You probably don’t think much about charging your phone. Just find an outlet, plug it in, and wait a while. Can’t find a cable or wall wart? A rainbow of cheap, candy-colored options awaits you down at the brightly-lit corner drugstore.
This scenario couldn’t be further from reality in third world countries like Papua New Guinea, where people living in remote jungles have cell phone coverage, but have to charge their phones by hooking them up directly to cheap solar panels and old car batteries.
[Marius Taciuc] wants to change all of that. At the suggestion of his friend [Brian], he designed an intermediary device that takes any input and converts it to clean 5 volts with a low-cost, reliable buck converter. The inputs are a pair of alligator clips, so they can be connected to car battery terminals, bare-wire solar panel leads, or 9V connectors.
Mobile phones mean so much to the people of Papua New Guinea. They’re like a first-world care package of news, medical advice, and education. At night, they become simple, valuable lanterns. But these dirty charging hacks often lead to house fires. Someone will leave their phone to charge in the morning when they go off to hunt, and come home to a pile of ashes.
This is an open, simple device that could ultimately save someone’s life, and it’s exactly the type of project we’re looking for. [Marius] hopes to see these all over eBay someday, and so do we. Charge past the break to see [Marius] discuss the Brian Box and the people he’s trying to help.
“This scenario couldn’t be further from reality in third world countries like Papua New Guinea, where people living in remote jungles have cell phone coverage, but have to charge their phones by hooking them up directly to cheap solar panels and old car batteries.”
*shows picture of a phone with a USB port*
Sounds like quite the hack in itself.
Phone with a usb port??
Unlike here in the US, where even the most remote fly-over farmland has access to reliable electricity…
But little or no cell service.
so he recreated the mobile phone cigarette lighter charger. well the 9v support helps at least.
I think you missed the point. It’s not just for 12v car batteries, it’s for a wide range of inputs. One case he suggests is directly connecting the Brian Box to solar panels. And conceivably any other source of current.
Most CLAs, by necessity, have fairly wide input voltage range. In fact, most likely a large proportion of them use the very same LM2596
Yes but it’s better because it’s “open hardware” and in a “3D printed enclosure”. Obviously perfect for parachuting in and solving all the problems in a third world country! :P
Sarcasm aside, it’s at least a reasonable design, with reverse polarity protection and actual documented ratings, and what looks like reasonably high-quality components, all things that your typical cheapo cigarette lighter socket charger don’t have. Things I’d add (having designed one of these that never made it to market, but I use in my car):
1) A fuse! If the whole point is safety, add a fuse so any fault in the circuitry has a better chance of causing a predictable failure mode that isn’t fire.
2) Charge negotiation: Dedicated chips like the TPS2514 can provide a variety of signalling voltages on the D+ / D- pins to convince various manufacturers’ phones to charge at full power, rather than limiting to 500mA or not at all. For an even lower cost solution, some phones accept just a single resistor (or even just shorting D+/D- together), the chips are just nicer for a more “universal” approach.
3) Consider input overvoltage protection (again so it doesn’t catch on fire) — This could be as simple as a zener / TVSS diode after the fuse (or polyfuse), or a dedicated comparator chip, etc. This depends on the design environment too — if it’ll never see more than a 12V battery, it’s fine. If it is advertised as connecting to any solar panel, there are solar panels with 36-38V open circuit, which is getting uncomfortably close to 40V. In my case, the design was targeted at a fixed installation that could see spikes of up to 80V, so I had a design max of 80V, overvoltage protection at 85V, and components rated at 100V.
4) A fuse — just thinking about this more, a user could see “universal application” and not understand voltages and attempt to connect directly to an AC line. This could not only destroy the device, but also their connected mobile device if the high side switch failed short.
Why not AC line? One could make a truly universal AC, DC 5V to 300V adapter, with all the protection above.
Yup, just a matter of design goals and complexity. Getting to that wide of a voltage range is harder, and you probably want isolation for AC line connected stuff, as well as needing more capacitance for dealing with 50/60Hz. Could probably be done though, I’d be curious to see what kind of topology would be used for this kind of design.
I am glad you came around, I thought you were going to give linguist a hard time for wanting to save a guy’s house in his free time while also saving his language and culture. SIL linguists do great work. Searching Alibaba and eBay don’t yield solutions for this particular problem. Perhaps the goal is to promote visibility to a global need so that it will get ripped off, and produced en masse so that a single days wage can afford a safe charging solution. To think of it, the info posted above could lead to a better product if detailed out on the project page, then your previous experience could benefit a wide swath of the world instead of just your car.
May I propose a diode bridge to deal with polarity reversal as well as (to some extend and with proper filtering) AC uses?
Who knows, maybe someone can use some kind of stepper motor mounted on a bicycle or I don’t know what?
Yup. I mean, it works. And if he spent the money on international post, he could send that one to a Papua New Guinean. But that doesn’t actually help the rest of them.
Something more in-field would be better. What if you put a car indicator light in series with the battery and the phone? Or I dunno, knock up a resistor out of charcoal or something? If the PNG’ns had access to boost convertors, they’d use them. They obviously don’t! And that’s what this is!
The 3D printing, I’m not even gonna go into.
What might help is to found a charity, buy up a shitload of cheap Chinese cigar-lighter convertors, after testing to find one that isn’t just a straight-through wire, and then ship them across.
I have got to be missing something here.
Buck converter with 5V USB output, they _are_ all over ebay.
