September 7, 2017
— updated January 20, 2022
Thermoacoustic fridges are magic: you heat one end, and the other end gets cold. (Of course you have to sink all that heat from the middle.) They can easily be made long and skinny, and so are a natural for use down drillholes. They’re also made entirely of metal, and have no moving parts, so they will survive bouncing around in the back of a truck.
This was a design study for a general purpose fridge for 2-inch cased holes (38 mm maximum OD) that would solve many of the temperature problems of downhole operation for a wide variety of sensors.
Read more…September 7, 2017
This was a photon budget for an OCT system—interesting primarily for the effect of path delay in turning FM noise in the superluminescent diode (SLD) into AM noise in the measurement.
Read more…September 7, 2017
I chaired a series of formal design reviews for a start-up company making immersive displays with resolution better than the human eye.
Read more…September 7, 2017
Another Della project for the Navy: I did a photon budget that showed that this could be done optically within the power and weight constraints, and would work in bright sun as well as at night. (Optical communications are much harder to intercept or to jam than radio.)
Read more…September 7, 2017
— updated January 20, 2022
A shootout between the two major classes of transimpedance amplifier (TIA) designs for one difficult corner of the design space.
Read more…