We found this circuit in volume 5 of the 1995 Encyclopedia of Electronic Circuits. It fires a high-power pulsating xenon light.
An advanced motor control software plug-in for Microchip’s MPLAB® X Integrated Development...
This relay without lock uses a general-purpose transistor. The relay is according to the supply....
This signal follower is from a 1970's documentation. So it uses the traditional configuration at the time...