The Usb to SMBus adaptors arrived a few days ago and I went to prod the BMS.

There is a very nice available for Windows called BE2works, that I used the demo of to go in and figure out stuff. The full version supports password cracking, the demo not.

After some time figuring out how Smart Battery Systems (SBS) "API" works, I got to actually enter the passwords into the battery to try get into manufacturer and full access mode.

Just to realise, they don't unlock the BMS.

So, to conclude, my friend bought a "new" battery that was most likely cut out of a used / dead macbook, which reports 3000mah as fully charged instead of the 6xxx mah that it should have, with 0 cycles and 0hours used.
And non default access.

This screams after those motherfuckers scaming the shit out of people on Amazon, with refurb, reset, and locked fucken batteries.

I could kill those people right now.

Last but not least,
My friend theoretically can't send it back because I opened the battery to fix the broken connection.
Though maybe, it'll get send back anyway, with some suprise in the package.

I have this little hobby project going on for a while now, and I thought it's worth sharing. Now at first blush this might seem like just another screenshot with neofetch.. but this thing has quite the story to tell. This laptop is no less than 17 years old.

So, a Compaq nx7010, a business laptop from 2004. It has had plenty of software and hardware mods alike. Let's start with the software.

It's running run-off-the-mill Debian 9, with a custom kernel. The reason why it's running that version of Debian is because of bugs in the network driver (ipw2200) in Debian 10, causing it to disconnect after a day or so. Less of an issue in Debian 9, and seemingly fixed by upgrading the kernel to a custom one. And the kernel is actually one of the things where you can save heaps of space when you do it yourself. The kernel package itself is 8.4MB for this one. The headers are 7.4MB. The stock kernels on the other hand (4.19 at downstream revisions 9, 10 and 13) took up a whole GB of space combined. That is how much I've been able to remove, even from headless systems. The stock kernels are incredibly bloated for what they are.

Other than that, most of the data storage is done through NFS over WiFi, which is actually faster than what is inside this laptop (a CF card which I will get to later).

Now let's talk hardware. And at age 17, you can imagine that it has seen quite a bit of maintenance there. The easiest mod is probably the flash mod. These old laptops use IDE for storage rather than SATA. Now the nice thing about IDE is that it actually lives on to this very day, in CF cards. The pinout is exactly the same. So you can use passive IDE-CF adapters and plug in a CF card. Easy!

The next thing I want to talk about is the battery. And um.. why that one is a bad idea to mod. Finding replacements for such old hardware.. good luck with that. So your other option is something called recelling, where you disassemble the battery and, well, replace the cells. The problem is that those battery packs are built like tanks and the disassembly will likely result in a broken battery housing (which you'll still need). Also the controllers inside those battery packs are either too smart or too stupid to play nicely with new cells. On that laptop at least, the new cells still had a perceived capacity of the old ones, while obviously the voltage on the cells themselves didn't change at all. The laptop thought the batteries were done for, despite still being chock full of juice. Then I tried to recalibrate them in the BIOS and fried the battery controller. Do not try to recell the battery, unless you have a spare already. The controllers and battery housings are complete and utter dogshit.

Next up is the display backlight. Originally this laptop used to use a CCFL backlight, which is a tiny tube that is driven at around 2000 volts. To its controller go either 7, 6, 4 or 3 wires, which are all related and I will get to. Signs of it dying are redshift, and eventually it going out until you close the lid and open it up again. The reason for it is that the voltage required to keep that CCFL "excited" rises over time, beyond what the controller can do.

So, 7-pin configuration is 2x VCC (12V), 2x enable (on or off), 1x adjust (analog brightness), and 2x ground. 6-pin gets rid of 1 enable line. Those are the configurations you'll find in CCFL. Then came LED lighting which required much less power to run. So the 4-pin configuration gets rid of a VCC and a ground line. And finally you have the 3-pin configuration which gets rid of the adjust line, and you can just short it to the enable line.

There are some other mods but I'm running out of characters. Why am I telling you all this? The reason is that this laptop doesn't feel any different to use than the ThinkPad x220 and IdeaPad Y700 I have on my desk (with 6c12t, 32G of RAM, ~1TB of SSDs and 2TB HDDs). A hefty setup compared to a very dated one, yet they feel the same. It can do web browsing, I can chat on Telegram with it, and I can do programming on it. So, if you're looking for a hobby project, maybe some kind of restrictions on your hardware to spark that creativity that makes code better, I can highly recommend it. I think I'm almost done with this project, and it was heaps of fun :D

*listens to some music over the Bluetooth headset in Groove on Windows*
*walks off to the bathroom*
> Please recharge headset
…
Which in Sony-speak means "reached cut-off voltage, you'd better recharge this fucking thing because we will power off now, rendering the warning completely useless!*
Me: "oh dear it's 5:30AM and my speakers are set to full blast"

*rushes off to the bedroom to pause Groove*
*walks back to the bathroom*

Then I started thinking, you know Microsoft.. on my phones I never had this issue since the Samsung Corby. Android has supported pausing media playback on headset disconnect for about a decade now. Maybe Microsoft Certified Enganeers could look at how the competition has solved an issue and IMPLEMENT THE FUCKING FEATURE ALREADY?!

