This 1924 receiver uses a battery for the tube filaments and a high voltage battery for the amplifier and detector circuit. The speaker is kind of high impedance era.
Found in old documentation for radio amateurs, this circuit is intended to excite a MOSFET on the...
The lie detector we presented was created by a professional detective and found in a 1982...
This circuit allows to obtain an output pulse independent, in duration, of the action time on...