Today I was at Bauhaus in Uppsala, just browsing, not looking for anything special. Close to the exit there was a table with LED light bulbs which were obviously taken out of the regular assortment and re-labelled with new prices. Usually you would expect a bargain – and since I am somewhat sold to LED… Continue reading special offer at Bauhaus
Category: Everything
Do you need a byte?
My latest Instructable is on the design of a breakout board to view the state of up to eight bits in a breadboard circuit. I don’t fell I have the time to repeat all the steps from the Instructable here, just let me tell you that it works nicely! The circuit itself is simple: the… Continue reading Do you need a byte?
Upgrading a RAID-1 Ubuntu-server
It’s almost 4 years now since I installed my server and I decided it was time for some new (bigger) harddisks. I wrote about my server earlier in my blog, but here is a short summary about its current state before the upgrade: processor AMD Athlon (Barton) 1.3 GHz(?) mainboard Zenith … memory 512 MByte… Continue reading Upgrading a RAID-1 Ubuntu-server
Merry Christmas!
PISA – what’s wrong with Sweden
The Swedish education system used to be a good example, but looking at the new PISA results, Sweden is among the countries with the strongest deterioration in school education in reading, mathematics and science. The only thing Sweden has achieved is to narrow the gap between top and low performers – obviously by lowering the… Continue reading PISA – what’s wrong with Sweden
MOSFETs – what the datasheet doesn’t tell you
I am planning to construct a logarithmic current meter and were yesterday doing some simulations with LTspice. Using a logarithmic converter you can span a wide range of currents with a single readout without the necessity to switch ranges. Of course this has disadvantages as well, but if you know what you are doing it… Continue reading MOSFETs – what the datasheet doesn’t tell you
Pandora’s Promise (The movie)
Yesterday I had the opportunity to watch a screening of the movie Pandora’s Promise at Uppsala University. After the movie there was a panel debate including the director of the film, Robert Stone. Since there was a lot of noise around the movie on the internet I was looking forward to see the film for… Continue reading Pandora’s Promise (The movie)
Repairing a Samsung Syncmaster 913TM
I recently got hold of another broken Samsung monitor. This time it is a Syncmaster 913TM which is characterized by its swiveling stand, which allows the screen to be rotated by 90 degrees. I would not call this “portrait” as opposed to landscape, because of the screen’s almost square aspect ratio of 5:4. Connecting power… Continue reading Repairing a Samsung Syncmaster 913TM
Notes from the student lab
Every place in our course laboratory is equipped with an analog oscillsocpe and a Metex Universal System. This instrument consists of a power supply with two fixed and a variable outpur voltage, a multimeter, a function generator and a frequency counter. This sounds nice and it usually is – most of the time the instrument… Continue reading Notes from the student lab
About filters and cut-off frequencies
A good question was brought up by my students in the lab exercise in the course Electronics I yesterday: What actually makes the cut-off frequency of a filter circuit (1st order) so special? Why do we look out for a point which happens to be located or a factor of under the amplitude of the… Continue reading About filters and cut-off frequencies