Sunday, November 18, 2018

MEMs oscillator sensitivity to helium (helium kills iPhones)



I tested the 32KHz MEMs oscillator used in some phones, and discovered that just a 2% helium environment will cause the oscillator to fail.  I also do a teardown of the MEMs device, and inspect it under the electron microscope.

iFixit blog post: https://ifixit.org/blog/11986/iphones-are-allergic-to-helium/  and vid:  https://www.youtube.com/watch?v=D0YLW6v5hrA


Original thread about MRI facility and iPhone failure on Reddit: https://www.reddit.com/r/sysadmin/comments/9mk2o7/mri_disabled_every_ios_device_in_facility/



MEMs silicon encapsulation:  http://micromachine.stanford.edu/~bongsang/pdf/Candler_2005_Transducers05_Hydrogen_diffusion_encapsulated.pdf

Applied Science on Patreon: https://www.patreon.com/AppliedScience

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:  https://pdfs.semanticscholar.org/7efe/c1a814298b121ecf67947183d3630db7f3b0.pdf

https://www.patreon.com/AppliedScience


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.