Gamma Radiation detector using a PIN diode and a Maxim MAX4477 ultra low noise op amp... Gamma-Photon Radiation Detector - Application Note When a single gamma photon with sufficient energy strikes the PIN Photodiode in this circuit, the output of the comparator pulses high.
When you think of a radiation detector, you’re probably thinking of a Geiger tube and its high voltage circuitry. That isn’t the only way to measure gamma radiation, though, and [Alan] has a great circuit to measure even relatively weak radiation sources. It uses a very small photodiode, and draws so little power it’s perfect for projects with the smallest power budgets.
uP App Note: Measuring processor Vdd by using ADC to measure internal fixed voltage reference voltage. Specifically for PIC with FVR modules and in this case example uses 18F25K22 , but would work for many (but not all) other processors. | Works by using ADC with Vdd based reference and thus a ratiometric result linked to Vdd, to measure a known fixed reference.