But no, you've got that IE reputation to hold high. Sorry, I forgot.

MICROSHIT!!!!!!

I so fucking hate mosquitoes. At this point I'm seriously willing to lure all those bitches in and guide them straight to an electrical death. Problem is, I know how to generate super high voltage to char the fuckers right into smelly dust, but I don't know how to lure them in, or even find them manually, so let alone automatically. Even a chemical reaction we can electronically dispense to lure in the fuckers, but I have no idea what that chemical stuff would be. I'm not a chemist (yet). But if I can build it, fucking hell.. I would build a ton of them, weaponize my entire home and even build some spares to send off to fellow ranters. Because those parasitic bitches must DIE!! The only reason why they still exist after thousands of years is because we didn't kill the fuckers yet. I want to fucking kill the leeches, preferably in the most gruesome way possible.

So yeah. A shout for help to my fellow ranters this is.. perhaps even a collab. I have no idea about the stuff that draws those fuckers into their death. Any suggestions? Whoever can guide me to the demise of those parasitic pieces of shit, seriously.. if at all feasible, I'll build it for you and ship it!! Death to those parasitic blood-sucking bitches!!!

My first dev job was a paid internship at Oak Ridge National Laboratory. But I wasn't in the computing division with the supercomputer and the 30-foot 18-screen wall display. In a way, I was doing something more exciting. I was in the Hollifield Radioactive Ion Beam Facility.

That meant that I was working next to a radioactive ray gun that they fired at different targets to try and make new kinds of particles. To refine the beam components, there was a tower with the world's highest voltage Van de Graf generator at 25,000 kilovolts. I got training on how to put on a radiation suit, and was told that if I got locked in the wrong room and red lights began to flash, I had about five seconds to run to the far wall and push the E-stop, before I got irradiated and died slowly over the next five weeks.

But, I was reassured, that never happened. Radiation leaks are rare too (that's why we wore dosimeters). More likely, there would be a leak in the generator tower. To explain why that's bad, that tower wasn't filled with normal air. 25,000 kilovolts would punch through that like nothing, arc against the walls, and we'd lose the electric charge. No, instead, the tower was filled to a few atmospheres of pressure with sulfur hexafluoride gas. You know how helium makes your voice go up? This stuff makes your voice go down. It's heavier than air, and it kills you by displacing and starving your lungs of oxygen.

So, while I was happily coding away on PHP, CSS and the Bash shell, making a log book for all the ion gun settings and targets the scientists used in their experiments, I was keeping an ear out for the oxygen alarm. I had a blast!

When your classmates are such lobotomites, that they manage to fry 11 fucking IC's within a day! And I am the one who has to find and replace all the broken stuff. FFS it says 9V right there on the board NOT 12V! No, your board should not draw 1.7AMPS! This chip is getting kinda hot. What is wrong? ONE OF YOUR FUCKING PROBES IS BRIDGING ONE OF THE PINS!
Why isnt this working correctly? You adjusted the wrong fucking potentiometer!
I know I have far more experience than most of my classmates, but man, atleast try to not break things by just thinking: "I dont know dis. (Its actually written in the docs!) So imma assume it will be fine if I do dis. It wasnt fine!"
Also IF something doesnt work, DO NOT TURN UP THE VOLTAGE ON THE CIRCUIT BECAUSE IT APPEARS TO BE THE CLOSEST POSSIBLE ERROR. Which in most cases it is not!

TL;DR: check polarity before plugging your DIY circuits into others!!!

*goes off to watch some Lucky Star and drink some booze*
*notices phone battery dying after 3rd pint*

But my charging cable that Huawei delivered with this thing is way too short... Well that ain't no problem, I can make one of my own 😎

But I'm tipsy.. sound I really enter the workbench in this state?

*goes off to build a charging cable anyway*
But what was USB-A male connector's polarity again? Oh, there's the fan's USB connector that I've made in the past. Let's check on that one. So, left is positive and right is negative?

*solders the wires on*
Snip, strip, stick, done! Well that was easy. I guess that all those failed soldering attempts and lost pads in the past as a means of training did pay off in the end!

*plugs phone into Raspberry Pi media center through new charging cable*

Strange sounds coming from the speakers.. well that's odd. Reverse polarity or maybe the Pi can't handle a 1A load from my phone?

*plugs phone into the 5V 5A charging hub that I've made earlier*
That oughta do.. current limits should be no more in that thing.

*charging hub makes high-pitch noise similar to the Pi speakers*
Definitely a reverse polarity, isn't it :') let's check on the Gargler...
Oh shit! It is a reverse polarity mistake!!! Should've checked this earlier >_<

*resolders wires properly*
Alright, finally done.. as I'm writing this post, my phone's charging from the Raspberry Pi through my fixed charging cable now...

Lesson learned. Always check on the internet what the pinout is before soldering anything, don't solder while tipsy, and be fucking grateful that this phone has reverse polarity protection in it.

Nexus 6P with all its shortcomings regarding power delivery and battery management, luckily it's got reverse voltage protection features built-in. Otherwise it might've costed me my phone. Always double-check before plugging anything into something else!!!

