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.
Found in Radio Electronics from May 1959, this transistor tester is quite sophisticated. The...
This circuit was found in a 2005 Linear Technology sensor manual. The circuit can function as a shield...
We find this circuit in a 1995 documentation. It warns when the timing is nearing its end, with...