Here’s one $8.43 US for 10, free shipping:
https://www.ebay.com/itm/10PCS-6-24V-12V-24V-to-5V-3A-CAR-USB-Charger-Module-DC-Buck-step-down-Converter/112555369628
Ok, that one max input is 24V, here’s one that’ll do 40V and has a meter on it for $2US
https://www.ebay.com/itm/DC-DC-buck-power-supply-module-6-5v-12V-40V-to-5V-car-voltage-meter-USB-S7Y7/253314983659
Cheaper yet on various Asian websites, but the point stands.
There are plenty of buck converters that do this already. Cheap, water proof, and ready available on eBay. Their efficiency is about 70% but for $3 on eBay not much can be said. Inputs from 7v to 24v output is 5v. The package is nice though.
Non problem nicely solved.
Sorry I can’t be more positive; I live off grid and phone charging is the least of my problems; cigar lighter, job done. (Majority of cigar lighters also work at 24v anyway for lorries) In any practical solar installation a stable 12v supply has a broad range of uses because of cigar lighter compatibility and it’s cheap off the shelf. Single solar panels are quite happy to take a direct cigar lighter connection for phone charging purposes.
I can’t really be that positive either. It looks like a reduced component count of the Ti Application Note for the IC.
Also …
Q: How many of these things already get churned out from china by the bucketload?
A: Lots.
The first one I pick up
https://www.ebay.co.uk/itm/Dual-USB-DC-Buck-Step-down-Converter-6v-12v-24v-36v-to-5V-CAR-Charger-Module-DIY/131735583365
And one that’s really quite similar…
https://www.ebay.co.uk/itm/9V-12V-24V-36V-to-5V-Dual-USB-DC-Buck-Module-Step-Down-Converter-Charger-Module/253107221587
Which isn’t really *that* surprising considering the Chinese are very good at reducing component count.
I like the application of the idea though.
I don’t like:
1. Pick a cheap product from China
2. Add a 3D Printed enclosure
3. ?? (get featured on hackaday?)
4. Profit !
How much noise is on the output though?
https://lygte-info.dk/review/Power%20Adjustable%20buck%20converter%20LM2596%20UK.html
okay yeah but to comutate in the parlance of AvE, is the $3 chinesium especial skookum or is it going to be sending you smoke signals from your wigwam after 6 months when an ant (or uncle no diisriminatin) bridges the half a blond one’s gap between the high and low voltage sides.
Or if you don’t speak Bumblefuck let me say this, what kind of fool thinks that leaving people’s live and livelihoods to the ali-express lottery is a GOOD idea. Well you for one, apparently.
But featured adapter is just the same as those AliExpress modules, no additional care is taken about PCB clearances, noise filtering and thermal management. And if you doubt chinesium products you should use brand name ones like Sony and Samsung, they’re completely fire-proof, as we know.
It’s just a buck/boost converter in a crudely 3d printed box… I don’t mean to be an asshole, but the converter has been around since the 1920’s. What’s new in this project? The box? The bone shaped box, which is just insulting when you consider that the target audience (jungle dwellers in Papa New Guinea) used to practice cannibalism.
FFS! A buck boost converter is only 1.46USD with free shipping on eBay. How much does one of these units cost to produce? Good luck getting the electronics below 5 bucks plus assembly… AND THE FRIGGING BOX!
The man clearly illustrated the market for a SAFE, RELIABLE, wide input buck converter.
I think someone needs to listen to Big Clive’s “cheap shitty pink USB charger from China” song again.
https://www.youtube.com/watch?v=Cn02XaLMrnI
So? Spend a few extra bucks (pun not intended) and buy the safe option. Point is that the market is full of step-down converters, some of which are also safe. And these converters already have a production in place with a supply chain and distribution channels. There’s no way you’re going to beat the other chargers on price.
Besides, the safety mentioned just aim at being better than plugging solar cells directly into your phone. That doesn’t take that much effort.
The product is redundant, the production primitive and the project has no place being featured on hackaday.
What is the inovation? put 2$ buck converter module with USB connector into 3D printed box? Sorry but I think this is quite poor project for hackaday. I understand limited resources and money in developing countries like papua new guinea, but for this purpose I will expect clever solutions, true hacks, something how to build efficient device with advanced features for very cheap. Not buy chinese module and spend 2/3 of budget on fancy 3D printed enclosure.
Hmm, so it’s just a shitty ebay module with questionably fake silicon and cheap high ESR caps in a 3D printed box.
No solar panel MPPT control, no overvolt/overcurrent/reverse polarity protection, no way to communicate with the device to negotiate charge current, not waterproof….
I guess it’s a proof of concept, but add a few safety and reliability improvements in the next revision for sure.
My local RC/modeling store has these BEC units (basically step down converters) that take anything from 0-30V in and 5V out (tunable with a little pot) at 10A max. They are about €15 here, and probably cheaper if you order them from some chinese online stores etc.
Is this any cheaper than a decent quality ciggarete lighter charger?
> buy a DC/DC converter from ebay
> make a 3d-printed case for it
> ???
> appear in Hackaday
Wow. Thats underwhelming. The Teaser made me think of a well engineered Product with really cool Features like MPPT when connected to solar panels, a spectacular range of input voltages (e. g. 1V to 450V DC/AC) and other cool features. Further reading revealed an off the shelf chinesium buck converter with a not even waterproof 3D printed enclosure, descriptions in .docx format (WTF??) and totally worthless blablabla.
Where is the ‘hack’?
Sorry for the rant guys, but what’s wrong with you?