A circuit arrangement is disclosed with a regulating circuit which is particularly
used for regulating a resonant converter having a plurality of outputs. The arrangement
includes a protective circuit that can be constructed with the least possible circuitry
and cost. The regulating circuit is used for generating a pulse-width modulated
regulation signal (20) in dependence on measuring signals (Va, Vb) present on inputs
of the regulating circuit (20). The arrangement further includes a comparator circuit
(212) for comparing the duty cycle () of the regulation signal (20) with
a predefinable maximum duty cycle value (max) and minimum duty cycle value
(min), in which in case of a duty cycle () situated outside the range
between the maximum duty cycle value (max) and the minimum duty cycle value
(min) the circuit arrangement delivers control information that corresponds
to this exceeding of the range.
