> The average 1950s family only owned one car, while the average family of today owns more than one (likely, to support the second job)
Actually, it's an even greater difference than that. The median household income in 1955 was about $4k, while today it's about $50k. In 1955 the cheapest Ford cost about $2k, or half the median household income, whereas today the cheapest Honda costs about $16k, or a little less than a third of median household income.
If we just leave it at that, it sounds like things are about the same. However, the cheapest Honda today comes with airbags, air conditioning, power windows and locks, an FM radio, and a whole host of other features that were luxuries reserved for the most expensive cars (if they were even available at all). On top of that, my (and others') experience with modern Hondas is that they can easily go for 200k miles without major repairs or tune-ups, whereas 100k miles was considered a major achievement for a Ford of that era. Realistically, this difference in longevity alone means that a car from the 1950's cost about three times as many working hours as a car of today.
>> Internal adapters are a lot messier for 120v.
>Why do you say that?
Well, for starters, most for-profit enterprises like to avoid liability. 20 V things are considered "low voltage" for regulatory purposes while 120 V things are considered "high voltage." That has certain implications for how you have to electrically insulate your portable device.
Then you also have to consider the difference between AC and DC. A power supply meant to connect to the wall has to have an energy storage device (usually a capacitor) for the 120 times per second that the wall delivers no energy.
Designing and manufacturing a device to power from 20 VDC (+/- 10% or so) is amazingly easier than one that must slurp 120 VAC.
>Basically you would need 20v -> 5v vs 120v -> 5v - there isn't really a lot of difference
This is completely wrong. 120 VAC is 120 V RMS, which has peaks of +/-170 V. Go to digikey and compare the price of 340V capacitors to 40V capacitors. Then consider the fact that your low voltage capacitors only need to filter relatively high-frequency ripple and occasional step-loads, while your high voltage caps need to supply energy when the wall isn't (so they needs to have much more capacity).
Actually, it's an even greater difference than that. The median household income in 1955 was about $4k, while today it's about $50k. In 1955 the cheapest Ford cost about $2k, or half the median household income, whereas today the cheapest Honda costs about $16k, or a little less than a third of median household income.
If we just leave it at that, it sounds like things are about the same. However, the cheapest Honda today comes with airbags, air conditioning, power windows and locks, an FM radio, and a whole host of other features that were luxuries reserved for the most expensive cars (if they were even available at all). On top of that, my (and others') experience with modern Hondas is that they can easily go for 200k miles without major repairs or tune-ups, whereas 100k miles was considered a major achievement for a Ford of that era. Realistically, this difference in longevity alone means that a car from the 1950's cost about three times as many working hours as a car of today.