Geiger counter

# Geiger counter Geiger tube model SI3BG. This model of Geiger tube is cheap, has a large range and low sensitivity, so the measurement results are for reference only. ## 1. The engineering description schematic and PCB are imported from Altium Designer files, so there may be some problems. The more obvious problems have been corrected. The copper laying of Lichuang EDA will not remove the dead copper. It seems that it needs to be hollowed out manually. If you mind You can view the original file in my [github repository](https://github.com/luckyjkl/geiger-counter). ### 1.1 Reference design Geiger tube measurement circuit design reference [https://oshwhub.com/zhaokbk/si3bg_copy_copy](https://oshwhub.com/zhaokbk/si3bg_copy_copy) Geiger tube power driver part reference [https: //oshwhub.com/zhaokbk/lm3481-gao-xiao-bian-ya-qi-hui-guang-guan-sheng-ya-mu-kuai](https://oshwhub.com/zhaokbk/lm3481-gao-xiao -bian-ya-qi-hui-guang-guan-sheng-ya-mu-kuai) ### 1.2 Notes 1. The OLED screen is installed in the upper left corner. The PCB of the screen will interfere with the copper pillar, so you can only install it The screen PCB was sawed off a little, because the screen has been glued to the acrylic board, so the position cannot be adjusted. If you mind, you can move the screen to the right by yourself. 2. Why is a 5V boost circuit added to power the Geiger tube driver? Can I remove it? Because after actual measurement, to boost the voltage to 400V, the input voltage of the Geiger tube driving part needs to be above 3.8V, otherwise the output cannot reach 400V, and the efficiency of the driving circuit part is higher at higher voltages. When the voltage is reduced, the power consumption will be sharp. Increase, affecting battery life. 3. How to choose the MOS tube model for the boost part? * Choose one with low on-resistance to reduce power consumption. * The secondary side of the coil is boosted to 400V, and the turns ratio is 1:10, so the reverse withstand voltage of the primary MOS tube should be greater than 40V 4. In order to improve the efficiency of the Geiger tube driving part, a 5V booster is added Voltage circuit, the system is not simple enough, you can replace it with a lithium battery charging chip with 5V output to simplify the circuit solution. 5. The interface model of the SWDIO port is SH1.0-4P