Monday, October 8, 2018

Dry water and Burning ice: all about gas hydrates

Two unusual materials with unusual names.  I show how to make "dry" water and propane gas hydrate, which looks like ice and is flammable.

Dry water

Propane clathrate

Propane hydrate formation

Methane storage in hydrates

Propane hydrate:

Propane vapor pressure:

Fumed hydrophobic silica on eBay:

Sunday, August 19, 2018

Vintage electrical tech - Weston Sensitrol Relay

This vintage electrical meter is incredibly sensitive, and latches relay contacts with just 18 nanowatts!

Link to old Weston advertisement from 1950's:

Sunday, August 12, 2018

Engineering magnetics -- practical introduction to BH curve

A practical introduction to understanding magnetic devices such as transformers and motors. This video covers BH curves, reluctance, permeability, DC and AC magnetic circuits, and some applications. 

Please put questions in the comments, and I'll do my best to answer them! I apologize that I didn't mention inductance. 

This video focuses only on the magnetic side of things. Inductance is how the electrical circuit interacts with the magnetics.

Sunday, July 15, 2018

Candle flame is repelled by magnets (and Zeeman follow-up)

Why is a candle flame repelled by magnets? It turns out to be a combination of diamagnetic soot particles and hot gas.

Dr. Faraday on the diamagnetic condition:

On Flame and Gases:

I should have mentioned in the video that the exhaust from a flame will be oxygen-poor, thus also making it more diamagnetic than normal air.  Air is a mixture of nitrogen (diamagnetic) and oxygen (paramagnetic). Removing the oxygen will make the resulting gas more diamagnetic.