I've just disassembled this LED floodlight that I bought a while ago. It's some stupid little cheapie from a dollar store, so I figured that there'd be shit inside. But I wanted that LED cob.. a power LED :3

Well, shit wasn't too far off from the truth. The component choice is reasonable, but the design of the bloody thing.. batshit insane. The LED floodlight is powered by 4 AAA batteries, connected in series. So 6VDC. That then goes into this little tactile pushbutton, into the LED cob and then a 4.7 ohm resistor.

Well that's a pretty easy circuit.. let's remove the batteries and the casement, and put it on the lab bench power supply. Probes connected to the circuit with only the resistor and the LED cob in between (I didn't want to deal with the switch). Power supply set to 6V, current limiting to 500mA, contact!! And it works, amazing! So I let it run for a while to see that nothing gets too hot.. hah. After a minute or so, smoke would come out.. LED cob was a bit warm to the touch but nothing too bad. But the resistor.. I could cook water on it if I wanted to! 100 fucking °C, and rising. What the F yo?!

So I figured that I didn't want to put the resistor in between there. Just the LED cob now, which apparently has a forward voltage somewhere between 3.2V and 3.3V depending on how I set the current (500mA and 600mA respectively). Needed a bigger heatsink though, so I jammed one of my aluminium heatsinks on there. And it worked great! Very bright too, as it takes between 1.6 and 2W of power. Just for a comparison, the lighting in my living room is 4x5W and the ones on top of my dining table are 2x3W (along with some TL bar that my landlord put there.. fluorescent I think). So yeah, 2W is quite a lot for an LED, especially when it's all concentrated into one tiny spot.

That said, back to the original design with the resistor. 2 questions I have for that moron that designed this crap. First, why use a resistor for a power LED?! They needlessly waste power, and aren't good choices for anything that consumes more than 100mA. You should use PWM for these purposes, or tune your voltage on the supply side. Second, why go with 6V when your forward voltage is 3.3 at most? Wouldn't it make more sense to use 3 batteries with 4.5V? Ah, but I know the answer to the second one. AAA cells aren't rated for high loads like this. So that's likely why the alkaline cells that I had in there before have started leaking. Thanks, certified piece of shit!

Honestly, consumer electronics are such a joke... At least there's some components that I can salvage from this crap. Mainly the LED cob, but also the resistor and the tactile pushbutton perhaps.

One last remark that I'd like to make. This floodlight was cheap garbage. But considering that you can't do it well at that price, you just shouldn't do it. You know why? Because consumers always go for the cheapest. Makes a lot of money to build at rock bottom prices and make shit, but it damages the whole industry, since now the good designs will go out of business. That's why consumer electronics is so full of crap nowadays. Some unethical profiteering gluttons saw money, and they replaced the whole assortment with nothing but garbage. I'm sure that there's a special place in hell for that kind of people.

Can’t believe I forgot to post this one:

“Science does not say you shouldn’t pee on high voltage lines, it says urine is an excellent conductor.” - Sabine Hossenfelder

Connecting 5v on 3.3v device. Holly smooooooke.

South Africa Electricity:

This is after I lost my 7th 3000VA online UPS...

In South Africa we have 240V power most of the time which is great, but then there is scheduled power outages (because our electricity companies cannot "handle the load").

When we have a power outage we have automatic generators which brings everything back up although there is still the 1 minute drop which has weird spikes and odd voltages before switching to the generator (as the generators wait until they are stable)

This has being destroying our equipment, we had a $2000 repair bill 3 TIMES for 3 SEPERATE Xerox Machines that have surge protectors although their circuit board somehow fried.

We have lost 7 3000VA UPSes (3 different brands) and 5 voltage regulators we put to protect the UPSes.

The one UPS that fried just had 2 dead fuses, I decided to replace them (unplugged the batteries to avoid 240V) and when plugging the batteries back in there was a huge spark and flame and the metal and plastic melted onto the board and turned black (the metal pins to connect the battery are non existant now)

I am done with electricity...

P.S. 2 of our generators also got hit by lightning as we are high on a hill and ALL the plastic cable coverings inside the generator were melted

*receives an old business laptop as payment for refurbishing another one*

Hmm, this thing doesn't have a charger with it.. looks like it's taking 18.5V.. my HP laptop's charger supplies that but its barrel connector doesn't fit 🤔

Regular users: oh dear now I have to buy a charger with a fitting connector for this.. where do I even start?!
Me: Well I guess I could just remove the charging port and solder some wires straight into the board instead 🤔

But that voltage.. my HP laptop's charger is still in use and I don't really want to fuck around with that one.

Regular users: oh dear oh dear, shouldn't I just throw this laptop away?
Me: well I guess that I could just use one of the rails of my upgraded lab bench power supply for it?

