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 an old documentation from the 70s. Its purpose is to indicate the...
Based on the CA3140 IC, this circuit was found in the June 1986 issue of Radio Electronics....
We found this circuit in documentation from the 1980s. It is an input stage for a digital...