This circuit is from a 1965 Motorola manual. It can be implemented with a common 2N2646 and a 106 Series SCR without problems. The pulse transformer has a 1: 1 turn ratio.
This circuit drives symmetrical loads through a single transistor. The circuit is from a Radio...
The transistors of this circuit can be BC548 for NPN and BD136 for PNP with load up to 500 mA. The...
circuit is used to increase the sensivity of a relay. A 50 to 100 mA relay can be triggered with...