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




Monday, October 29, 2012

Reverse-engineering and testing an x-ray filament supply

I bought a set of x-ray equipment on eBay, which included an x-ray head unit, 50KV supply, and filament power supply. The filament supply has a 25-pin connector, and no data or markings on the case or board. I spent some time reverse-engineering the circuit, and determined how it should be connected to make an emission-controlled x-ray system. I tested the whole thing, and it appears to be working as intended at 50KV / 1 mA.  The head unit produces a beam of about 25 degrees total angle.

Monday, October 15, 2012

Turning a laminated wooden vase on the lathe

I've made a series of wooden vases and similar items by laminating contrasting boards, then turning them on the lathe. I like to use walnut, maple and either bloodwood or padauk to create a white/black/red theme. I almost never use stains, instead I just finish the wood with clear wipe-on polyurethane, using two coats for a fairly matte finish.

Sunday, October 14, 2012

Measuring the voltage, current, and light output of a strobe flash lamp (Speedotron 4803)

I wired up a high-power photography strobe light to my oscilloscope and made some measurements of the input voltage, current and light output.