We found this mixer in an American documentation. Operational amplifier supports equivalent and changed number of inputs. Power can be between 6 and 12 V.
This circuit was found in a 90s Electronic Design. It uses integrated circuits that are not common...
The frequency of this oscillator depends on the crystal used and has a threshold given by the...
This circuit is from a 1993 Italian magazine, but it can be easily assembled today. For 110 V,...