Found in a Popular Electronics from the 90s, this circuit activates a recorder for automatic recording of telephone calls. The circuit was used with old cassette recorders of the time.
This circuit was found in a 90's RF Design. The circuit employs an integrated of the time. The 56 to...
Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and...
This circuit was found in a Popular Electronics of 1993. The operational amplifiers can be the...