Found in the July 1994 Electronics Now magazine, this circuit drives a relay up to 12 V depending on the power supply. The transistor can be general purpose.
The configuration shown is from the National Semiconductor Linear Applications Handbook. The...
Found in a 1970 American publication, this circuit uses transistors of the time. These transistors...
This flasher with a small incandescent lamp was obtained in a documentation from the 80's. The...