I advise reading previous update ("Bye, DC!"), it's a crucial part - it contains important ideas about power & energy in electric circuits, revealing phenomenon of inductance and resistance on a new level - now it's my instrument of choice for working with electromagnetic processes.
Hello everyone! Again : )
Previously, I described a proportion, in which power allocates between charging electromagnetic field and heating a conductor and it was a bit of a shock for me, originally I wondered, how we can eliminate heat dissipation completely. Now it seems impossible? Not quite!
I see two ways, how to come round that heating misconception:
1) We can develop a new sort of electromagnets! If we assume, that proper distribution of charge in space (and not specifically in a conductor) creates a magnetic field, that means, that we can recreate it similarly to a capacitor. It would be a charge-dependant electromagnet, which can store electromagnetic energy as long, as charges present in it. In a traditional coil waste of power dictated by a unstable state of charges, covering a conductor - you need to apply external "force" to prevent "positive and negative charges" from collapsing, that's why applying voltage is an essential thing there. However, I failed to notice any sort of a magnetic field around flat capacitor. It doesn't mean, that it's 100% not there - it's probable, that Earth's magnetic field outruns weak field of a capacitor - it requires more studying. If I would get an idea how to make such a thing - I would share it here. It would be epic, if it's possible ; )
2) We can exploit an interesting behaviour of a traditional coils. More on that in next part:
Even an energy dissipation law has it's own backdoor! And this backdoor is a fact, that if you apply no power to a conductor and retrieve most of energy, that it gives to you, it's not likely to dissipate something into the air. Current might stay the same, who cares!
I made some measurements:
I submerged my electromagnet into a vessel with water and powered it up, recording changes in temperature. It takes about an hour to temperature to drop down for a 2 degrees in this setup, as it features some thermal insulation after all, water volume stayed untouched
Here are results:
Control circuit changed situation a lot - reducing energy dissipation for about 30%
On the right side you can see oscilloscope date, isn't it looks familiar? :)
That then, 30% is our upper limit? Not at all! Retention of energy goes on a constant rate independently of a charging rate, as it is a typical LC oscillatory circuit. We can use it in our favour, increasing charging speed. Here are few samples with another electromagnet: