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Comment by vasco | Hacker News Reader

At the cost of power which will increase your necessary total capacitance.

Digital circuits require some minimal voltage in order for their internal transistors to switch. This is because semiconductors only conduct in the presence of an electric field with a high enough potential to excite and free up the electrons hanging out near their junctions. That means that if your voltage drops below, say 1.8V (common for most low-power digital circuits these days), you won't be able to use your device any more.

There are some very efficient buck/boost converters out there. Like 95% and above efficient. Typically the cost of the power to use a buck/boost dc-dc converter is far outweighed by the ability to convert more of the stored charge into a potential that's suitable to operate the circuit.

Put differently, picture a barrel with a tap on it's wall somewhere near the bottom, and a different barrel with a conical-shaped bottom which tapers into a drain-like tap. Which is more useful? The latter is what you get from a good buck/boost converter.

I've learned something from your comments on this thread, and thanks for taking the time, but you've lost me with the barrels. Pressure depends on height of the water and is independent of the container shape.

benjamincburns was referring to a barrel with a tap "somewhere near the bottom". The point being that it's very difficult to get stuff out near the flat bottom of the barrel, especially if you can't move the barrel itself. The other option with buck/boost converters is if the barrel's bottom tapers into your tap, so that there's no way for any liquid to avoid gravity's call and leave through the tap.

That makes sense. I was over-thinking it.

Thanks for the compliment! As for the question, see what Elessar said.

Also:

In the typical water/electric circuit analogy the volume of water is synonymous to the amount of electrical energy stored (Joules). The pressure of the water is synonymous to the electric potential (Volts). Pipe diameter can be thought of as resistance (ohms), flow rate through a pipe (meters per second) can be thought of as current, and flow volume (cubic meters per second or litres per second) as power (watts).

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