This integrated amplifier was found in a non-existent British magazine from 1975. The used integrated circuit is still popular and the mono bridged version can provide 36 W output power. 4 A.
This buzzer with the 555 was suggested by a Popular Electronics from the 90s to be used as a...
This is the receiver for the previous circuit found in the November 1991 Radio Electronics...
In the figure we have the configuration of series regulator protector suggested by Motorola in 1968...