However this is not a lithium polymer battery, and as it’s a 32700, it is not a prismatic or pouch cell either. It is a lithium iron phosphate (LiFePO4) cylindrical battery in metal housing. Battery University does have them listed in their table of chemistries (in case you’re curious), but they don’t seem to have much detailed information. Enough to build a charger though :)
Anyway, thanks for your reference in any case! I’m not responding to criticize you, only to improve the utility of this conversation in case someone else finds it on search :)
Hello y’all! I’ve always been interested in computers and programming for as long as i can remember, but recently i’ve decided to try to get into some of the deeper stuff behind that, into the wonderful world of electronics. Where should I start? What courses or books or youtube series should I consume? What are some...
The most important thing is to tackle projects frequently and get yourself involved with other people doing the same. Learn by doing! I found books, videos, and so on of limited utility by comparison. I’ll include an unreasonable quantity of my notes below.
Some useful resources:
Learning Python – a decent programming language to start with since it’s flexible and enforces some good habits : python.swaroopch.com
Websites with details on other people’s cool projects: hackaday.com
You should also learn C / C++ (unless you are an assembly-language degenerate like me)
KiCAD is fantastic these days (and free!): www.kicad.org
I’ll point out that Microchip Studio is awful and buggy but for some microcontrollers you’re stuck with it. Everyone working with embedded systems gets stuck with some lousy manufacturer-supplied software sometimes.
List of initial things to learn:
How to read component datasheets (you will be doing this a lot). Actually I think a lot of my electronics knowledge was picked up from just absorbing datasheets like a weird sponge of some sort.
How to order from Mouser / Digikey / RS Components / Arrow / McMaster (these are also a great source of datasheets)
Basic laws of electricity and magnetism (any freshman university physics textbook is OK – these pop up used all the time, and even an old one is OK). Just do all the problems in each chapter and you’ll be fine. Or you can tackle “The Art of Electronics” if you like.
Soldering is actually pretty easy, just buy some resistors and some prototyping board and get some practice in. You’ll need to learn surface mount soldering to get access to good and cheap parts later on, but thankfully, it is way easier than it looks. Like, really a lot easier than people make it look.
How to order manufactured circuit boards from a factory using a design in KiCAD (this is actually pretty easy and cheap!)
These days, a lot of components can be purchased on pre-built ‘modules’ that fufill a certain objective. For example, a temperator sensing module might have a sensor and all the supporting components on a little board, so you just connect power+ground and data. These are made specifically with learning in mind and are made in Asia at a very reasonable price – do note though that reading the actual datasheet of the parts in question will give you much deeper knowledge over time.
Tools to buy:
A soldering station. Some people suggest fancy expensive stuff, but frankly, some brands of Chinese tools have gotten quite good. Yihua is a good and affordable brand of soldering station. You can get a soldering-iron-only version if you need to save money, but I’d recommend a model that also includes a hot air rework tool. This makes fixing mistakes on boards way easier, lets you salvage components more easily from junk and failed projects, and also adds a lot of flexibility later on.
A multimeter / parts tester. Should measure voltage, current, capacitance, resistance and diodes. Pro’s Kit is an OK brand from Asia.
Eventually you will need an oscilloscope, but not at the start. Hantek, Rigol, and Unit-T make good entry level ones. Siglent is midrange. Tektronix is for rich kids. An old used scope is fine but often shipping is expensive if it’s one of the heavy ones.
Tweezers, wire cutters and strippers. Lots of protoboard and solder.
If you’re really into low-level microcontroller stuff, an AVR-ICE will be pretty cool to have a few years down the line :)
Platforms and Communities to Consider:
Arduino – largest friendliest community with the most tutorials, but as such has a ton of beginners and students looking to copy/paste code without understanding. So sometimes it’s hard to find someone knowledgeable, and if you do, they might be sort of exhausted. It’s probably the best place to start these days overall.
AVR Freaks – the opposite of Arduino. Hostile, but super knowledgeable. I’ve learned so much by searching their forums, I’ve never needed to ask a question! They are great too, but really not a place for beginners to ask questions. It is a good forum to read if you want to learn assembly / C for microcontrollers, but has a steep learning curve – I’d save it for later :D
Raspberry Pi – makes everything super easy, generally at the cost of being horribly inefficient and somewhat expensive. It can be a good place to start, but be careful not to learn bad habits here – e.g. using a whole computer system with Linux to blink an LED. You’ll end up having to unlearn a lot to make reasonable battery-powered devices later on. Awesome where processing power is actually needed – machine vision, some robotics, and AI. The raspberry Pi Pico has fewer of these problems (and you can code in Python!) – it’s pretty fantastic and I would personally choose it as my first microcontroller.
