This circuit from a Radio Electronics from October 1965 shows how to obtain the action of an SCR when triggering a relay using two transistors. The relay is according to the circuit supply voltage.
We found this simple shortwave receiver in an Electronics Now from the 1990s. Details of the coil...
We found this circuit in a 90's European schematic. The circuit can be implemented with almost any...
In figure 1 we have an application for NLAS5113, a new device from on Semiconductor...