Lab electronics saving the day, every day, time and time again.. fuck yeah 😎

2 days ago: *rants about HP's design choices on a laptop*
22 hours ago: *new video from GreatScott comes out, explaining all about voltage tolerances for the charger etc*

Coincidence? Maybe not 🤔

Finally, the jeezless present is done.. fuck this shit, where's my booze and my bed?! 😒

Anyway, it's essentially a power bank with LED's attached to it. The LED matrix is at the back side and looks reasonably decent (but I don't wanna disclose the age it's displaying). It's powered through a 47ohm resistor and is directly attached to the 5V lines. Yellow LED's with 2V voltage drop that have each number completely parallelized, and then those numbers are put in series to increase the combined forward voltage of the LED's to 4V. That way the circuit is around 80% efficient (resistor drops 1V, LED's drop the remaining 4V). Other than that, nothing too special. It did take 2 nights to build though.. way too much for a mere formality 😑

iPhones are ridiculously picky when it comes to finding a mate- um charger. And knowing why doesn't really make it any easier to understand why. If anything it baffles me more.

So, let's start with appliances that are not phones. Think Bluetooth headsets, keyboards, earbuds, whatever. Those are simple devices. They see 5V on the VCC line and 0V on ground, and they will charge at whatever current they are meant to. Usually it will not exceed 200mA, and the USB 2.0 spec allows for up to 500mA from any USB outlet. So that's perfectly reasonable to be done without any fuss whatsoever.

Phones on the other hand are smarter.. some might say too smart for their own good. In this case I will only cover Android phones, because while they are smarter than they perhaps should be, they are still reasonable.

So if you connect an Android phone to the same 5V VCC and 0V ground, while leaving the data lines floating, the phone will charge at 500mA. This is exactly to be within USB 2.0 spec, as mentioned earlier. Without the data lines, the phone has no way to tell whether it *can* pull more, without *actually* trying to pull more (potentially frying a charger that's not rated for it). Now in an Android phone you can tell it to pull more, in a fairly straightforward way. You just short the data lines together, and the phone will recognize this as a simple charger that it can pull 1A from. Note that shorting data lines is not a bad thing, we do it all the time. It is just another term for making a connection between 2 points. Android does this right. Also note that shorted data lines cannot be used to send data. They are inherently pulled to the same voltage level, probably 0V but not sure.

And then the iPhones come in, Thinking Different. The iPhones require you to pull the data lines to some very specific voltage levels. And of course it's terribly documented because iSheep just trying to use their Apple original white nugget charger overseas and shit like that. I do not know which voltage levels they are (please let me know!), but it is certainly not a regular short. Now you connect the iPhone to, say, a laptop or something to charge. An Android phone would just charge while keeping data transmission disabled (because they can be left floating or shorted). This is for security reasons mostly, preventing e.g. a malicious computer from messing with it. An iPhone needs to be unlocked to just charge the damn thing. I'm fairly sure that that's because the data lines need to be pulled up, which could in theory enable a malicious computer to still get some information in or out of it. USB data transmission works at at least 200mV difference between the data lines. It could be more than that. So you need to unlock it.

Apple, how about you just short your goddamn data lines too like everyone else? And while you're at it, get rid of this Lightning connector. I get it, micro USB was too hard for your users. I guess they are blind pigs after all. But USB-C solved all of that and more. The only difference I can think of is that the Lightning connector can be a single board with pads on either side on the connector, while in USB-C that could be at the socket end (socket being less common to be replaced). And at the end of the day, that really doesn't matter with all the other things that will break first.

Think Different. Think Retarded. Such tiny batteries and you can't even fucking charge them properly.

I haven't ranted for today, but I figured that I'd post a summary.
A public diary of sorts.. devRant is amazing, it even allows me to post the stuff that I'd otherwise put on a piece of paper and probably discard over time. And with keyboard support at that <3

Today has been a productive day for me. Laptop got restored with a "pacman -Syu" over a Bluetooth mobile data tethering from my phone, said phone got upgraded to an unofficial Android 9 (Pie) thanks to a comment from @undef, etc.

I've also made myself a reliable USB extension cord to be able to extend the 20-30cm USB-A male to USB-C male cord that Huawei delivered with my Nexus 6P. The USB-C to USB-C cord that allows for fast charging is unreliable.. ordered some USB-C plugs for that, in order to make some high power wire with that when they arrive.

So that plug I've made.. USB-A male to USB-A female, in which my short USB-C to USB-A wire can plug in. It's a 1M wire, with 18AWG wire for its power lines and 28AWG wires for its data lines. The 18AWG power lines can carry up to 10A of current, while the 28AWG lines can carry up to 1A. All wires were made into 1M pieces. These resulted in a very low impedance path for all of them, my multimeter measured no more than 200 milliohms across them, though I'll have to verify and finetune that on my oscilloscope with 4-wire measurement.

So the wire was good. Easy too, I just had to look up the pinout and replicate that on the male part.

That's where the rant part comes in.. in fact I've got quite uncomfortable with sentences that don't include at least one swear word at this point. All hail to devRant for allowing me to put them out there without guilt.. it changed my very mind <3

Microshaft WanBLowS.

I've tried to plug my DIY extension cord into it, and plugged my phone and some USB stick into it of which I've completely forgot the filesystem. Windows certainly doesn't support it.. turns out that it was LUKS. More about that later.

Windows returned that it didn't support either of them, due to "malfunctioning at the USB device". So I went ahead and plugged in my phone directly.. works without a problem. Then I went ahead and troubleshooted the wire I've just made with a multimeter, to check for shorts.. none at all.