Other Stuff:
Avoid playing with mains power / high voltage until you know what you are doing.
Avoid selling things until you know what FCC / CE is. You can teach courses on what you’ve learned to fund your studies though! I bootstrapped this way.
Lithium batteries can be sort of tricky / hazardous. When starting out with them, use the metal cylindrical cells at first. The TP4056 is an OK charge controller to use, and pre-built modules are like a dollar in bulk.
I own a prototyping company in Asia, this introduces some bias on my tool recommendations: low cost, high value – but only ‘good enough’ performance and convenience. I also hate solderless breadboards and consider them more trouble than they are worth – some people disagree with me and they are also correct. I also find surface-mount soldering way easier and more reliable than through-hole (most people disagree with me but it’s worth thinking about). Finally, I’m a 700 year old Taoist immortal that still uses a slide rule and writes poetry in Assembly language. So I’m part of an older engineering tradition and it’s worth keeping that in mind when weighing my advice.
Disclaimer: this is not specifically for a commercial product, but various things I design sometimes get commercialized. I mention this so that you may decide whether you want to weigh in. If it’s commercialized, I will probably make very little money but a bunch of university students may get a neat STEM program in the...
Hello! What would be a good way to learn about electronics in terms of creating them? I’m particularly interested in building my own keyboards and other PC peripherals, but I’m not sure what tools I would need, or what’s a good knowledge base if I run into any issues. Any tips and or suggestions?
Well, you could say that there are three branches of electronics: analog, digital, and discrete (sort of between the previous two). For your goals, you mainly need to learn about digital systems.
What you’ll mainly be dealing with in terms of digital systems are microcontrollers and other embedded systems. I’d say the main two places to get started with those are the Arduino and Raspberry Pi ecosystems. The first is “more pure microcontroller” and the second is “more advanced embedded systems”.
Microcontrollers are mostly programmed in C++ these days (with a few strange people like me using Assembly), and the Arduino ecosystem sort of teaches that. Microcontrollers are usually the most efficient system to make the control electronics for something like a keyboard. Sparkfun and Adafruit are good companies to buy parts to get started from.
Embedded systems like the Raspberry Pi stuff can often run a whole operating system. This is too expensive (power, space, and $) for most keyboard builds, but you may want to learn how to use them for other projects. However, they also make a microcontroller (the Pi Pico) which would be OK and can be programmed in Python.
For advanced computer peripherals, you might need to learn FPGAs. However, that can be a difficult topic to get into by comparison. So maybe leave that for later.
A good way to get started is to buy the parts for, and build, a few Arduino projects. There are specific libraries for making Arduinos emulate a PC keyboard too.
In terms of tools, at first you will just need a breadboard, some resistors, LEDs and jumper wires. Maybe a battery or USB power supply. A multimeter too.
Soon after you will probably want to learn to solder to start making your own standalone devices. You should get a soldering station with temperature control – some people swear by Hakko, myself I have a cheap-but-good Yihua soldering + hot air rework station.
Next, while Sparkfun and Adafruit are great businesses, they are not cost-effective ways to source a lot of parts. You’ll want to learn how to use the part search and ordering functions on Digikey, Mouser, Arrow, and RS Components. Maybe also McMaster-Carr if you do mechanical stuff.
When you have some working designs done, you will probably want to learn KiCAD. It’s software for designing circuits, and laying out printed circuit boards (PCBs) to send to a factory to be made professionally. Through the magic of globalization, this is actually pretty affordable! A typical run costs me 20-40$ for 10 units, and takes 16 business days – although I live in Asia, so it might cost a little more from the USA or Europe.
You’ll also maybe want to learn 3D modelling and printing, for designing cases (I struggle with this more than I’d like to admit). TinkerCAD is an OK place to get started, although tools like SolidWorks are certainly more advanced. You don’t need to buy a 3D printer unless you want to – you can just order your designs made online.
