High resolution picture of remote focus control box

By request...

Water vortex display from SJ City Hall exhibition -- repair and upgrade

I built this project a few years ago with a friend to help get him interested in mechanical design. Later, the project was adapted for display at a "tech and art" exhibition at San Jose City Hall. After 8 months, the painted steel impeller began to rust and discolor the water in the tube. I took the device back to my shop and replaced the original aluminum shaft with a stainless steel shaft, replaced the shaft seal, and changed the impeller to an all-plastic design. If I were designing the device again, I would opt for a spring-loaded PTFE (Teflon) shaft seal, which I have used with great success in other applications.

Drill motor control:
http://www.youtube.com/watch?v=7yEABsNyRfo

Original video showing the WiFi-controlled watering can and vortex tube:
http://www.youtube.com/watch?v=XKrlRJ-GJms

Repairing the 5V output from a Mastech HY3005D-3 (cheap import) power supply

The 5V fixed output on my Shenzhen Mastech HY3005D-3 power supply died the other day, and so I took the device apart to investigate. The 5V regulator board had a bad solder joint where the bridge rectifier attaches to the PCB. I used a soldering gun to reflow the joints, and all seems good.

Transcranial Magnetic Stimulation project - part 2

I achieved neuronal stimulation of my primary motor cortex by using a single 15-turn coil and 1700 volt charge on the capacitor bank of about 190uF. The exact position of the coil on my scalp makes a very big difference in how much stimulation is achieved in the motor cortex. I would have suspected the single coil would produce much more diffuse stimulation and positioning would not be so critical. I never got any decent neuronal stimulation with the butterfly coil.

Cooking with thermite

I ignited four pounds of thermite made with aluminum / iron (III) oxide in a flower pot. The thermite reaction quickly formed liquid iron which dripped down out of the pot, and into a ceramic pan. I put a beef kebab directly onto the liquid iron, which cooked the food in under a minute. It was delicious!