A Portable Geiger Counter That Runs for 2000 Hours on a Single AA Battery
A portable, sensitive, low power, analog Geiger counter
An electronician builds a highly sensitive, low-power analog Geiger counter using a large Chinese J306β tube. The circuit runs from a single AA cell for over 2000 hours, draws only 1.1mA at 1.5V, and uses a clever flyback converter with common diodes as voltage references. The author explains the design choices, including why analog beats digital for scanning and how the averaging time adapts to radiation levels.
When it comes to Geiger tubes, size does matter. The larger the tube is, the more counts per minute it will give for a given radiation intensity, simply because of its larger capture area.