[sdiy] soft PSU turn on circuit needed

[Martin Czech]

Torroid transformers are nice, but they draw excessive current on
turn on. Therefore a softer starter circuit is needed.  So far I use a
little parallel 230/12 transformer that feeds a RC time delay and that
in turn feeds a relay. This relay will short the 200 Ohm soft turn on
resistor. This works for my bench supply for years , now.

Obvious problem: not fools save. if you toggle the mains switch fast
enough, the relay will not follow, the resistor keeps shorted and the
fuse will blow again.

Is there any simple circuit on the web, long turn on timke, quick
fall off?

m.c.