Anyway, the results with KiCAD + 3D printing can be really quite good and can last many years of use. They also let you share your design with others, so other people can make it!
Finally, if there’s a hackerspace / makerspace in your area, these are great communities of people you can learn from. Definitely check them out. They may have a 3D printer you can use, as well as other tools. Often they teach courses too.
One small note – getting from “hey neat this works!” to making and selling a product is (sadly) a really big step. So if you one day want to do that, build a network and ask for advice from someone who has gone through it first.
Serious question from a beginner in electronics. For reasons I do not fully understand, I have become fixated on the idea of collecting small amounts of electricity from “interesting” sources. I don’t mean “free energy”, instead, I mean things like extracting a few mV from being so close to a AM radio tower using two...
It’s a fun engineering challenge. Weird energy harvesting tech mostly has applications for sensor networks. Some of the new generation of bluetooth chips have ridiculously low power consumption – so being able to deploy them without a battery somewhere without maintenance is occasionally useful.
Some currently used technology are piezo energy harvesting from mechanical vibration, low-light solar, and thermocouples.
My approach is usually to think around the TPL5110 and a pseudocapacitor. The TPL5110 is a timer that has a current consumption of 35 nA and can operate down to 1.8V. Every 2 hours, it would activate an ATtiny10 that can operate in the microampere range. That chip (very quickly) measures the voltage on the capacitor relative to a reference and decides whether it has enough power to “do the thing”. If it does not, it signals to the TPL5110 to turn itself off for another 2 hours to let more charge build up.
If it does have enough power, the ATTiny10 either “does the thing” itself or switches a MOSFET to activate another system or whatever. The “thing” can be to use the power stored in the pseudocapacitor to charge a battery for a short time (e.g. around a second), if you want. Afterward, the system goes back to sleep until it has a relevant amount of power again. However it’s often a battle to outpace the self-discharge of a lithium cell, so having the system “do a thing” without a battery present is often better.
This does result in practical stuff sometimes, especially when using low-light solar. Besides sensor networks, you can for example manufacture replacements for tritium indicator lights this way that only activate on at night. In my experience, an SMT indicator LED is quite visible at night with under 10 uA of current. I have a series of ridiculously overengineered indicator lights that stick to the top of doorframes so I don’t hit my head on them at night (I am quite tall, and live in a traditional home in Asia).
Incidentally, I tried building a resonant circuit at 60Hz and was able to pick up a few mV from nearby fluorescent lights – not enough to use. I used a ridiculously large coil of wire that I happen to have lying around. A more fun trick is to use LEDs as their own power source – during the day they work as tiny solar cells, and that lets them flash occasionally at night :D
Hello, I have a circuit that will need to return connected hardware to a default state if power is lost. The hardware can handle continuous voltage, so I’m thinking a simple solution would be to use a battery to provide that fallback power source. To avoid draining the battery, I’d like to connect it through a relay on the...
I sort of hate relays. For 12VDC and a light load, I might consider a depletion-mode MOSFET and a diode to protect the battery. Much faster switching time than a relay, and quite probably lower internal resistance! Also no moving parts and much lower current consumption. There are some cases where it’s not appropriate though.
Anyway, I looked through the datasheet and you’re right – no mention of wear and tear from just leaving the solenoid energized, only from switching. Failure time also seems to increase when switching high currents. Since you don’t seem to be doing either of those things, I think you should be in the clear.
This might not be the best community for this, but I don’t know what job I want after high school. I’m afraid of pursuing a job that I’ll end up hating. How do I figure out what job I want when I grow up?
The best I can recommend is that you try out jobs now – but maybe skip anything ‘fake’ like online courses unless you think they prepare you for what’s in the next sentence. Go find people professionally doing a thing you might like, and try to work with them, somehow. Internships, volunteer work, organizing events, etc. File paperwork and make coffee, if that means you get to see the work actually being done.
Barring that, do the thing yourself if possible. Publish the results. All code goes on public repositories, all stories should be submitted to magazines or literature groups. All songs written must be sung in public. Get certified for CPR and first aid if considering medicine, and volunteer using it. Get an amateur radio license and build a radio. Look at jobs on a freelancing platform, and just do them on your own to build a portfolio (maybe actually apply for the jobs, once you have a portfolio). Not every type of job can be tried out this way, but many can.