At that point I suspected that WanBLowS was the issue, so I booted up my (at the time) problematic Arch laptop and did the exact same thing there, testing that USB stick and my phone there by plugging it through the extension wire. Shit just worked like that. The USB stick was a LUKS medium and apparently a clone of my SanDisk rootfs that I'm storing my Arch Linux on my laptop at at the time.. an unfinished migration project (SanDisk is unstable, my other DM sticks are quite stable). The USB stick consumed about 20mA so no big deal for any USB controller. The phone consumed about 500mA (which is standard USB 2.0 so no surprise) and worked fine as well.. although the HP laptop dropped the voltage to ~4.8V like that, unlike 5.1V which is nominal for USB. Still worked without a problem.

So clearly Windows is the problem here, and this provides me one more reason to hate that piece of shit OS. Windows lovers may say that it's an issue with my particular hardware, which maybe it is. I've done the Windows plugging solely through a USB 3.0 hub, which was plugged into a USB 3.0 port on the host. Now USB 3.0 is supposed to be able to carry up to 1A rather than 500mA, so I expect all the components in there to be beefier. I've also tested the hub as part of a review, and it can carry about 1A no problem, although it seems like its supply lines aren't shorted to VCC on the host, like a sensible hub would. Instead I suspect that it's going through the hub's controller.

Regardless, this is clearly a bad design. One of the USB data lines is biased to ~3.3V if memory serves me right, while the other is biased to 300mV. The latter could impose a problem.. but again, the current path was of a very low impedance of 200milliohms at most. Meanwhile the direct connection that omits the ~200ohm extension wire worked just fine. Even 300mV wouldn't degrade significantly over such a resistance. So this is most likely a Windows problem.

That aside, the extension cord works fine in Linux. So I've used that as a charging connection while upgrading my Arch laptop (which as you may know has internet issues at the time) over Bluetooth, through a shared BNEP connection (Bluetooth tethering) from my phone. Mobile data since I didn't set up my WiFi in this new Pie ROM yet. Worked fine, fixed my WiFi. Currently it's back in my network as my fully-fledged development host. So that way I'll be able to work again on @Floydian's LinkHub repository. My laptop's the only one who currently holds the private key for signing commits for git$(rm -rf ~/*)@nixmagic.com, hence why my development has been impeded. My tablet doesn't have them. Guess I'll commit somewhere tomorrow.

(looks like my rant is too long, continue in comments)

26 or so hours up now. And I've got a few stories to tell :) feel free to refresh your cup of coffee and take a seat.

Last few days I've been going into this odd place called intown.irl to get in touch with its inhabitants. An odd place I have to say. But in some cases quite rewarding, even got a MILF home with me and into bed at some point. Anyway...

3 days ago I think it is now? Thursday evening I took my laptop to this local bar where I had this issue about dihydrogen monoxide with one of the bartenders earlier (you'll find that rant on those keywords). Still wanted to visit it regardless though, as I met that first woman there earlier that approached me. Unfortunately I didn't see her there that day.

Some bald guy who was clearly drunk approached me. Many people were already giving curious looks at this laptop I brought to the bar. I finally tuned it up with the stickers from FOSDEM.. I'll put a picture of it in the comments. My theme was one of privacy (central), distributions and Google's open source initiative (which aligns with the keychain token I got from them as well). But of course.. that guy.. he thought that a pimped/riced laptop obviously meant that I was a hacker.

Guy went to the toilet.. went back.. and suddenly grabbed my laptop and turned it towards him. Boy was I never more smugly satisfied that those rubber pads on the bottom are quite resilient. Could've almost damaged my screen by trying to grab it like that. But it's a CCFL display.. so high voltage. If it were to become broken.. worth it. 😈

On it at the time was a terminal, pinging Google (had network issues at that bar, to the point where one of the - I think - staff members got up to me and offered the WiFi password and got to talk with me.. more on that later), and my usual Linux desktop along with the Arch anime wallpaper with the quote of Da Vinci.. simplicity is the ultimate sophistication. Of course the guy saw the terminal.. and probably reaffirmed.. yep, that's a hacker. At least he wasn't too wrong about the general term.. but the hat.. most likely he was wrong on that one.

Guy left with this question.. "you are a hacker, aren't you."
I replied to him: "No sir. I'm not a hacker. I've got no idea what you're talking about."
Guy kept looking at me weirdly for the whole night to come.

Back to that companion guy though. Mac user, yada yada.. but he told me about his backup solution. Apparently - I shit you not - he has not only the photos on his local device, he's also frequently backing them up in Time Machine (which I was really curious about whether it uses mirroring or snapshots.. he couldn't tell, lmk if you do) but not only that.. he was storing another offsite backup in that very bar, in case his house went on fire.

Now that is a proper backup scheme!!! If only more people were like that.

Seriously though.. that bald guy who took my laptop just like that... I just let it slide for that one time, but I tend to treat my machines as an extension of my very self. I think that was a very uncalled for move. Asshole...

