There are many devices into which you can input energy which will store it and then let you take it out at a greater rate, but the total amount of energy that you take out will always be less than what you put in.
Two thoughts - you appear to be suggesting the electrical equivalent of the Holy Grail - getting more out than you put in, or even getting something out without putting anything in.
That has not been discovered yet, but if you have the answer keep it quiet and I'll invest with you in it.
But the other issue is - if you want to charge something up then use it as an output without the supply - then that is possible.
Perhaps the most common example is the UPS system, a battery system which is maintained and charged from the input supply, but can then provide the limited output, without the input.
We need some more information to help you further.
If I'm reading your question correctly, no, it's not possible.
In effect, you're suggesting that I could take a step-up transformer and connect the output back to the input and have unlimited source of power.
In electronics, an amplifier that feeds its output back to the input is a positive-feedback amplifier (as cnpower mentioned already) but it cannot be a continuous source of power.
Good evening.
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