This 12 V x 2 A regulator was found in 1965 Delco Radio documentation. The circuit uses transistors from that time. The input voltage can vary by 15% around the indicated value.
This alarm, from a 1996 magazine, can be fitted with two BC548s in the original configuration...
Using only one general purpose transistor this circuit is powered by batteries. The lamp of the...
Can be used as a shield, this old American documentation circuit offers digitally selected...