Switching converter to convert an input direct current (U.sub.E) into at
least one output direct current (U.sub.A), wherein an internal auxiliary
voltage (U.sub.H1, U.sub.H2) is derived from at least one auxiliary
winding (W.sub.H1, W.sub.H2) of a transformer (Tr), a controllable load
element (BAL) is provided for the output voltage, and a stop signal
(s.sub.s) can be fed to turn the output voltage of the switching
converter ON/OFF, which is used to connect the load element (BAL) to the
output direct current to such an extent that a short-circuit-like
condition is produced, in which the output voltage (U.sub.a) is
adequately close to null, but the at least one auxiliary voltage
(U.sub.H1, U.sub.H2) is adequately high to supply the units associated
therewith.