You’re going to get rejected a lot, you can’t just show up with a resume and demand a job (people who claim this works are weird). People who create and do nothing will mock you sometimes. A lot of jobs want young people ‘out of sight and in school’ too. However, this kind of disappointment happens to all of us at some point anyway, so may as well get it over with.
If you’re lucky, you’ve got a few years between the age of say 14 and 19 where you’re not expected to support yourself financially but your brain works as well as it’s ever going to. While it’s useful to get good grades while you’re in school (although they are useless afterward), I think it’s a mistake to focus on that at the expense of actually trying to do things. A college degree is too big of an investment of time and money to go into blind.
If you’re in a situation where you do have to support yourself or your family before finishing school, then the necessities of life obviously take precedent. I won’t pretend I have a good solution to that difficult situation.
Next, that I can buy and program a computer for 0.30 USD that’s half the size of a grain of rice (ATtiny10). There are cheaper too, but that’s the one I like.
Finally, on to the horrifying: Boltzmann brains. The idea that given a reasonable interpretation of the laws of thermodynamics, and long spans of time, the most common form of brain in the universe ought to be one that forms due to random fluctuations. It exists for long enough to have exactly one thought (e.g. recall a false memory), then dissipates.
This ought to be by far the most common form of conscious mind in the Universe. In a sense, you could say it ‘blows’ the general case of minds.
Since you are a mind, statistically, you ought to be a Boltzmann brain. You may not be, but are unable to prove otherwise, even to yourself. So either we have some things left to learn about thermodynamics, or the most probable outcome at all times is that you cease to exist immediately after having your current thought (although I hope you don’t). Sleep tight!
It looks like 1GΩ (black-brown-white gold). But that doesn't sound likely unless you have a very high voltage bread maker.
If we treat the black band as discolored-brown, and read it the other way, we get (yellow - white - brown - brown) which is 490Ω and closer to your measured value. I wouldn't rule out (yellow - white red - brown) either at 4.9 kΩ, although that doesn't match closely to your measurement.
A good question is 'why did the resistor burn?'. If I didn't know why, then I would assume that replacing it will just result in it burning again, although maybe not immediately.
...but how in the world do you burn a 1 GΩ resistor? That looks sort of like it could be a 1 watt resistor too. So back-of-the-napkin this would have to be from over a 30kV supply. So that sounds a bit off.
Unless it isn't. One hell of a bread maker then. I want one.
So I wanted to design a children's toy, where the electronics could last 100 years (ignoring mechanical abuse). I figured some people here might be interested....
What I've done is take a large 2n3055 BJT NPN power transistor, and decap it (it is a large metal-can type). Then I carefully removed any coating from the exposed silicon (it typically has a dab of silicone potting compound on it)....
Utopia? Flying jetson cars? Mole people living underground? Everything’s on fire and humanity ends? I’m just curious about anyone’s thoughts in general 😀
I'm taking apart a broken tape recorder produced in the 70s (a Tesla B57, made in Czechoslovakia), to harvest some parts (inductors, switches, ...) and maybe reuse the case for some project....
Grind it into dust, add sand, pour molten non-recyclable plastic into it (e.g. recyclable plastic with too many impurities). Market it as a weighted ballast material e.g. for the base of IKEA lamps.
Mostly I just work in a well ventilated area. Oh and for sure disconnect power before desoldering anything.
Other than that, I avoid taking apart microwaves (beryllium, high voltage), anything with a CRT (imploding glass, high voltage), and high voltage transformers (transformer oil, high voltage). Also any medical equipment (chemical hazard, radiation hazards, biohazard, high voltage, imploding glass). Oh and no unexploded munitions for reasons that should be obvious (people still salvage these in my country and it sometimes doesn't end well).
I find a hot air rework station+tweezers a much faster way to salvage than jamming a hot iron into boards. Also lets you salvage SMT components, which are most of the better parts these days. For 1970s stuff, it's mostly through-hole, I'd test the parts before trying to reuse them. Capacitors especially. Got to love those big transistors from our side of the Iron Curtain though.
I immigrated to Vietnam in 2012. Even though government and society was much more welcoming than this case, the overall experience was... not that different!
Maybe immigration is just a pretty awful experience overall.
So I once made the mistake permitting a client to store some (say a dozen) boxes of financial records in my home for a couple of weeks. By 'permit', I mean they just dumped them there, and I didn't physically restrain them from leaving. This is in Vietnam, where you are required by law to keep your corporate records for 35...
