This signal injector and tracer (follower) was found in an old American documentation. The transistors can be general use and power is made with one or two common cells.
We find this efficient emergency lighting system in a 1987 publication. The circuit keeps a...
This circuit was found in old publication from 1958. The circuit uses germanium transistor, common in...
This circuit is in the very datasheet of Texas Instruments that manufactures the component...