The circuit shown consists of a power stage for relay excitation. 2N3053 can be a BD135 and 2N406 can be replaced with a BD136. R3 depends on the trigger voltage.
The Texas Instruments TPA3100D2 integrated circuit (www.ti.com) consists of an efficient class D...
This circuit was found in an American documentation on transistors from the 60's. The transistor is made...
Found in a Radio Electronics from the 90s, this circuit generates a 1 kHz signal to serve as a...