I wrote last week about EMF measurements. Here is more information on the DT-1180 2.3″ LCD Screen Electromagnetic Radiation Detector I used for electrical field measurements. DT-1180 2.3″ LCD Screen Electromagnetic Radiation Detector is a meter designed for electric fields and RF field measurements. DT-1180 2.3″ LCD Screen Electromagnetic Radiation Detector measures low frequency electrical →
An electromagnetic field (also EMF or EM field) is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature. EMF measurement →
Yesterday the temperatures were at -28 degrees Celsius in southern Finland. That’s really cold. This is so cold that is starts to cause problems in all sorts of devices. I had problems in starting my car. The battery felt weak. I planned to measure the voltage in it with a multimeter I have in my →
When browsing Dealextreme New Items one day I saw Logic Analyzer w/ DuPont Lines and USB Cable for SCM – Black product that was described as USBEE AX PRO. I had previously looked at the USBee but thought they were too expensive. This one was really cheap (around 10 Euros). I have not tried USBEE →
Every summer we get thunderstorms, with the accompanying lightning. Last summer one ADSL modem and computer Ethernet interface I was using was destroyed by lighting. So I decided that an article on ADSL overvoltage protection would be a good idea. It took some time to get this article ready, but here it is. ADSL overvoltage →
Have you ever wanted to find out how strong a magnet really was, or how the strength of the magnetic field varied as you changed the distance from the magnet. Devices used to measure the local magnetic field are called magnetometers or gaussmeters. There are commercially available meters for this, but they are usually a →
Many laptops are pretty well known for having terrible audio interfaces. There are usually noise and grounding issues. A recent post Yet Another Dell Laptop Audio Grounding Problem blog posting documents a well known and horrendous audio problem found on many Dell laptops. I have faced problems with Dell laptop ground loops. And I have →
Unless you add a measurement instrument to your computer, you have only the sound card as an analog I/O port. You can use the sound card to digitize ac analog voltages but only within a limited range. You can, however, add some signal processing and measure a wider variety of signals, even those that produce →
The idea if replacing fluorescent light bulbs with LEDs seems to become popular. There are different kind of products made for that purpose, some are good and some not so good. So I felt it was now good time to test this technology. LED technology promises to reduce power consumption about 50% of fluorescent bulbs →
For good macro photography you need to have good light. Getting nice light nicely to location near camera lens can be sometimes hard. Some photographers use special Macro Photo Studio. Some macro photographers use two flashes mounted on opposite sides of the lens. Some prefer to use ring lights. After some experimenting I thought that →