This filter was found in a Texas Instruments manual based on an operational amplifier 741. Other operational can be used and, with the indicated components, the rejection frequency is 2 kHz.
This simple calibration circuit consists of a crystal oscillator that generates an accurate 100 kHz...
This circuit produces a low frequency magnetic field used in old inductive remote controls with a...
We found this circuit in a European publication from the 1970s. The transistor is made of...