About Me

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I previously worked on Virtual Reality and other hardware at Valve.  I currently work at Google[x].

Prior to starting at Valve, I built computer peripherals such as keyboards, mice, and joysticks that were designed to be used inside MRI machines.  My company, Mag Design and Engineering, sold these devices directly to researchers at academic institutions who used them to publish scientific papers in peer-reviewed journals.

After work, I spend time on many different types of projects that usually involve circuit design, machining, material selection, and general fabrication/hacking.  My favorite place to be is my home workshop.

ben dot krasnow at gmail

http://www.youtube.com/user/bkraz333

http://www.linkedin.com/pub/ben-krasnow/4/6a9/679

http://www.twitter.com/BenKrasnow

Monday, August 20, 2012

First test with 4.8KJ xenon flash lamp (Speedotron 4803 strobe light)

This video shows my entry into the world of high-intensity flash tubes. I was inspired by the work done by the famous Doc Edgerton who built a strobe system for nighttime aerial photography. I've heard the biggest system he built was somewhere between 50 and 75 KJ per flash -- the power needed to illuminate the ground from 1000 feet in the air!

The system in this video is a Speedotron 4803, which delivers up to 4800J per flash. Photographers use the units watt-seconds (Ws) to describe the energy in each flash, which are the same as Joules. I plan to add capacitance to the bank in order to increase the total discharge power, but the voltage may also need to be adjusted since the higher power flashes also tend to require higher voltages. I'm also planning to try different xenon flash tubes, which are capable of more intense flashes.

Monday, August 13, 2012

Decapping ICs (removing epoxy packaging from chips to expose the dies)

I thought it would be interesting to try decapping some chips. This involves using fuming nitric acid, which also seemed fun, so I thought I would give it a go. The process starts by milling a precise pocket into the IC using my CNC machine. I used carbide tooling to cut the glass fiber/epoxy material. I then put a drop or two of the acid into the pocket, and raised the temperature to about 100*C. The acid dissolves the epoxy packaging as it sort of "dries". I added more acid to the pocket every few minutes. After about 10 minutes, I washed the IC in acetone, then reapplied acid if there was still material left on the die. Eventually, it was all cleared away, and I had a nice decapped IC.

Monday, August 6, 2012

Tour of Ben's shop 2012



Some people were curious about what my shop looks like, so here is a video tour. It seems that I was really rambling, since this video turned out much longer than expected.