negative voltage

Hey! I came across this circuit (see attached picture) which is used to create a -15V from a 15V rail then used as an input for a negative voltage regulator. I couldn't understand quite how the circuit works! Can someone explain this for me please? PS: the 2 diodes are in the same die, and i...

I have a media cabinet which houses a bunch of media players/routers/alarm system etc. The target output voltages for each component is between 9V and 24V. This is currently powered by an LED power supply with a few step down buck converters to the target voltages. The LED power supply is very...