electronics/misc
Anti-Static
There is a great video about static disipative and static shielding bagies from EEVblog.
Summary: “pink” bags and tubes just prevent static buildup (regular bubble or plastic wrap can generate hundreds or thousands of volts pretty easily just by rubbing; non-conductive foam is pretty nasty too). Silver/metalic baggies actually prevent external discharges or shocks from harming ICs inside. If you use a shielding bag, you still need to make sure all the materials inside will not build up a charge.
Random Number Generators
- Wikipedia overview
- Wikipedia comparison of devices
- Entropy Key: a $50 USB key using avalanche
- noise from two P-N junctions; lots of support and features.
- Overview of cheap avalanche technique: http://web.jfet.org/hw-rng.html
- whirlygig CPLD-based source: http://warmcat.com/_wp/whirlygig-rng/
- a bunch of resources: http://www.cs.berkeley.edu/~daw/rnd/
- more: http://robertnz.net/rng_rep.htm
- one open design (as a shield): http://1010.co.uk/org/notes.html#45
- IEEE article on Intel’s hardware
- basic design on cryogenius.com
Breakdown of the base-emitter junction of a 2N3904 happens at about 6v, accoding to: http://sentex.ca/~mec1995/tutorial/xtor/xtor6/xtor6.html
See also: