This interesting 1924 triode tube receiver was found in a documentation by Gernsback. Observe supply voltages. Coils are for tuned wavebands.
This circuit triggers a relay when a pulse of light hits the LDR. The potentiometer serves as a...
In the figure we have the way to implement a NO OR or NOR gate with an operational amplifier. The...
The presented circuit is used to test ordinary fluorescent lamps. This circuit also has a mains...