The circuit shown was found in Intersil documentation from the 90s. The formula allows to calculate the voltage obtained as a function of the values of the resistors.
This is a circuit with the first commercial Darlington transistor, the 2N626. The circuit is from...
This circuit was found in a Maxim documentation from the 90s. It is valid for the lower income types...
We found this circuit in a 1971 documentation. The circuit can be assembled with more modern...