The Electronics section of Changpuak maintained by a Teacher of Thailand, Alexander C. Frank, has calculation tools for electronic circuits as well as some electronic projects like power supplies, signal generators and curve tracers too .
Among others they also have Amplifier Design, Antenna and Filter Designer AF and RF and Basic Electronics Tutors.
Homebrew Projects - Laboratory of Changpuak
A Geiger–Müller tube consists of a tube filled with a low-pressure (~0.1 Atm) inert gas. (Helium, Neon, Argon,...). The GM-Tube has a coaxial shape, where the inner conductor (Anode) is biased with a high voltage (~500V) relative to the outer conductor (Cathode). The Tube has a window (left side) made of mica.
This GM-Counter is build on 2 PCB's. One is a standard high Voltage generating circuit, whilst the second is a Counter based on an ATMega16™ which also handles serial Communication with a host (Environmental Control).
Homebrew Geiger Müller Counter
This website conserves all those nifty little mini-projects (gadgets) which were developed to enhance the doctoral hats of our "fresh" doctors.
Doctoral hat electronics - After seeing this section i am convinced that the next innovation will be "SmartHat". There is ample space in a cap for an Advanced Android Multimedia Gadget with a Hepta Core ARM chip and all the works. Rush to the patent office !