How would you have reacted to such a thing? And.. maybe that's why we technologists don't get outside too often? Fucking everything is hacking these days if it's not Knopkes and Blinkenlights… Not every shell is a h4xx0ring console for h3kk1ng de fasbuk…

God, the iPhone 11 pro's triple cameras ARE SO UGLY. OnePlus 7 has three back cameras and it's not ugly, so it can be done! It's just so, so fucking ugly. It looks like where you might plug in a high voltage power cable or something. And of course it still has a notch. That's two design failures in one expensive phone. No thanks!

(From owner of iPad Pro - not an Apple hater!)

Got my first soldering project working. Looks trash and horribly done but it does power the RPI from my 3d printers power supply using a buck converter to drop the voltage

Thankfully I got 2 pack of the usb c breakout boards. The first attempt is horribly mangled 😅😅😅 did i mention i suck. Lol

Hey guys.
Got this motor here... What do you think it's voltage is?
Tryed 12v, didn't even move...

!rant ✓devrant-meetup

Met @condor irl today. He's the same weird guy as I feel at moments. Interests that don't interest people around us in any way..

Drank some beers, evidently called Belgium.
He came all the way to the town I work at.. kudos!

Talked about breadboards taking 230V via cables that aren't meant to take the voltage in any way.. Security implications in networks and online services, like Fb. Faraday's cage & how it works; and some other shit I swear I won't tell anyone about as you should be comfortable discussing it.

Quite interesting, I swear! (:

Now on the bus home, as I had to cut it short to get to some parental business... But I'm looking back on some positive social interaction, which I'll gladly re-do another time.

Condor, it was sure nice to meet ya. I'll come your way next time. That ~10eu for your transport will be equalled some day in the near future.

@FunkDelegate sorry it was badly timed and plaved, you'll join us soon enough! At least you saw decent ass! xD

So last week I got my second 3D printer. I have done a few prints with it and this weekend I wanted to connect it to an Octoprint instance on my Raspberry Pi. Yesterday everything went great, got some plugins installed, changed all settings within octopi, connected it to my network and this morning I thought let's connect it to my printer and try to print something with it. But everytime I executed my gcode it gave an error about the heated bed not being able to heat up. Even though I did see all communication between the printer and octopi, on both ends.
I've disassembled the build plate to see what could be causing the heating issue. Did not see anything. Strange...

I assembled the whole thing again and then turned on the printer and tried printing again. Hmm, now it does work, why? Me thinking a bit and then realizing that before I didn't hit the power switch on the printer and apparently the Pi gave enough power through USB to turn on the display and do basic logic like doing beeps on touches and changing variables on the screen. The worst thing is that octoprint gave me warnings about low voltage on the Pi even though I was using the official Raspberry Pi power adapter...

A few days after the vacation, daddy (me) finally finished copying all the photos from the digital camera to the big external hard drive. Left it lying in the living room, in the corner where all the tech stuff frequently lies. In come my boys, and I'm not sure why, they start plugging power supplies around. Unfortunately the one from the laptop fit into the hole on the external disk, but had a different (higher) voltage. Result: 1 fried hard drive, containing all the baby photos and videos of said boys up that time.
I still believe that it's only the circuit board that is fried, and the data is still all there. I still have the hope to find a used disk, replace the board and all will be back.

Trying to install python3.7 for one fucking dynamic library for the past 3 hours. Built from multiple 3.7.x sources, tried altinstall, enable-shared, install, with/without optimizations, tried virtualenv which is absolutely fucking irrelevant but I tried.
Now I'm just asking someone who has it to send me the worthless soup of voltage fluctuations

oh and fuck python. or people that use it irresponsibly. im not in the right mind to distinguish

Our profs: you are CSE students, you must be familiar with Linux
Their Linux: Ubuntu 20.04 LTS
Their tools: working for them

The default USB voltage hould have been specified to 6 instead of 5 volts.

Six (6) volts would allow for longer cables than five (5) volts do, since the spare voltage compensates for the resistance of cables. This is even more crucial for USB hubs. USB hubs are highly dependable upon these days due to laptop vendors dropping the number of USB ports down to two or even one. I am looking at you, Medion.

If several devices are connected to a USB hub, the voltage can quickly drop below 4.5 volts due to the resistance between the USB hub ports and the computer's USB port, causing some devices to restart themselves even if the computer's USB port is not over capacity. If it were over capacity, it would just regulate down its output voltage to prevent overcurrent.

Lithium-ion batteries need at least 4.3 volts arriving at the battery terminals to fully charge, and mobile devices are typically not equipped with a boost converter. Even if they were, they are rather inefficient, meaning they would produce significant heat and waste a power bank's energy. Other USB devices such as flash drives and peripherals might power off below 4.5 volts. However, 6 volts have solid 1.7 volts of margin to 4.3 volts, more than twice the margin of 0.7 volts that 5 volts have. On the way from the power supply to the end device, the voltage has to pass several barriers which weaken it, including the cable, connector endings, and the end device's internals such as the charging controller.

Sure, there are quick charging standards such as by Qualcomm and MediaTek which support elevating voltages to nine (9), twelve (12), and even twenty (20) volts. However, they require support by both the charger and mobile device. If six (6) volts were the default USB voltage, all devices would have been designed to accept this voltage, and longer cables could have been used anywhere. Obviously, all USB devices should be able to run on five volts as well.

Six volts would have been more stable, flexible, and reliable.

