Duals and Duels

Point 1: Maslow's Hierarchy

Point 2: Economica:

There was a movie, directed by Dr. Charles Venus, about economics. It featured flow charts showing goods moving from supplier to factory to customer - with money flowing the opposite direction. Credit and Debit, Electrons and Vacancies if you believe in the Solid State.

At the time, the critical necessities were Food, Clothing and Shelter. Which is great for a Cave Man living in the Stone Age. For those not living in solitary confinement an updated list is:

(Economic-Necessities

     Food Clothing Shelter Information

)

The last entry, information, implies communication, education, entertainment, PC's, TV's and cellphones.

Point 3 Duals and Duels:

ADC - DAC

The input to an analog-to-digital converter (ADC) is some measurable feature of the real world. The loudness of a moment in time perhaps. The output, quantized to a digital representation is a superposition of, "Yes, I heard it", or, "No I didn't".

A digital-to-analog converter does the opposite. It converts a digital number to an analog signal.

A good way to test an ADC is to undo it with its inverse, the DAC. One compares the real world to the real world run through the ADC-DAC combination. If the measurements are the same, you have a perfect ADC and DAC.

One can make a similar remark about DAC-ADC combination.

The idea is this: One can test a thing using its dual. The dual of the ADC is the DAC and visa-versa.

I find this simple idea to be one of the most useful ones I know.

VTF-FTV

A similar argument applies to a voltage to frequency converter (VTF) and a frequency to voltage converter (FTV). These devices exist on integrated circuit chips. The same chip can be run one direction to be a VTF and the other to be an FTV. It is a profound thing to convert a signal in the time domain, to a signal in the frequency domain. Each representation has its strengths and weaknesses. Moving a signal into the frequency domain makes some things, like filtering, very easy to understand.

HW-SW

Hardware (HW) and Software (SW) aren't really duals in the sense of the other examples. I have a friend who likes to move functions into software. I would like to see more things move into hardware. So we duel, in a friendly way of course. But you may be getting an idea here and I will leave you to that way of thinking.