Found in a 1992 book, this circuit is intended for operation with audio signals. Equivalent operational amplifiers can be used. The optical coupler is an unusual type today.
This circuit can be used in physics experiments, in ionization and in several other applications. The...
Through digital control, this circuit activates the input filters that have the frequencies...
This VCO or Voltage Controlled Oscillator uses common components. The circuit generates signals that...