askelectronics

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beeng, in When I was a kid my Dad made a magnet charger with some electrified copper coils would this be something that could be used to achieve similar results somehow? TIA

I magnetize screw drivers with just a normal magnet. What’s your usecase to need such a big magnet?

lossykittens,

I just wanted to recreate the device my dad made with me as a kid

isVeryLoud,

Fun stuff

smpl, in When I was a kid my Dad made a magnet charger with some electrified copper coils would this be something that could be used to achieve similar results somehow? TIA
@smpl@discuss.tchncs.de avatar

Or you could pick up an iron rod and strike a firehydrant like MacGyver.

lightnsfw, in When I was a kid my Dad made a magnet charger with some electrified copper coils would this be something that could be used to achieve similar results somehow? TIA

Do you mean to use it to magnetize objects?

definitely,

You will need to feed it with DC.

lossykittens,

That’s correct!

lightnsfw,

Putting a tool in a powered coil will magnetize it temporarily but I don’t think it will stay magnetic or at least not for long. They sell little magnetizers that you can get cheap that will last a lot longer though if that’s what you’re looking for…

I have one like this around somewhere that worked well when I tried it.

www.amazon.com/…/ref=sr_1_13?keywords=magnetizer&…

nothacking,

Really? If have had good results just placing a screwdriver inside an electromagnet, still magnetized a few years later.

lightnsfw,

Maybe it depends on the coil/power source. When I tried it I was just messing around with a coil I had and 12v source and it was not that effective.

cmnybo,

I’ve had good results discharging a 450V 1kJ capacitor bank through several turns of 10 AWG wire. If you don’t have a capacitor bank laying around, one of those magnetizers will work just as well.

lossykittens,

I appreciate it, I didn’t realize it was so temporary

BrownianMotion,
@BrownianMotion@lemmy.world avatar

Depending on the coils number of windings, and the size of the tool it will magnetise it pretty well. I used to do this to screwdrivers before they came pre-magnetised. And they will stay magnetised for a very long time.

Most of the time the reason for becoming demagnetised is due to dropping the tool several (many) times.

wildbus8979, (edited ) in When I was a kid my Dad made a magnet charger with some electrified copper coils would this be something that could be used to achieve similar results somehow? TIA

What you’re asking is not very clear, but I’m assuming this?

en.wikipedia.org/wiki/Inductive_charging

lossykittens,

Apologies for not being clearer. What I mean to describe is a magnetizer - something that you might put a metal tool through to make it magnetic

tbe, in Struggling to find a PCIe USB controller IC. Either unavailable or expensive

Maybe this: www.microchip.com/en-us/product/PCI11400Unfortunately to access the whole datasheet you might have to sign an NDA (and probably have a large company), also designing things with those kinds of interfaces isn’t trivial.

Alternatively maybe this: renesas.com/…/upd720202-usb-30-host-controllerIt also seems to be locked by an NDA.

elDalvini, in Power device with higher voltage battery and still get battery reading

You could use a voltage divider followed by a unity-gain amplifier to lower the output impedance, about like this: https://discuss.tchncs.de/pictrs/image/e4c6551e-04bd-4969-9494-692723a69d08.jpeg(I think that circuit could work, but I haven’t thought about it a lot, so it might not)

LazaroFilm,
@LazaroFilm@lemmy.world avatar

Thanks for the pointer. Looks like a buffered voltage divider is the way to go. Now down the rabbit hole I go! 🐰🕳️

kebabslob, in Xbox fan issue

Should the fan always be running? Idk about Xbox but some fans on components don’t run 24/7

bl4ckblooc, in Xbox fan issue

Have you looked at any tutorials on ifixit?

Defiant,

I followed a tutorial for replacing the thermal paste

LazaroFilm, in What's the thinnest E-ink screen that is closest to 3.5×2.5 inch?
@LazaroFilm@lemmy.world avatar

For an e-ink display to work you need 4 things.

  • the display itself.
  • a display driver that connects to that flat ribbon cable to the display.
  • a MCU or computer to host your programming and send commands to the display driver
  • power, wether it’s battery, USB, or induction…

You can separate the screen from the driver and have the e paper show the last image. The one thing I’d be worried about is how fragile the components are on the side of the rapper display itself as well as the ribbon cable.

Also, you mention 150+ cards. Think of the time it would take to change each one separately with a dock. Connecting the display to the driver is not hot pluggable you would likely need to power cycle the whole thing at every card. Plus the damage risk of constantly connecting the fragile connectors.

Corkyskog,
@Corkyskog@sh.itjust.works avatar

Thanks, I was aware of some of those obstacles. But this adds a little more detail, to the point where I don’t think it would be economical to repurpose this for this. It sounds like my idea may be possible with current off the shelf tags, but I think the dock would end up being way larger than I was initially imagining. It also seems like I am looking at like a minimum of $500 in parts for a prototype, even if I were somehow able to get the tags for $2 a piece.

