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 regulator for switching sources up to 3 A was suggested by the Linear Applications Handbook of...
This circuit provides a high intensity pulsating signal to a speaker. The circuit is from an...
This circuit was obtained in a 1998 publication, but it can be easily assembled. The circuit...