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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

LazaroFilm, in Replacement Bulb for Ultrafire WF-500 Flashlight
@LazaroFilm@lemmy.world avatar

My opinion: look for a new LED flashlight. It will have the proper circuit and design to take advantage of LED capabilities including high brightness, PWM dimming, power efficiency, and heat management. Adapting an incandescent flashlight will always be a compromise in one of those.

Edit: I have a similar flashlight and I bought a tiny usb-c rechargeable flashlight that is brighter for 1/5 of the size. And for battery life, you can recharge your keychain size light with any usb battery pack.

TCB13,
@TCB13@lemmy.world avatar

Yes, feature and price wise that would be the best decision… but I kinda feed bad trashing a perfectly good machined aluminum piece just because of a bulb. :(

Eheran, in Transformer question
  1. Insulation. Physically separating the two sides makes sure there are no issues.
  2. The difference in magnetic fields distance is fairly irrelevant with a core that is really good at “conducting” magnetic fields.
TheHobbyist, in Transformer question

I’m not sure I understand your proposed solution, but the ferrite core guides the magnetic flux, there are very few losses, and both circuits are perfectly electrically insulated from each other. How would your solution be an improvement?

h3ndrik, in Communication protocol suggestion for peer-to-peer device network?

maybe RS-485 or CAN

surepancakes,

Thank you for your suggestions. Rs-485 seems to be what I was looking for. CAN could also work, but is it reasonably implementable? So far everyone who I spoke with about CAN said that it is a rather complex protocol with a lots of finicky details and an extra long standard. Perhaps I have just talked to the wrong people. I will look into it more thoroughly, and thanks again.

h3ndrik,

I might be a bit spoiled by the ESP32 and all its supported protocols.

wildbus8979, in Communication protocol suggestion for peer-to-peer device network?

Sounds like you want ethernet.

surepancakes,

Hmmm… It does tick a lot of the boxes, but the ethernet protocol is way too complex with all of its layers and not reasonably implementable on a low-power microcontroller. Also it requires separate hubs for connecting multiple devices together unlike i2c, which is daisy chainable.

wildbus8979,

A lot of microcontrollers, ESP32 or STM32F4 to give two examples, have the PHY built in.

But if that’s too much for your taste, then CAN bus might be what you’re looking for.

Lemmesee, in What is this "220?" component and how do I determine a compatible replacement?

Looks like a 22 ohm resistor

grasib, in Attempting to repair controller, Have I damaged it beyond repair?

You lost your pad. This usually happens if you have old PCBs which were exposed to some air humidity over time. The pad heats up and the moisture evaporates between the layers, separating the pad and the PCB base material. More heat increases the likelihood of that happening.

That part is unsolderable now. You need to connect at a different place and reconnect any interrupted traces or glue the pad back to the board, if you can.

Game controllers in general are very hard to repair since they contain large copper layers to withstand forces from the controls. It’s very common to loose pads or lift THT holes.

That said, most often nothing is ever beyond repair. It’s usually just a matter of skills and tools which are available.

Rolive,

Hmm so you could work around this issue by placing the PCB in a drying oven a couple of hours before. Something around 50deg C.

grasib,

That is correct, this is the standard procedure to dry PCBAs.

LowQualityGoods,

Thanks, I’ll try and find the trace and solder a wire and maybe some supports.

MajorTom, in Attempting to repair controller, Have I damaged it beyond repair?

I can’t tell for sure, but it definitely looks like your pad is gone. If you have an exacto knife you can just gently scrape away the solder mask, find the trace, and solder to the trace.

LowQualityGoods,

Thanks, I was worried about trying this, but if it’s my only option I’ll give it a go after I try another clean and resolder.

LazaroFilm,
@LazaroFilm@lemmy.world avatar

Basically it’s broken right now. You can try and fix it and it will either work (yay) or not (so just like now) you have nothing to lose. Worst case you tried something new and learned things!!!

th_in_gs, in Soldering Iron Tips Stop Working/Melting Solder

I think it might be a controversial topic, but I’m fond of tip tinner - something like this:

www.amazon.com/dp/B00NS4J6BY

Brgor, in What type of connector is this ?

That’s a SAS connector, but unfortunately it won’t work with your computer without a SAS card called an HBA or Host Bus Adapter.

elDalvini, in Electronics for toddlers?

As a young child, I had a wooden board with a bunch of different light switches mounted to it. Nothing to tinker with, but I had a lot of fun with the physical sensation of switching them on and off. I think that’s all you can really ask for at that age.

Later on, I enjoyed taking the switches apart, figuring out how they work and using them in my electronics projects.

My point is, whatever you choose should be physically fun, even without understanding it. A few switches and maybe a blinking light can entertain a toddler for a long time. The tinkering can come later.

grasib, (edited ) in What's a simplest way to get -5v from +/-12v?

Supply the OpAmp with +/-12V or +5/0V and use a non inverting Summing OpAmp Circuit to get your 0-5V signal. V1 is 5V, V2 your input.

PinkDuck,
@PinkDuck@kbin.social avatar

thanks! gonna give it a try tomorrow. I'm pretty new to this, and never used opAmps in non-inverting configuration, so I missed this option

grasib,

Exiting! It has been some time for me too, let me know how you solved the problem at the end.

PinkDuck,
@PinkDuck@kbin.social avatar

it worked! (at least in the sim)
thanks a lot!
I'm not sure I got all the math right, since I get 0 - 5.05V on the output, but it's not a deal breaker for me.
I attached the schematics, but not sure that images in comments federate from kbin to lemmy, so if you don't see it, try opening an original link to this comment.

PinkDuck,
@PinkDuck@kbin.social avatar

ah, a little bit of thinking helped me realize that I don't need 1k in inverting loop and then I'll get 5v instead of 5.05v :) and 100k can also be replaced by 1k

grasib, (edited )

So what should happen if you replace the 1k in the inverting loop by 0 Ohm is, you should get a 5V square wave.

Is that correct?

PinkDuck,
@PinkDuck@kbin.social avatar

No, with 0 Ohm I get a perfect 0+5v sine, just as I need. It's the other way round, it'll amplify the signal and clip off the top at about + supply voltage when you increase the resistance in the feedback loop, but it's not exactly square wave, as the bottom part of sine will remain intact. I use clipping schottky diodes to protect the arduino from voltage outside 0+5v range, this way if you increase input signal to say 20v peak to peak, you'll get more square-ish wave in 0+5v (I've attached the schematics)

grasib, (edited )

You’re right of course. Two more questions if you don’t mind:

    1. what’s the 1k || 100k doing?
    1. if you don’t want more than 5V at the output of the OpAmp, wouldn’t it be easier to just supply the OpAmp with 5V instead of adding a shottky diode which has a forward voltage of around 0.6V? As I understand the screenshot the voltage is 5.4V at that exact point and it could theoretically raise to 5.6V.

At the moment you’re also mixing up your + input. 10V AC + 5V DC result in 7.5V input in your sim.

PinkDuck,
@PinkDuck@kbin.social avatar
  1. it does nothing 😅 I just forgot to remove it from the sim
  2. you mean like power it with 0+5v? I think it won't work with negative input voltages then, right? and I'm using tl074 and I'm not sure that 0+5v is enough juice for it, and I use remaining 3 opamps for other stuff, so it's not really an option for me. the sim didn't have shottky diodes, so this measurements are not 100% accurate, but I used this approach to protect arduino inputs in another project, and it worked well. And yeah, I cranked up the input signal to +/-10v just to check the clipping, it'll normally stay within +/-5v

I already ordered PCB for the prototype. I hope it'll work fine. Thanks a lot for your help :)

opensesame11, in What software do you use for PCB design?

I use Altium Designer and KiCAD. KiCAD isn’t as good by just a hair but makes up for it by being free and open-source. Altium Designer is also crazy expensive for hobbyists.

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