This circuit makes use of a special LM195 power transistor not very easy to obtain. The circuit is from the 1994 Linear Applications Handbook by National Semiconductor.
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...