Monthly Archives: March 2014

Kepler Planet Finding Probabilities

One of my favorite online magazines is +Plus. I was reading an article in +Plus today about how the Kepler satellite finds exoplanets and the article mentioned a simple formula for the probability of Kepler being able to detect a planet. I thought it would be interesting to discuss this formula here because it involves a simple formula that provides insight into cutting-edge science. Continue reading

Posted in Astronomy | 1 Comment

Discussion of Math Associated with MH370 Search

Here are a couple of web sources on how the course of MH370 was determined. CNN Ars Technica Some of these transponder-based, distance analyses reminds me a bit of the Oboe navigation system used during WW2. The Doppler shift work … Continue reading

Posted in Navigation | Comments Off on Discussion of Math Associated with MH370 Search

6000 Meter Depth Rating on Ocean Search Gear

Quote of the Day The sea is notoriously unforgiving, but it reserves its harshest penalties for those who venture beneath its surface. — U.S. Navy veteran A.J. Hill I have been watching the news coverage of the search for the … Continue reading

Posted in Underwater | 1 Comment

Frost Depth Deeper Than Normal This Winter

Quote of the Day Maybe not today..., maybe not tomorrow..., but someday... soon; ... and for the rest of your life ... - Rick Blaine, Casablanca. I was in my home town of Osseo this weekend to do some computer … Continue reading

Posted in Construction | 1 Comment

Using a D-Size Battery String for a UPS Energy Source

Quote of the Day If there is one thing more than another for which I admire you, it is your original discovery of the Ten Commandments. — Thomas B. Reed to the youthful Theodore Roosevelt about his self-righteousness Introduction I … Continue reading

Posted in Batteries, Electronics | Comments Off on Using a D-Size Battery String for a UPS Energy Source

A Simple Frequency-to-Voltage Converter

Quote of the Day We are what we repeatedly do. Excellence, then, is not an act, but a habit. - Aristotle Introduction I often build small electronics projects for use around my home. I recently put together a small sensor … Continue reading

Posted in Electronics | 41 Comments

Population Occurrence Frequency Math

Quote of the Day Do what you can, with what you have, where you are. — Theodore Roosevelt I was reading an article on autism and the article mentioned that autism is much more prevalent in boys than girls. This … Continue reading

Posted in General Science, Health | Comments Off on Population Occurrence Frequency Math

Paper Mechanism Project I Have to Build

I think this interrupted motion paper machine is really interesting. This is on my list for a project. If you want to see other projects like this, got Robert Ives' web site.

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Incredible Mechanical Music Player

Take a look at this digitally-created instrument and how it is being played.

Posted in Personal, Uncategorized | Comments Off on Incredible Mechanical Music Player

Schmitt Trigger Design Math

I have a home project that requires me to design a Schmitt trigger circuit. There are numerous places on the web where you can find design equations for the Schmitt trigger constructed using an open-drain comparator. Unfortunately, these design equations do not model the output low-level saturation voltage of the comparator and in my application I need to be concerned about this voltage. My objective is to determine formulas for the resistors in the circuit as a function of the various threshold and output voltage levels I require. Continue reading

Posted in Electronics | 14 Comments