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.
This crystal configuration can be made with triggers of any logic. The frequency is given by the...
This circuit was obtained from an 80s factory manual. The integrated circuits used are uncommon...
We found this circuit in an old American documentation. It is an electronic rheostat with a...