Can resonant circuits be self-powering, and not use capacitors
Check :
https://en.wikipedia.org/wiki/LC_circuit
( I'm also refering to the other circuits on that wikipedia-page, RL circuit, RC circuit, RLC circuit )
There's no power-source mentioned on that webpage, and yet for all other types of circuits on wikipedia, they always mention the power source .
- Although, yes, I assume that this circuit receives power from other circuits, via inductance, via it's coil, however, look at the first diagram :
https://en.wikipedia.org/wiki/File:LC_parallel_simple.svg
There's no load on that circuit, just a coil and a capacitor, self-powering ............
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Do Resonant-circuits, have to use capacitors
It seems they do not actually need a capacitor, there's probably more than one way to not use a capacitor, the method below is interesting, find the text, "no capacitor", on the webpage below :
https://www.electro-tech-online.com/threads/crystal-radio-only-gets-a-far-away-station.124197/
The diagram on that webpage, is only visible by using the link below :
https://www.google.es/search?q=site:.electro-tech-online.com/threads/crystal-radio-only-gets-a-far-away-station.124197/&rlz=1C1AOHY_enES712ES712&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiE6-6ajMLZAhUGaxQKHTrcDqQQ_AUICigB&biw=1024&bih=485#imgrc=oYaXqQRDHFAvPM:
A crystal receiver, whether tuned to a terrestrial radio station,
or an astronomical source, draws power from an external signal.
This serves the same function as a battery.
And therefore is not "self powered"
The power comes from somewhere, either a star emitting radio frequencies
or a radio station powered from the electrical grid.
I've edited the first post, so that the crystal-radios web-link, is clearly only part of the question regarding capacitors
LRC's (or even the theoretical purely LC) have system losses
They are neither self-powered nor self-sustaining