My local children museum has something like this. Let me see if I can find a picture to give you an idea of the set up. It does look like it would be $$$ for set up. What’s your price point?
Cool! I’m still looking for a picture. I’ll post when I find it but thinking about this more I know there are a ton of toys like this made. Most are for older kids and are priced at about $20-80.
Look up circuit station kids science and you should get an idea of the kits.
My kids had Snap Circuits but it’s a bit complex for a toddler. It’s probably the most basic circuit designer I can think of though. They did a great job. If an adult is helping it would be fun for both.
Yeah around three they should be able to do it with adult supervision but it’s still a bit of a toss up on if they are going to put the small parts in their mouth. I can’t find the a good photo of the big one at my local children museum. It’s going to drive me crazy. I’ll probably just have to take a picture next time I go in.
I’d suggest peeling off just one strand of the wire and use that. You will need to insulate the wire from the nail - Wrapping paper around the nail will do. You will need to insulate the wire from itself, so that adjacent turns don’t touch. You can just space the turns out along the paper sleeve. That should do the trick. If you have twine, you can wind that on with the copper wire and use the twine to keep the turns from touching each other.
Oh to straighten copper wire, if you don’t know this trick - hold your nail in a vice and wrap a single turn of copper wire around it. If you then pull on one end of the wire, keeping a little tension on the other - with a bit of practice it will give you a very straight end result, as the wire pulls away from the nail.
Maybe give the tool and helmet a white outline too: easier identifiable
and another idea would be to mix into the question mark an electrical spark but that are only some random tired ideas.
That are like the only things i found to edit, not sure if it is improvement
The fundamental concept at work in making an electromagnet is Lenz’s law. Here’s a Khan academy video on the topic. www.youtube.com/watch?v=xxZenoBs2Pg
You can determine the power of a magnet (very roughly) using the following equation:
B = μ₀ * n * I
Where:
B is the magnetic field strength in teslas (T) or gauss (G). μ₀ is the permeability of free space, approximately equal to 4π × 10^-7 T·m/A. n is the number of turns per unit length of the coil (turns per meter). I is the current flowing through the coil in amperes (A).
So the number of turns matters, and also the current matters.
But there’s a third thing, and I think that’s the problem you’re having: This piece of wire is conductive, and the nail is conductive, and there doesn’t seem to be any insulation on the wire. Because of that, the current flows through the wire on one side, into the nail and across it, then out the wire on the other side. The current needs to flow in loops without being able to take any other path, The coil of wire and the current flowing around in circles is what’s required.
What you want is a long piece of wire with insulation on it. Then you wrap it around the nail, and then apply a battery across the wire. A 1.5V battery probably won’t have much punch so you might not be able to get much of a magnet, but a 9V battery should do it quite well. What will happen is the current flowing through the wire will create a magnetic field, which will magnetize the nail, which will create a magnet you can use to pick up coins.
A lot of the time, people run demos using special wire for creating magnets that’s copper with a very thin clear insulating coating on it, so you might think you’re looking at someone just making a loop of regular wire, but the insulation is key to the whole thing working.
In my experience a large 1.5v D cell works best, as the limiting factor is generally current not coil resistance, unless you wind thousands of turns of fine wire.
The standard way of looking at this is to consider a capacitor-resistor series combination going to ground. Connect a 10v (wrt ground) supply to the capacitor and the voltage across the resistor rises to +10v, then decays. Now connect that capacitor to ground and that same resistor gets -10v across it, which then decays. Whatever is connected to the capacitor “top” terminal has to be able to sink current as well as source it.
That’s what generators in simulators do - they have zero internal impedance (usually). They sink currents as well as source them.
pressfit connections usually are very reliable. if there is a poor connection i would presume that the barrel of the via is broken and a new pressfit connector will not help. maybe putting solder in would help. did you already test for poor connections?
Barrel of the via? I’m unfamiliar with that terminology – what is that? I did a continuity check from the very bottom to the very top and everything tested good. When the audio is out, twisting the header a bit would usually bring it back so I assume(d) it was just a poor connection somewhere despite the continuity check.
EDIT: Okay, some quick Googling got me understanding this better. As I mentioned, continuity is good, but I still suspect it’s something in this area. I suppose I could remove the connectors and install solder connectors, instead of press fit?
yes i think so, but u would have to make sure the solder will rise through the through-hole as mich as possible. maybe u can try to find the faulty pin with wiggling them separately
That’s why they call it a decoupling capacitor, cuz you usually just need AC (signal) at the out of a circuit, you don’t need the DC part of the signal.
True AC is sort of “balanced” in that it has just as much positive as negative. The positive area of the waveform is the same size as the negative area. For waveforms that are sort of symmetric across the 0V with a time offset, such as a sine or square wave, this means that it is centered along the 0V line. A DC source, on the other hand, never changes voltage.
The 0V to +10V source you have is actually a -5V to +5V square AC plus a +5V DC. The capacitor is getting rid of the DC component leaving just the AC, which happens to be the -5V to +5V AC that you are getting.
In my opinion an oscillator always produces an AC sine wave. There is usually no need for a DC overlapped oscillator signal. The DC supply of an oscillator produces a AC sine wave relative to GND.
Where exactly did you measure a DC sine wave, relative to what, and what do you mean by “AC removes a DC component”?
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.
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
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)
You’re right of course. Two more questions if you don’t mind:
what’s the 1k || 100k doing?
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.
it does nothing 😅 I just forgot to remove it from the sim
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 :)
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