Thursday, April 14, 2011

Superspeed USB 3.0 Plugfest in Portland, Oregon

This week I attended the Superspeed USB 3.0 PlugFest at the Embassy Suites in Downtown Portland, Oregon.  Tektronix is headquartered in Beaverton (not far away), so it was a chance to visit the factory and also to learn more about the latest high speed computer serial bus.

So what is SuperSpeed USB? 

Thursday, April 7, 2011

Batteries from Lemons - A Homeschool Electricity Lesson

I have been running a science class for a group of homeschool kids, and of course, most of our science focus is on electricity and electronics as you might imagine.  Last time we did an examination of conductors, insulators, and resistors.  We tested paper plates and metal plates, glass goblets and silver goblets, plastic forks and steel forks, and found that a pencil contains a conductor, insulator, and resistor (wood, metal band, graphite).  This week I wanted to teach them about electricity, specifically that everything contains electrons, but that electricity was really the flow of electrons.  To demonstrate the flow of electrons, we made a battery out of a lemon!

Sunday, April 3, 2011

Using a Counter to Augment an Oscilloscope's Measurements

I made this video to demonstrate how a Frequency Counter can be used to augment the measurement system on an oscilloscope.  In this case, I need an exact count of the number of pulses in a 1 second period.  I use the Totalize function on a Tektronix FCA3120 to count the dropped pulses produced from a Tektronix AFG3252 function generator.  As you can see, the deep memory Tektronix MSO4104B oscilloscope can measure quite a few pulses with 20M of memory, but nowhere near a continuous 1 second or longer period.  In this case, the frequency counter is the ideal tool.

One technical note--although Frequency Counters are available up to 40GHz in bandwidth, various techniques are used for making this measurement that would miss a single dropped pulse.  The Totalize function is limited to about 160MHz, or pulses that are about 2ns wide.