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Profile for uwezi

almost free – still too expensive?

Sorry, this entry is only available in German.

The customer is always right…

…sorry German language only

A fluxgate magnetometer – a prestudy

Just a few days ago I read up about variations in the magnetic field of earth and how these can be used to detect northern lights. Since there have been sightings of northern lights quite recently even in major parts of Germany I became interested in the topic.

A common type of magnetometer is […]

Continue reading A fluxgate magnetometer – a prestudy

…another watt saved…

A few days ago I posted my driver prototype for a 20 W, 700 mA, 32 V white LED. Under best conditions I reached 85% of power conversion efficiency between the 12 V input and the electrical power delivered to the LED. I was not satisfied and one of my suspicions were substantial losses in the power MOSFET.

[…]

Continue reading …another watt saved…

Teaching an old bug new tricks

The 78S40 is not one of the most modern switching regulators, together with its small brother the MC34063 it dates back to the 1990’s. It differs from the 34063 by having an additional, uncommitted operational amplifier inside its 16-pin package. There are many application notes available, since both chips are manufactured by several companies. […]

Continue reading Teaching an old bug new tricks

Do they know what they do?

LED driver

As you can read in my earlier posts I have become quite attached to the AVR microcontrollers from Atmel. We also use these microcontrollers in projects with our students at Uppsala University.

Probably one of the widest spread development tools for AVR controllers is the original STK500 starter kit from Atmel, which in principle […]

Continue reading Do they know what they do?

The new Digikey catalog is here!

2011 Digikey's new catalog

Today I got the new Digikey catalog delivered at the university. It must be the season, during recent weeks also Elfa (you remember: the company which delivers cable by the metre…) and RS-Components have mailed their new paper catalogs.

I still prefer paper catalogs in spite of their environmental impact, because there is simply […]

Continue reading The new Digikey catalog is here!

Troubleshooting against all odds II

semi-conducting wire

The hot wire mystery

I like to build my prototype electronic circuits on perf- or stripboard after having tested it on a breadboard. Actually I would have loved to have breadboards around when I started with electronics some 25 years ago, but it was not before the late 1990s that I got familiar with […]

Continue reading Troubleshooting against all odds II

Troubleshooting against all odds I

Sub-D 25 female connector

The parallel port mystery

Sub-D 25 female connector

Have you ever used or considered using the parallel port of your computer to control your own electronics project?

Well, I have, and this was not my first project. But this time I ran into trouble…

With modern versions of Windows it is not […]

Continue reading Troubleshooting against all odds I

LEDs for Christmas

Sorry, this entry is only available in Svenska.