The DC-DC converter and why it wastes a lot of energy.
Last week I ranted about the energy wasting of Elon Musk's 'gadgets'.
Now it is time to make it visual, and a glimpse into the genius of Nikola Tesla's work. not going to try to explain Nikola Tesla's in detail but doing an attempt to explain to normal people how Nikola Tesla is different then simpleminded Musk LEGO style mindless mass production
It is all about the DC-DC converter.
And that's actually an invention derived of Nicola Tesla's coil and capacitor circuits, heavily miniaturized and cutting corners to produce them as cheap as possible.
What is a DC-DC converter?
In it's basic form it is a coil that get's charged with DC current, then discharged, and the energy gets dumped into a capacitor. Bu doin that at a very high speed it 'appears' as DC current on the output again.
That can be done in several different styles and depending on what works best for a given application will be used in the final circuit.
Just typical electronics design rules.
These four topologies are the 'political correct' depictions of how an industrial electric engineer may apply the components and call it a DC-DC converter as only these topologies have the least 'unwanted side effects' or at least the industry has way to keep the side effects under control by shorting out the side effects (resulting in more losses, but lets not go there in this article...)
The main idea is that the input voltage is different then the output voltage with the least amount of component costs.
Under optimum conditions a industry standard DC-DC converter will be 95% efficient at best. But as a car is not operating under ideal conditions the number will less glorious.
How Elon Musk uses these circuit in his cars.
And here I will also include the Tesla power wall, going from sun rays, fossil and nuclear fuels all the way to usable energy that makes the wheels turn.
First we have the solar panel.
Solar panels are not very efficient themselves only 20% of the sun's energy that hits the panel is converted into electronic pixies.
About 1.2 Volt will trickle out of them at currents that depend on the type of panel
And Elon Musk adds a power wall to that.
This power wall is just a box of expensive batteries and a DC converter that lifts the 1.2 Volt to the voltage of the battery, lets say 2.4 Volt
So after the losses of the cables that are usually longer then 'ideal' the pixies arrive at the input of the DC converter from the power wall.
and here we loose lets say 10%
Then we have, wind, fossil fuels and nuclear energy.
This arrives in your home at whatever AC voltage your country uses for the wall sockets. And that will be brought to the system with yet another lossy AC-DC converter of some kind. I really try to keep things simple for non technical readers and I hope I have not lost them already
Again 10% loss will not be that strange of a number.
Then the power wall
The pixies in the power wall will need to be dumped into the Musk-Mobile
Speed is here the important factor. So Efficiency is secondary, after all you want to use that bling ride on demand to display that EGO that just invested like crazy in this lossy enterprise.
Lets say another 10% losses to get the pixies on the road.
To the Musk-Mobile lets go!
SILENT VROOM!!!
Now the pixies arrive in the car at high velocity and need to be dumped into another set of batteries. so to be able to charge the levels must be at the correct voltage again. and for that we use ... A lossy DC converter. And we loose about 10% again.
Now all that energy is sitting in the batteries, under less then ideal temperatures and temperature fluctuations. And that also can result into losses. Let's leave these out of the equation for now as I don't know how high these are. I'm merely looking at the converters.
Then we need Electro Motive Force, DC current to push the car though the air. At least the Musk-Mobiles are a bit streamlined as the DC converters will add another 10% of losses.
The Musk Mobile also has lights windscreen wipers, electric windows and and an in car entertainment section that will not be very efficient either. But less significant then the motors. So lets also leave these losses for granted.
Most readers will have done the math between the ears already.
If we are lucky then 50% of the expensive pixies will be converted to actual movement from A to B all the rest will be global warming. As losses in electronics are always turned into heat.
That's why DC-DC converters have rather big aluminium heat sinks. The more pixies flow the more heat will be radiating.
50% is lost in DC converters alone.
If Musk had really had the slightest idea about Nikola Tesla's work then he would not have used so many wasteful circuits
Now to be fair, other e-transporters have the same issues.
But Musk's cars are the ones that most people have in mind when they think about e-transporters.
Nikola Tesla
The genius of Nikola Tesla lies in the fact that he managed to create a wireless energy system that worked over long distance. And people who play with the technology know that resonance can have exiting side effects that can result in a higher energy output then what the have put in. Effectively extracting energy from the environment without generating heat.
Let's keep it at that for now. While I think what I can write about next.
I'm not going to be a specialist here. But only tough on the basics and hope that real specialists join in and go into the details.
People need to know the basics if we ever want to be smart about electricity.