We found this precision circuit in a manual from the 80's. The operational amplifier is of a common type at the time, and equivalents can be tested. Transistors are general purpose types.
We found this circuit in the National Semiconductor FETDatabook of 1977. The signal has an...
This circuit was obtained from an English magazine from 1979, but it can be easily assembled today...
September 2016 - Mouser Electgronics already has in stock the new moisture digital sensor HDC1010...