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.
This circuit is from a 1980s Motorola documentation. The circuit can be set to fire from 60 to 120...
This amplifier was found in an old publication of 1990. With the changes, it may still be...
In the figure we have a very low current DC to DC converter using a 555. The circuit can have...