There are a few started on different servers, but I set one up locally. Normally I spend some time on Reddit answering questions from travelers &c as a bit of a public service, but with Reddit becoming boring, I figured I'd give that a try over here.
Vietnam is a friendly but notoriously opaque place, so there is usually no shortage of questions 😄
Sanity check for LiFePO4 Charger Design
So, there are these great 32700 LiFePO4 batteries that showed up in my local industrial market. For like USD 2$!...
How should I get started?
Hello y’all! I’ve always been interested in computers and programming for as long as i can remember, but recently i’ve decided to try to get into some of the deeper stuff behind that, into the wonderful world of electronics. Where should I start? What courses or books or youtube series should I consume? What are some...
Considering positioning strategies for autonomous mechanum-wheeled robots
Disclaimer: this is not specifically for a commercial product, but various things I design sometimes get commercialized. I mention this so that you may decide whether you want to weigh in. If it’s commercialized, I will probably make very little money but a bunch of university students may get a neat STEM program in the...
Learning about electronics
Hello! What would be a good way to learn about electronics in terms of creating them? I’m particularly interested in building my own keyboards and other PC peripherals, but I’m not sure what tools I would need, or what’s a good knowledge base if I run into any issues. Any tips and or suggestions?
Is “harvesting” small amounts of electricity a fools errand?
Serious question from a beginner in electronics. For reasons I do not fully understand, I have become fixated on the idea of collecting small amounts of electricity from “interesting” sources. I don’t mean “free energy”, instead, I mean things like extracting a few mV from being so close to a AM radio tower using two...
Continuous operation of a general purpose relay?
Hello, I have a circuit that will need to return connected hardware to a default state if power is lost. The hardware can handle continuous voltage, so I’m thinking a simple solution would be to use a battery to provide that fallback power source. To avoid draining the battery, I’d like to connect it through a relay on the...
[SERIOUS] How do you do figure out what job you want after high school?
This might not be the best community for this, but I don’t know what job I want after high school. I’m afraid of pursuing a job that I’ll end up hating. How do I figure out what job I want when I grow up?
What is a beautiful concept or idea that continues to blow your mind?
For me it is Cellular Automata, and more precisely the Game of Life....
Why is my food making lightning? (i.imgur.com)
Help finding value of burnt resistor. (lemmy.nz)
Mates bread maker stopped working so I had a look inside and saw this burned resistor....
A nightlight with orientation control
So I wanted to design a children's toy, where the electronics could last 100 years (ignoring mechanical abuse). I figured some people here might be interested....
Not Electronics related: Banner and logo of this community?
Is there a reason why the banner and logo of this community are just the reddit logo?...
Transistor particle detector not functioning as expected (voltage.vn)
What I've done is take a large 2n3055 BJT NPN power transistor, and decap it (it is a large metal-can type). Then I carefully removed any coating from the exposed silicon (it typically has a dab of silicone potting compound on it)....
Since bone is piezoelectric, can I make a working oscillator from it?
I've wondered this occasionally over the years, but never got it working....
What software do you use for PCB design?
I’m interested in learning how to make a proper PCB rather than perf board with wires all over the place.
What do you feel like life will be like on earth in 100 years?
Utopia? Flying jetson cars? Mole people living underground? Everything’s on fire and humanity ends? I’m just curious about anyone’s thoughts in general 😀
Safety tips when disassembling old electronics?
I'm taking apart a broken tape recorder produced in the 70s (a Tesla B57, made in Czechoslovakia), to harvest some parts (inductors, switches, ...) and maybe reuse the case for some project....
Turning something ugly into something beautiful (voltage.vn)
This is a story about something that was entirely unlikely to turn our wholesome, but somehow did....
I can guess what happened here (voltage.vn)
I'm sure someone was complying maliciously here, but I'm not sure who....
"Assume the role of a Chinese immigrant"? 没问题. (lemmy.world)
Dispose of financial records? You got it, boss.
So I once made the mistake permitting a client to store some (say a dozen) boxes of financial records in my home for a couple of weeks. By 'permit', I mean they just dumped them there, and I didn't physically restrain them from leaving. This is in Vietnam, where you are required by law to keep your corporate records for 35...