This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the NF type and the transistors admit equivalents. R4 depends on the drive voltage.
This circuit was originally designed to measure capacitance with an ICL7107 but can be used with...
This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an...
A voltage of 13.5V with a current of up to 5 A can be obtained with this high current regulator stage...