I spent quite a while last week reading a patent entitled “Output Split Electrically-Variable Transmission with Electric Propulsion Using One or Two Motors”. While a poor choice of bedtime reading it is fascinating if you’re interested in how the Chevrolet Volt and its Vauxhall/Opel Ampera siblings actually function. You will probably need an engineering education to understand the patent. Fortunately I have one I prepared earlier.

The revelation that there can be a mechanical connection between engine and drive motor caused quite a stir online, but I think the arguments are mostly nonsense.

I’m not particularly interested in debates about the philosophical difference between plug-in hybrids and range-extended electric vehicles. I’m interested in technology that works, and that improves a vehicle’s overall efficiency in normal daily use. The Volt will very clearly be extremely efficient for regular short commutes, and seems to have a very intelligent setup for those frequent or rare longer journeys, depending on your motoring habits.

I spent the weekend putting together an animation – my first – to try to illustrate how the various components of the Volt’s drivetrain fit together in the car’s various major modes of locomotion – from charging the battery at a standstill through to full-speed REEV mode.

There is one annoying error in the finished video, although it’s not important to the plot, so to speak. Let me know if you spot it.