You misunderstand the dock interface. The plan would be to insert the ribbon into something more durablee to bridge into the dock to be more like a cartridge. The dock will be expensive as I would plan for either all or most of the “cards” to be docked at once. It wouldn’t be a insert, wait, insert wait, instead it would be insert all the cards into their slots after play.

I also realized that the dock will need to be a little more complex then I originally thought as well. A lot of games have extensive burn and draw mechanisms leading to an extensive set of cards. What you could do is only have the amount of cards you would need in the base set for most of these games that are actually in play at any given time. The rest of the “cards” could be held in the “docks” memory, then “printed” when you draw a new card. It would add a little bit of time to the games, but you could dramatically cut the amount of physical “cards” or tags you need for many games.

LazaroFilm,
@LazaroFilm@lemmy.world avatar

You could potentially modify a game to work with those cards. Making cards able to change state or add extra states (that would usually be extra cards) to a single screen. I like your idea. Maybe the idea would not be a retro fitting but a ground up new mechanics for the mage?

KyuubiNoKitsune, in What's the thinnest E-ink screen that is closest to 3.5×2.5 inch?

I think your best bet is to look for an appropriately sized electronic shelf labels, there are companies that specialise in them and they are already quite thin, battery powered and have bluetooth or nfc connectivity to change images.

pennomi, in What's the thinnest E-ink screen that is closest to 3.5×2.5 inch?

Is certainly in the realm of feasibility, at least in a technological level. You can get flexible e-ink displays that are less than a mm in thickness. Typically the hardware that changes the display is the bottleneck on size.

That being said, I have doubts about the idea of “manufacturing for cheap” as even small e-ink displays can cost $20+.

Corkyskog,
@Corkyskog@sh.itjust.works avatar

I did find some 1mm price tags on Alibaba for 3-5$ which could possibly be repurposed. The issue is I really would like to get the price driven down to $2-1, maybe even less… I want this thing to be able to mimic any kind of card game, and some of them have up to 300 cards… I think the plan would be to have 150 card sets. That would cover a lot of games, and if your playing a really nerdy game that does need 250+ cards or something there is a chance your friend might also have a set.

If you could get the price tag $300 or less you could probably get a lot of hard-core tabletop card gamers. I know thats a huge price tag, but the product isn’t meant for the masses.

ciko22i3, in What's the thinnest E-ink screen that is closest to 3.5×2.5 inch?
@ciko22i3@sopuli.xyz avatar

Try finding it on AliExpress. Just search “e ink display” or "e ink screen. The webiste is hot garbage but their app is ok.

Corkyskog,
@Corkyskog@sh.itjust.works avatar

Thanks I did try before, but now I had success. I stumbled upon those little price tags stores use to digitally update prices. Those could possibly work for this.

ciko22i3,
@ciko22i3@sopuli.xyz avatar

good luck

your project sounds really interesting, make sure you post an update when its done

SpaceNoodle, in What's the thinnest E-ink screen that is closest to 3.5×2.5 inch?

Even if you find screens that thin, all the electronics you’re going to need to make them usable will add considerable thickness.

mp3, (edited )
@mp3@lemmy.ca avatar

But once the display is updated, the circuitry isn’t really necessary. Maybe you could reduce the thickness and the duplication of circuitry by having a “dock” with the circuitry where you insert the card to update it.

Corkyskog,
@Corkyskog@sh.itjust.works avatar

That’s exactly the idea! They would have pins somewhere on the buttom, you would plug all your “cards” into a dock that would act as a carrying case. There would be an open source website where people can design different games and then you choose one of the games and it refreshes all the cards to whatever game you want to play.

That’s the idea anyway, whether it’s feasible for something people are willing to pay is a different question.

BlueAure, in Considering positioning strategies for autonomous mechanum-wheeled robots

Assuming that there is at least some amount of slippage between the wheel and ground, it seems to me that you’ll need to regularly check the ToF sensors anyway. I’ve found that encoders are fantastic for a lot of things, but not so much for measuring distance because of the problems you’ve described. Perhaps a recurring local check on a reduced set of points to verify location then forward the full cloud less often for further remote processing? It really sounds like you have a tradeoff depending on whether you value accuracy of location or accuracy of wheel rpm (analogous to speed). Using both would give you a nice way to calculate the ideal motor rpm to minimize slippage in a surface agnostic way.

Saigonauticon,

Ok yeah – I’m leaning toward relying more on the laser ToF than the rotary encoders.

A simple algorithm of ‘pick a lidar point and drive toward it’ does sound simplest. Thanks for weighing in!

Reader9, in Replacement Bulb for Ultrafire WF-500 Flashlight

I found a few references to this exact model on candlepowerforums.com which I believe has more folks who own(ed) incandescent lights. Not that has been such a long time, but LED technology advanced very quickly. Not sure if that will help your search.

There’s also a few people over on !flashlight !

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