This circuit, which can act as a shield, was found in a 1990 PE Hobbyst Handbook. The circuit generates logic pulses for different types of applications.
This circuit using an operational amplifier was found in old American documentation. It can be...
If the circuit oscillates, emitting sound, it is because the transistor is good. This simple...
Like the previous circuit, this is used in the analog part of the telephone lines. The same...