E)
This circuit uses a reversible double contact relay to obtain the trigger lock with the unijunction pulse. The relay must be of the sensitive type with at least 150 ohms of coil.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...