Not sure if a rant but.

How many of you guys gets so bored durning meetings on all the none important stuff or not related to you that you just start codeing instead?

I have these hours long meetings with analist that can talk calculations all dat long, how usefull they are, wich analyses you can do for them. I really don't care. Just tell me the formula and I will make it. Do not care whether A is voltage or the amount of pink clouds on sunday.

Hey Guys
Safety Question.
If I charge a 220v capacitor with 5v... Does it accumulate up to 220v or just the voltage I give it? Thanks

I am trying to reverse engineer a fingernail hardening device for rapid hardware prototyping (becoming some kind of hardware developer I guess)

Since it is a fucking mess (all cables are black) they've chosen a weird construct to operate microcontroller on 240Vac (seems to be possible and made in very low energy consuming devices) i do not find any datasheet for one of the used products. It would help a lot but no. And messing around with high voltage is no fun.

I'm unsure if this fits as a dev rant since most/all I've read so far are software-related.

I told you guys that I would update you on my PiBM-5150 project. I figured out the hard way that my USB to DB-25 cable wouldn't cut it. Seems it is for printers and no matter how hard I tried it wouldn't work because of the path of the wires. After researching, it is apparent that the GPIO pins on the pi are configured for serial by default but it requires a little voltage change from TTY to RS-232. Rather than do like one of the videos I saw and solder junk to a bread board, I found a serial (rs-232) shield and 9pin output for the pi. Now, both computers are true rs-232 each. Instead of using a modem between them, I bought a null modem cable (crossover of Tx Rx signals) to interface the two machines directly. I'll update this evening to show it hopefully working.

E-mail returned to sender, insufficient voltage. 🤔

I just wanted to develop a cool webapp-controlled lighting for my bar.

Next things I know, there is electronics scattered everywhere, 2 multimeters to find what the fck is wrong with a PSU not outputting 1/100 of the current it's supposed to, said PSU opened on my desk, and I'm trying to find a capacitor online because there isn't any fcking electronics store selling spare parts anymore in my city.

Context:
- PSU means Power Supply Unit, in this case a computer one.
- PSU was given by a friend and is out of warranty
- the total consumption for all LEDs is 24A @ 5V consumption. A refurbished PSU is ideal for that
- that PSU is rated 2A @ 5V on the stand-by, which is perfect to power a Raspberry Pi. The issue is that there is a sharp voltage drop as soon as you try to use more than 20mA.

Had Arduino for months, couldn't get MPU6050 working, because of a lack of time and other stuff. (Need it for long term college project, data logging blah blah)
Gave it to project teammate to figure it out, who hates even touching hardware, BTW.

He figures it out in an hour (adjusting baud rate for supply voltage)
I feel like a complete idiot.
🙁

Task: blinking light.

Boomers: One lightbulb, one bimetallic strip.

Zoomers: LED (D13), Atmega328P, Atmega328, 5V, 16MHz, 2KB SRAM, 32KB flash, 1KB EEPROM, FT232RL, 19.0mm x 43.18mm, 16 analog pins, 14 digital I/O pins, 6 PWM pins, 2 resettable fuses, 8MHz external crystal, 16MHz external crystal, 12MHz crystal, 0.5mm pitch, 0.1 inch headers, 1.27mm pitch headers, mini-USB, 3.3V regulator, 5V regulator, 16MHz ceramic resonator, 1N5819 Schottky diode, 47uF capacitor, 100uF capacitor, 10uF capacitor, 100nF capacitor, 0.1uF capacitor, 22pF capacitor, 1N4007 diode, 10K resistor, 4.7K resistor, 330 ohm resistor, 10uH inductor, 27 ohm resistor, 2x3 ICSP header, reset button, LED (D13), green LED, red LED, yellow LED, 6-pin header, 8-pin header, 28-pin DIP socket, 6-pin FTDI header, ceramic resonator, USB mini-B socket, 16MHz oscillator, M7 diode, LDO voltage regulator, 3.3V regulator, 5V voltage regulator, polyfuse, 22pF capacitors, 100nF capacitors, 10uF capacitors, 47uF capacitors, 100uF capacitors, 1N4007 diode, 1N5819 Schottky diode, 16MHz resonator, 0.1uF capacitor, 330 ohm resistors, 27 ohm resistors, 4.7K resistor, 10K resistor, 10uH inductor, 22pF capacitor, mini-USB connector, 8-pin header, 6-pin header, 2x3 ICSP header, reset button, ceramic resonator.

so, any EE here?
I'm a self-taught EE (shots fired! I was told to call myself an "inventor" so I don't offend my dear EE friends!)

Anyways... I just made a huge insight that wanted to share!

in the circuit that has been breaking my head for the past couple of days (switching DC-DC [boost, buck] converter the inductor takes care of holding the current stable while the capacitor the voltage. (apart from an low-pass filter...) The higher the frequency the smaller the capacity of the inductor needed, the less amount of wire, less resistance, more watts!!!!!

