This circuit is from an old Japanese publication of 1962. The circuit uses two batteries, one for the filaments of the tubes and the other one of high voltage for the plate circuits.
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...