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To develop mechatronic and electronic system you need tools and materials, knowledge and loads of persistence.  
While the development and design process can be quite time consuming it's probably the part when getting it to work in practice that steals most of the time and there I am right now. 

A new completely analog ignition circuit for debugging purposes

The bike started a few times during earlier attempts with my ignition system, so the bike hardware seem to do its part. However it didn’t run for more than a few seconds each time it started on that occasion.
During that time I timed the spark in relation to the zero crossings from the AC generator, so no external sensor was needed. However, phase shift from the generator was occurring especially during the critical start RPM’s which moved the zero crossing nonlinearly. That made it hard to actually know the position of the engine.
 When I got it to start I was just having luck with the values I choose on an ignition curve in the software.
Therefore I decided it would be better to first get it to start and run cleanly with a more simple approach and then continue later with the first sensorless approach.

That’s when I added the hall switch mentioned in the post before. It made flywheel positioning simple but consumes grotesque 7 mA of current. My half wave rectifier voltage supply part on the ignition circuit isn’t designed for that.Adding a battery is such a hassle, so yesterday I designed a new completely analog circuit for sort of debugging purposes.
 For some reason though, the spark is now a lot weaker than on my previous system and today I will try to figure out why. Updates will keep coming. 


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[VAWT] Affordable wind measurements

The shop Clas Ohlsson in Sweden sells a spare anemometer for the  WH-1080 weather station for a hobbyist friendly price around 15 euros. This anemometer can probably be found in other countries too.

The WH-1080 spare anemometer

Here  you can read about how to use this anemometer together with an Arduino or any other embedded system.  As we couldn't find any data on the characteristics of this sensor, we did our own calibration in a wind tunnel and the results are presented in the report above. This anemometer was used in a Bachelors Thesis project related to the devlopment of optimization of the Savonius Turbine, here tagged [VAWT].

[VAWT] Plausible improvements of the Savonius windmill

Cut a barrel in half, mount it on a shaft and you have a windturbine. If the barrel is used, then what else probably would end up on a scrap heap is instead used for converting renewable energy.

Simplicity and low cost makes this an attractive option especially for societies with limited economy and a malfunctioning or non existing electric grid. Small off-grid electrical networks can be built and people who perhaps most needs electricity get that. Isn't that neat?

Savonius (from

An overlooked potential?
The Savonius though has a widespread reputation of having low effiency and is often dismissed as a credible option around forums and in formal litterature. However, when looking at the graph below from a publication Wortman did 1983, the effiency can be realtively high provided that the TSR(Tip-to-Wind-Speed-Ratio) is held at a correct value and the windmill should work quite nicely. In practice this could probably be done by controlling the generato…

[RR] Automated rescue boat

We have a project course at our  master program System, Control and Mechatronics, were we could apply to one of around 30 projects available. I was really happy that I got my first choice, which is a project carried out as a joint effort between SSRS (Swedish Sea Rescue Society) and Chalmers. The goal is to develop  autonomous or/and semi-autonomous vehicles that can help out in rescue missions. The current vehicle, a large water scooter named Rescue Runner, is able to follow a larger leader boat.

However, the people involved want some better tracking capabilities and stability of the control system. We are currently a team of three persons hoping to achieve this. Stay tuned, more information will be posted when we finish. Or well, not if we sink though. Then I'll try to cover it up, and hope for dedicated readers to spam me with comments ;)

Here you can read some in Swedish about the project: