Found in Popular Electronics from the 90s, this circuit generates signals in a frequency range set to R7 and basically determined by C1. Operational and equivalent transistors can be used.
We found this circuit in a 1998 publication. The circuit has controls for both frequency and...
This circuit for conventional lines was obtained in a 1996 documentation. The circuit uses common...
This is the conventional version of capacitance multiplier with operational amplifier that appears in...