This interesting 1924 triode tube receiver was found in a documentation by Gernsback. Observe supply voltages. Coils are for tuned wavebands.
Combined with the two previous circuits, we can create a simple multimeter with this circuit. The...
This 1.5V instrumentation amplifier was found in National Semiconductor documentation from the...
This simple circuit helps to save incandescent lamps by leaving their filament slightly heated and thus...