Fucking pt100 sensors and fucking max31865 amplifiers! Waited a few months to arrive (working on an arduino bbq temp monitor and log server), ordered fucking everything, asembled fucking everything and this piece of fucking shit reads random values between -200 AND 980 DEGREE not even constant and sometimes gives under/over voltage. Tried a whole another max and different pt100s but every fucking time this random madness. WHY THE FUCK IT CANT JUST DISPLAY THE FUCKING TEMPERATURE???

Any recommendations for introductory books on electrical engineering? I'm looking for something that goes into detail on the basics: tension, current, resistance, inductance, capacitance, etc. I have very little knowledge on the subject (I know what the basic components do and that's it) and I found myself struggling a bit with the most basic concept: voltage.

I grabbed my multimeter, a few resistors and a battery and played around a bit. For some reason it doesn't really "click" why on a 5v circuit with 3 2.2k ohm resistors (I think) the voltage around each resistor was like ~1.3 volts or something, while on a circuit with 2 resistors the voltage accross each one was ~2.3 something volts (I don't remember exact values). Like, I know that voltage is a difference in potential, but I still don't get it and idk what I'm missing. Why is the difference in potential accross a resistor different if the circuit has 2 resistors in series instead of 3. It kinda makes sense in my head but at the same time it doesn't.

In short, I want to know the "why" stuff works the way it does, not just the "how".

Also, if the book covers common practices, components, and circuits that'd be very helpful. I want to learn how to build well-designed, reliable and safe circuits.

Was in a university group project and had to make an angular momentum measurement device. An hour before demo voltage on one of the pins was still a bit too high. Friend drove to Chinatown not too far away from campus and bought a pack of the cheapest batteries. Plugged the cheap batteries in, the voltage was just spot on. How awesome was that!

I don't know why you expect your website to be done in a month when you can't even fucking decide what it should be.

I CAN'T READ YOUR MIND ASSHOLE.

Don't tell me that I did it wrong or it doesn't look right when you said that you wanted it like that.

I wasn't hired as a web developer, I've done high voltage electrical work, machinist work and repair of the shit you can't even take care of. All for 15usd a hour. If they don't keep their promise to bump the pay....

[Question]
What type of amplifier circuit would I need to power a 60w 8ohm speaker or can you recommend any prebuilt amplifier boards ?

[TLDR;]
I spotted the below stuff while cleaning out my junk cupboard and thought it might be a fun side project to convert them into a portable bluetooth speaker since the earphones are shit anyway and I've always wanted to learn more about amplifiers.

The only question remaining is how to amplify the headphone output signal enough to power the speaker. I plan on either using cells from old laptop batteries or a motorbike battery as a power supply so input voltage would be roughly 10-12v.

The speaker is from a set I salvaged from an old 80's hifi and has excellent sound quality, would mounting the components inside it have a large negative effect on it's sound?

Also although I would prefer to make my own amplifier board as a learning experience the goal is to have a portable speaker with good sound quality... is this something I'm likely to get from my first attempt at an amplifier or should I rather get a ready made board?

Question for the electrically minded.

I have a laptop with a 19v input.

I have a portable UPC with 2 voltage options in the range of this, I can undervolt at 16v (the laptop battery voltage) which works with a small firmware correction to ignore a board sensor, the other option is to slightly overvolt to 19.5v which I assume the laptop could handle through its input regulation.

Can anyone confirm if a .5v variance at charger is within tolerance? It would be an overvolt of 2.5%

I now understand why my Pixel 2 can't take photos...

The problem isn't the camera but the battery... Somehow the battery can't supply extra load (voltage/current?) that the camera needs...

Alright. Got a new adapter (note: my laptop charger has a US prong and I have the European standards but it still tolerates 220V).

it appears that the tiny arcs that were made turned into HUGE sparks because the electricity went to the adapter and because the US prongs were exposed (bc my adapter was bullshit) then I got DOUBLE the voltage running into 1 charger (1 time for the adapter and 1 time for the normal exposed US prongs) so the breakers popped.

(this is my theory don't bully me for being inaccurate lool)

Prof ranting about me cause I asked why he had an increase of 3.5dB when doubling voltage on his ppt. Told me I should have searched online to get why it is 3.5dB
YOU FUCKING RETARD IT IS 3.01 AND YOU CAN CALCULATE THAT

Probably one of these:
- electrician (middle or low voltage)
- unfit for employment in germany, which is the worst.

I have this fixation with minmaxing core clocks, voltages and their respective curves (P states, basically). I'm still not sure how much it actually improves my experience, but I'll be damned if it isn't fun and interesting to mess around with these numbers and see them climb higher but remain stable.

Currently messing around with a Vega 64. They come in severely overvolted, and I'm trying to get it to retain its performance with less voltage aka less heat. I don't even need to turn on central heating if I'm running stress tests, the bloody thing runs at 80°C! So I guess you can see why undervolting the card is of interest

Thank God for "Screen" my remote Linux build session is alive in spite of fucking network outages! I'm telling you, when your company doesn't have voltage regulators, network goes down everytime there's an electrical fluctuation!

Does anyone familiar with overclocking Ryzen non-x cpu? I had a Ryzen 7 2700 with gigabyte B450 motherboard. The core voltage locks to 0.9v after clock ratio set to 34 from auto (3.2GHz). But on auto, the vcore is around 1.38v, which is close to max recommendation. Why?