On Sun, Mar 1, 2020 at 11:04 PM, Gary Robert Bosworth wrote:
The reason why I do not like this design is because of the fact that the -30V output is used to bias the 6.2V reference diode VR772. This poses a classic lock-up condition in that if the -30V does not exist, then the reference diode is never turned on.
I think that's incorrect: Whenever - 40 V is present, Q788 is pulled into conduction by R787 (to gnd), causing the output voltage to move from 0 V towards - 30 V. The regulating circuit *reduces* that conduction by increasing conduction of Q786.
