Author Archives: mathscinotes

Incredible Mechanical Music Player

Posted on 2-March-2014 by mathscinotes

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

Posted on 2-March-2014 by mathscinotes

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

Old School Spacecraft Thermal Insulation

Posted on 28-February-2014 by mathscinotes

Quote of the Day Everything not forbidden is compulsory. — T.H. White, The Book of Merlin. I have heard people make similar statements about quantum mechanics, particle physics, and cosmology. Introduction I saw this article about a solar probe called … Continue reading →

Posted in Astronomy, History of Science and Technology | 1 Comment

Mars Rover Solar Panels Getting Dirty

Posted on 23-February-2014 by mathscinotes

While reading some articles on the Mars rovers, I saw this pair of pictures showing the Opportunity rover's solar panels first deployed in January 2004 and today − its solar panels are now very dirty (Source). There was a time … Continue reading →

Posted in Astronomy | Comments Off on Mars Rover Solar Panels Getting Dirty

Heavy Water Ice Cubes Do Not Float

Posted on 23-February-2014 by mathscinotes

Quote of the Day The problem with object-oriented languages is they’ve got all this implicit environment that they carry around with them. You wanted a banana but what you got was a gorilla holding the banana and the entire jungle. … Continue reading →

Posted in General Science | 14 Comments

Presidential and Civil War Trivia

Posted on 22-February-2014 by mathscinotes

Quote of the Day Pay no attention to what the critics say; There has never been a statue erected to a critic. — Jean Sibelius I like to watch CSPAN's history coverage. During a recent program, I heard an historian … Continue reading →

Posted in Military History | Comments Off on Presidential and Civil War Trivia

Two Napa Valley Winery Tours

Posted on 19-February-2014 by mathscinotes

Quote of the Day The emotion at the point of technical breakthrough is better than wine, women and song put together. - Richard Hamming Introduction I am on a business trip this week to Petaluma, California, and for the first … Continue reading →

Posted in Personal | 2 Comments

Sewer Math

Posted on 15-February-2014 by mathscinotes

Quote of the Day A startup is a temporary organization searching for a repeatable and scalable business model. - Steve Blank Introduction A good friend of mine is an entrepreneur and I caught him doing some math the other day. … Continue reading →

Posted in General Mathematics | 6 Comments

Lead Paint Math

Posted on 12-February-2014 by mathscinotes

I shudder to think of the Romans using lead acetate as a food sweetener. Our use of lead as a gasoline additive, which put lead into the air, was probably not very health either. I saw a blog post where a construction worker was asking about how much lead there is in one square foot of painted wall surface. I thought it would be worthwhile to work this number out. Continue reading →

Posted in General Science, Health | Comments Off on Lead Paint Math

Mathcad Solution to an LVPECL to LVDS Matching Problem

Posted on 11-February-2014 by mathscinotes

Introduction A circuit question walked into my cube the other day. An engineer in another group was working his way through an application note and he found the presentation unclear -- I agreed with him. The application note provided an … Continue reading →

Posted in Electronics | 1 Comment