diy

MOSFET testing

Multimeters are very good tools to find out problems in electronics circuits and testing electronics components. Resistor measurement is found in practically all multimeters, capacitance measurement range is becoming more and more common and some high-end models can also measure inductance. Many multimeters have also possiblity to test bipolar transistors (Hfe measurement range), but I

Parallel port still popular

The traditional PC parallel port is getting more and more rare on new PCs. It could be said that the parallel port is practically dissappearing from the PC technology. For example my new PC I use (bought more than year ago) did not have parallel port in it. Started documenting parallel port controlling document Parallel

Easy to use stepper controller IC

I had some stepper motors from old disk drives and other electronics devices lying around. Those were typically designed to be driven with 12V voltage and take few hundred mA of current per phase and had five or six wires (four phase). I thought that it would be a good idea to turn them to

Build Your Own Multitouch Surface Computer

Touch interfaces are hardly futuristic at this point, but multi-touch hardware like the Microsoft Surface or the iPhone is just starting to become a big deal. Now it is time to learn how they work and maybe try to build our own. maximumpc.com site has published an interesting article called “Build Your Own Multitouch Surface

Use an old Nokia charger to power 1W LED

Here is one useful trick I invented when looking around the transformers/power supplies I had. NOKIA ACP-7 Europe Standard Charger (Original) has a specification of 230 V, 50 Hz, 4.8 VA. Output 3.7 V, 355 mA. A normal 1W white LED is driven with 350 mA maximum continuous current and typically 3-3.8V voltage drop over