Monthly Archives: June 2012

Some Empirical Potentiometer Results

Just a note that I have added some empirical test results to the following three posts on potentiometers. "Logarithmic" approximation using Linear pot with shunt resistances Square law circuit Opamp-based circuit  

 
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Cost of Cooling Electronics

Introduction One of my favorite physicists stopped by today and wanted to talk about the cost of cooling electronics. The talk was somewhat mathematical and worth discussing here because the basic math is what a homeowner should do when evaluating … Continue reading

 
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Yet Another Circuit with a "Logarithmic" Characteristic

Introduction While I was looking for different circuits that generate a logarithmic characteristic (voltage, current, or resistance), I stumbled upon a web page that discussed a logarithmic potentiometer approximation using a linear potentiometer with one or two resistors connected to … Continue reading

 
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Wall-Wart Math

I have had some questions recently on the power conversion efficiency of AC power adapters (aka "wall warts"). I think my customers are becoming more concerned about energy costs. The questions that I received focused on how the efficiency of … Continue reading

 
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Product Feature Presentations Using Excel's AutoFilter and VBA

I have to present a lot of data to people, but I find PowerPoint, a corporate workhorse, to be a poor vehicle for presenting data. I am not an acolyte of Tufte -- a famous PowerPoint critic -- I just … Continue reading

 
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