This commercial radio for the AM band was sold in Japan in the 1960s. The circuit has an IF of 455 kHz and is powered by batteries. The push-pull output gives a good audio power.
In this circuit from a 1991 publication, we can use the 2N2646 unijunction transistor and the...
In the figure we have the way to use the transistors of an old-paired pair as a trigger circuit. The...
This static switch or electronic contactor was found in a 1968 Motorola publication. The triac...