This circuit rejects frequencies around 1 kHz and can be adjusted using C1. Equivalent operational amplifiers can be used, and the power supply must be symmetrical.
Found in a Popular Electronics from the 90s, this circuit presents the difficulty of obtaining the...
This circuit is intended for testing small capacitors. What we have is an astable multivibrator, which works...
I found this circuit in a Popular Electronics from November 1999. The magazine is no longer...