This high-Q low-pass filter was found in the October 1990 issue of Radio Electronics magazine. The frequency depends on the capacitors used and is on the order of a few tens of hertz.
We found this circuit in a 1975 publication. The power supply must be symmetrical, but other...
This circuit is from 1977 documentation, and high current equivalent transistor must be used. The...
Although indicated in the original publication of the 1980s as a capacitance switch, the circuit...