This circuit comes from a Gernsback Publications of the 90s. The circuit uses a general-purpose transistor as a sensor. The power supply must be symmetrical.
This filter was found in old Raytheon documentation. The circuit makes use of operationals of the time, but...
This circuit allows to obtain an output pulse independent, in duration, of the action time on...
This preamplifier is indicated for low and high-impedance sources as microphones, transducers,...