Buy a DC-DC converter that includes other protection
features (ie overvoltage and overcurrent protection) and
outputs known parameters (ie ripple voltage). I doubt you
will find a single DC-DC converter for both voltages. But a
small converter for each voltage should work. Many sources
including this one that just arrived on my desk -
www.astrodyne.com .

BTW, power from automotive systems should also worry about
load dump. Technically load dump can be a transient as much
as 270 volts on a 12 volt system. In reality, such events may
only be 50 volts or less. Transients that would not damage
other automotive electronics already designed for this rare
and so destructive event.

That is a problem with some regulators such as 78xx series.
Maximum voltage is typically not sufficient for automotive
purposes - would require additional protection.

"James F. Mayer" wrote:
Probably good enough for his measly 32 volts. I need to
modify that circuit to work on outputs of 90 volts and 6 volts.