This circuit is from the time when cars used contact breakers. This 80's version measures the dwell angle of the contact breaker for dwell adjustment using an era integrated circuit, the LM3917.
Yes, tunnel diodes can also be used in voltage regulators, as shown in this circuit from a Radio...
Using a 555 this circuit was found in old documentation, but it is still valid. | Clique na imagem...
According to the author of this project, from a documentation on espionage from the 1980s, this...