Love from The University of Chalmers! Thats me, because when you pronounce Love differently you get my Swedish name.
Now and then I'm working on a project as a student, and I would like to share some of them with the rest of the world.
Apart from what could be expected, the blog won't be designated to mechatronic systems exclusively.
Hope you find something of interest.
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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].
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 http://solarvan.co.uk/savonius)
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…
I got my hands on an HCM65R guitar amplifier. It's an okay amp I guess, if anything it's loud enough to rise a mob against you even if you live off in a rural area. But, something that's been bothering me and many fellow reviewers it is that it lacks distortion. For me it's usually enough for blues but some palm muted metal, like Into the void with Black Sabbath, comes out a bit soft.
As both of the volumeknobs were broken I took the amplifier apart and started thinking about a way how to get this loudly purring kitty to growl like a beast. When taking it apart I saw that the PCB is really old school with large components placed with a lot of space between them. So, hack friendly! I found out what to change and how, tried and it worked. Check the video below to hear how different it got.
I play some random stuff with and without the modification and I think that the difference in tone is very clear.
How to do it
This is for you who knows how to solder and…