Current Events

How to use the [S]cale command

Like many of us, I find it more difficult to wrap my head around logarithmic values than linear values. This makes the [S]cale command on the ee203 very seductive. It outputs the measured current on a linear rather than logarithmic scale. Unfortunately, seductive is not always practical (see, for example, women). A linear scale may or may not be useful to you. Let me explain. One of the things that makes the ee203 such a useful device is its huge dynamic range. 6 orders of magnitude is pretty amazing for such an inexpensive device. Practically speaking the only way to...


Cuba Trip

Not technical or related to our products in any way, but I know that Cuba fascinates lots of people, so I thought I would post a video. This is a time-lapse of a drive through Havana in July of 2017. The route is from Havana Vieja (Old Havana) then along the Malacon (Seawall). You can see the US Embassy on the left shortly at around 0:15. As you can see, there are still a lot of 50's era American cars plying the road, although they are becoming fewer in number as more modern cars are imported.


Operating the ee203 RTCM out of spec

The ee203 specifications show guaranteed values for the normal operating range of 1.5V to 5.5V. However, there is also an absolute maximum rating of 12V. This causes some confusion about whether the unit can be used outside of the range of 1.5 - 5.5V.   The short answer is yes, but performance has not been characterized and is not guaranteed to meet specs. The lower voltage limit is around 0.5V with the upper limit constrained by the internal power supply to about 8V, although your mileage may vary somewhat due to manufactuing tolerances. The absolute maximum of 12V means that...


Calibrating the ee203 RTCM

The ee203 RTCM provides a self-calibration facility to maintain its performance over temperature and voltage variations. The simplified block diagram below shows the on-board current sink that can sink a calibrated amount of current from the DUT terminal. The current sink is accurate to 2%, and has selectable values of 100 mA, 1 mA, 10 uA, and off. The [C]alibration command uses the current sink to generate two data points and then interpolates (and extrapolates) from those points in normal operation. The ee203 has two sensing ranges, one above and one below 1 mA. This two point calibration operation is...