This small tube amplifier appeared in Radio Electronics magazine in February 1958. The circuit is powered by the mains with a power transformer and output with different impedances.
This circuit is from the SGS manual of linear integrated circuits of 1982. The L78xx is equivalent to...
This low displacement circuit was found in American documentation from the 90s. Operational...
The purpose of this circuit is to maintain the liquid level of a reservoir between two values...