Phil Allison wrote:
Cursitor Doom wrote:



So far as SMPSs are concerned, though, I don't believe they can be
actually *damaged* by under-voltage; not start/function properly, yes,
but damage? I'm very doubtful about that.


** There are certainly many SMPSs with start up modes that create brutal current surges for the switching mosfet or mosfets. The electros on the secondary side of the switching tranny present a near short until charged and there has to be some effective means built into the circuitry to limit peak currents until this happens.

Using a variac, it is sometimes possible to find a setting where the PSU attempts to start, surges repeatedly, but cannot successfully run - likely because the secondary voltage does not rise enough for the control loop to stabilise.

Reckon it is wise to avoid lingering at such a setting.

Television sets (with CRT) really don't like brownouts either.