Around 6.3V was a standard voltage for vacuum tube heater pins (the part that emitted free electrons via thermal emission inside the tube to be available for the electrical fields to accelerate).
My guess would be that historically 6.3V supplies made forvacumee tubes where commonly available when transistor based electronics where created so it made sense to utilize them. Works quite nicely for the typical 5V circuits as a "rough" input voltage to be feed through a LDO regulator, for example. And so it just stuck.
6.3V is the standard voltage of a farm tractor battery --these vacuum tube heaters were designed to use them.
12.6V is two farm tractor batteries (one car battery), which is why our computer industry uses 12V for motherboards (12 volts - 0.6V reverse protection diode).
Early computer power supplies used voltage regulators that were designed for car radios, originally.
Farm tractors and cars switched from 6 volt to 12 volt at about the same time, and for the same reasons. However the old 6 volt farm tractors are still around and used for framing, while 6 volt cars are rare collectors items (even though there were more of them).
Some people in the auto industry want to double the voltage again (for efficiency and to reduce the weight/complexity requirements for all the wiring, especially in EVs) but the 12 volt standard is pretty entrenched.
(Note that I'm talking about the voltage used for everything outside of the internal engine/li-ion electrical systems, which already use higher voltages as needed.)
not even close. I'm not aware of a single vehicle still in production with a 6 volt battery system.
Many kick-start and pull-start engines do not have a specific voltage but may use an alternator wound with a number of different coils to produce different voltages.
….As part of a bank of batteries producing a higher voltage. I haven’t seen any 6v equipment manufactured for any engine based equipment larger than a couple of KW for a very, very long time (mid 1960s). Lower voltage means higher amperage means more weight, more cost, more heat, more failures. Objectively, the world would be a significantly better place if we had fully transitioned to 24v or higher (up to 48v anyway) much sooner than later.
Interestingly, micro-miniaturization has reversed the trend of higher voltage = higher efficiency, at least for computing.
yes, because the underlying cell voltage is much lower than that. Many 6 volt batteries still exist because they are used in series to make the desired voltage. They are easier to move around and transport when they aren't build as all the cells in one unit.
But don't 12V lead-acid batteries have a wide voltage range between charged (~14.5V) and discharged (~10V)? I don't think they would provide exactly 12.6V very often, or for very long.
The adjective form of nouns that refer to animals is usually singular when acting as adjectives (goose liver, dog food, rat race). So, it would be two horse asses. The preference for singular is likely to avoid confusion with the possessive form, which in this case would be missing an apostrophe or of for possession: two horses' asses or the asses of [those (specific / in context)] two horses.
The filaments will run off either AC or DC because they're basically just heaters. AC became the norm in mains-powered devices after electrification took off, but a lot of the early radios were powered by DC from batteries - initially this was seperate, possibly rechargable, low voltage battery for the filament supply and a disposable high-voltage battery, with the second battery being replaced by step-up devices using vibrators and transformers fairly early on.
"encouraging unrest in politically sensitive climates" - La Résistance in Vichy France would fall under this. In some countries asking for fair and democratic elections would fall under this.
Or one could say that oppression advances by one funeral at a time. It is not like there haven't been examples of societies changing towards more totalitarian and oppressive over time.
I find it shocking how common this line of tough is now. Maybe the world dreamed about by people who actively celebrate the deaths of those who don't agree with them, is not such an utopia as we like to believe.
My guess would be that historically 6.3V supplies made forvacumee tubes where commonly available when transistor based electronics where created so it made sense to utilize them. Works quite nicely for the typical 5V circuits as a "rough" input voltage to be feed through a LDO regulator, for example. And so it just stuck.