This circuit was found in an ancient American documentation. The power supply is not given, but we have the voltages used. The relay is sensitive type for high voltage.
In the figure we have a negative power circuit for SCR and unijunction transistor suggested by...
We found this oscillator in a documentation for radio amateurs from the 1970s. The circuit can use...
This 5 V power supply for TTL, Shields and microcontrollers is old, and the components can be...