Smokie the Inverter Revealed *amended*

Now that’s it’s all fixed, I don’t mind looking at pictures of the scorched components inside the inverter.  It would be more informative if I could explain exactly what went wrong but since I haven’t been told what that is, the pictures only serve to satisfy those with a morbid fascination with charred electronic components.

Four components needed to be replaced:

  • DC-DC converter board
  • High voltage DC input filter
  • High voltage input fuse for dc/dc converter
  • Internal power supply board

The show starts with burn marks on the inverter casing, the first sign that this wasn’t going to be a simple repair.  The other sign was the perfectly fine fuse right next to the blown components, meaning that this wasn’t an amp overload event but something not even foreseen.

It’s hard to tell what exactly went first.  When I find out I’ll post.

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Velomobile Progress and Inverter Update

A trio of 451mm wheels and several piles of folded sheet metal and machined parts have accumulated in piles around the place as I anxiously await the frame to arrive.  I’ve been hesitant to release too many  details as the design evolved since it seemed to only encourage more confusion than clarity (have you ever tried to explain what a velomobile is to the unfamiliar in the first place?) but since the prototype is being built up this is a good time for a summary.

But first, here’s a picture of the chassis CAD model.

Velomobile chassis

The structure is made from a bamboo plywood/balsa core sandwich structure which, once hot-press laminated, is cut out by a CNC router.  No tooling, no welding, no coping of strangely angled tubes.

All three wheels are independently suspended, which sounds like a great idea until it comes time to buy three mountain bike shocks at retail price that, pound for pound, must be more expensive than Formula 1 Konis.  They don’t cost nearly that much to OEMs, which I’ll take advantage of next round.

One of the features I’m most proud of is the tilting mechanism.  The front shocks are connected to a linkage that allows the rider to control the tilt of the vehicle independently of steering angle.  Steering is reacted trhough the rear wheel, freeing up room at the front of the vehicle and allowing a much tighter turning circle than if the front wheels turned.

Since the electronic transmission idea got shelved (a story for another time) I looked for a system that would allow a wide speed range, could be shifted at rest and had enough speeds that the desired cadence could be dialed in perfectly.  The closest mechanical analog turned out to be a NuVinci CVT combined with a Shlumpf MountainDrive, which give an overall gear range of more than 6.

In other news, Smokey the inverter has been nursed back to health and will be heading stateside in only a few days!

Posted in EVs, Velomobiles & HPVs | 1 Comment

A Running Costs Comparison: EV vs. ICE

To illustrate how much cheaper an electric vehicle is to run in comparison to a gas car, I ran some numbers:

How far your $1 goes:
$1 buys about 1/3 of a gallon of gas
If your car gets 30mpg, $1 will get you 10 miles.

$1 can also buy 6 kWh of electricity, assuming you pay about $.15/kWh
A typical electric car uses .25 kWh per mile
So, $1 of electricity allows you to travel 24 miles

That’s nearly 2.5 times as far!  And that’s being generous with the gasoline cost and mpg numbers…

The simpler machine to get you around also allows you to forget about:

Oil & Filter changes

Head gaskets

Exhaust systems

Increased brake wear
Catalytic converters
emissions testing
Fuel pumps
Oil leaks
Gas smells
Rough shifting
Cold starting problems
Spark plugs
…and about 100 other things…

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