This operational amplifier circuit with variable gain was obtained in an 80's Electronic Engineering. The circuit applies to other operational amplifiers.
This circuit was found in a 1960s documentation, providing a 2,000 gain amplified output. | Clique na...
Frequency in this oscillator is controlled by a crystal. Any 1 MHz to 15 MHz can be used. The JFET can...
This small source is suitable for low consumption equipment that uses batteries. The circuit is...