This circuit is from American documentation from 1970. It can be designed with a BC558 and for the operational, we can use equivalents. The FET can be the BF245.
This circuit uses a simple power source, having been found in the Philips Databook of 1990....
This circuit is suggested by Texas Instruments in its Linear Circuits Applications. It is a...
This circuit generates a pulsed tone whose frequency depends on C2 and whose flashing depends on...