Vermes
Advanced Member level 4
Before the alert system, a portable Geiger-Muller counter for measuring beta and gamma radiation on the tube GM SBM-20 was made. The counter was equipped with the system that converts the pulses to the dose equivalent (in uSv/h) and counts per minute or second. Schema and program for the counter can be found here: index.
The same system was used in the alert system. Converter 400V and the GM tube are the most important module in this device. Schema of the converter was found there: **broken link removed**.
A suppressor 1mH and transistor from ATX power supply C3038 were used in this device.
Another module is a system that counts the pulses.
The last module is system alarming with exceeding radiation. It is controlled by Attiny2313. The program was written to count more than 10 pulses within 5 seconds, what starts the alarm (high signal at output 1 and 2Hz signal at output 2 uC). The system should be reset manually to stop alarming.
All the components, except the buzzer, GM tube and power supply were closed in a plastic housing. The probe with the tube is moved on the cable about 2,5m with BNC end, so it can be easily unplugged from the main module. The system during operation takes 70mA, in alarm about 110mA. Power supply is 12VDC. The controls on the housing mean in turn: power, particle counting and alarm.
Link to original thread – KRUK-1 System alarmowania o skażeniach promieniotwórczych