Wednesday, September 30, 2009

Image of the Day: Mercury

This image of Mercury was taken yesterday, September 29th, 2009.

credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Here was Messenger flying past Earth in 2005:

And Mercury transiting across the face of the Sun from Earth:

Thursday, September 24, 2009

Geiger counter current draw

This circuit connected to my geiger counter uses on average 80uA-- that's 0.08mA. On a click, it will bump up to 0.1mA. On startup just for a second it uses 3mA. At those rates, and with a standard 9V battery (at 650mAh), it would run about 9 months continously.

Saturday, September 12, 2009

Geiger counter offline

I've been having serial port problems with my geiger counter that has been running since December 1st, 2005, and so at the moment there is no reading.