Using LM3909 integrated circuits, this circuit was found in an American documentation from the 90's. The frequencies can be changed by changing the capacitors.
Found in old documentation, this circuit makes use of amplifiers of the time, uncommon today. Next...
Although quite simple, the usefulness of this circuit is great. It can even mean gains for those...
This circuit converts inductances on two scales into voltages. The circuit was obtained from a...