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.
Here is a very simple robot circuit that follows the line driven by a small 3 V sevomotor that...
This circuit, which provides a power of up to 3.5 W, can be supplied with voltages from 9 to 14 V....
This circuit transmits the signal taken from a telephone line to a receiver placed nearby (up to a...