Thursday, December 08, 2016

Potent solvent

Today I discovered that n-butanol can dissolve our chemical-resistant plastic floors.

Tuesday, December 06, 2016


This Saturday I worked on an interesting stoichiometry problem:

How much coolant solution do I need to remove, if I want to replace the same volume of coolant with pure solute to arrive at a specified coolant concentration with the original volume.

It's solution involved simultaneous equations.

I found a plausible solution. Yay!

When I got to the lab today, and measured the actual concentration, it's about 1%. For the precision that I need I might as well just assume that the current concentration is zero and work from there. Simple arithmetic will do the job. As usual.

Tuesday, February 16, 2016


Today I discovered that it's not a good idea to blow liquid superglue out of small holes. It might splatter onto one's face.

Friday, November 07, 2014


Today I discovered that an intermittent short circuit can look a lot like an intermittent open circuit. The difference is that an intermittent open circuit will not burn out components.

Friday, October 24, 2014

Sparks = damage.

Today I discovered why short-circuiting the input side of the robust LM7812 voltage regulator will destroy it.

I've had train wrecks of series of regulators dying from a single short-circuit on the input side of things. This was most unexpected. The cause is the capacitor on the output side trying to push power backward through the regulator. It can be prevented by connecting a diode across the input and output.

Thursday, October 09, 2014

New floor

I've discovered that I need a new kind of floor in my lab. A floor that's like a carpet, so that small objects dropped on it doesn't bounce and roll away, but also a floor that's smooth and shiny, so that I can find small, dropped objects.

Monday, July 22, 2013


Today I discovered that when I set the loop duration to 10 milliseconds, which is a period much to short for the loop to complete its tasks in, the data time interval will reflect the time taken by the computer to complete the loop.