Abstract: A solar module has a solar cell which generates a DC voltage. The module has a converter for converting a DC voltage fed into its input. The module contains a semiconductor switch and a controller which drives a switching input of the semiconductor switch. The controller drives the semiconductor switch variably so that the semiconductor switch switches more slowly during the transition operation than during normal operation, thereby reducing a dynamic overvoltage on the switch such that the voltage present on the switch does not exceed the blocking voltage of the switch.

Abstract: A solar module has a solar cell which generates a DC voltage. The module has a converter for converting a DC voltage fed into its input. The module contains a semiconductor switch and a controller which drives a switching input of the semiconductor switch. The controller drives the semiconductor switch variably so that the semiconductor switch switches more slowly during the transition operation than during normal operation, thereby reducing a dynamic overvoltage on the switch such that the voltage present on the switch does not exceed the blocking voltage of the switch.

Abstract: To determine the density of a stream of fibrous material on a cigarette manufacturing machine, two different measurements are performed, the first of which is capacitive and supplies a first signal as a function of the density of the dry component and of the density of the liquid in the stream of fibrous material, and the second of which is optical and supplies a second signal indicating the density of the dry component; the second signal is combined with the first signal to obtain a third signal indicating the density of the liquid in the stream of fibrous material; and, from the third and second signals, a fourth signal is obtained indicating the density of the stream of fibrous material as the sum of the density of the dry component and of the liquid in the stream of fibrous material.

Abstract: For scaring birds, at least two acoustic signals are generated whose frequencies are periodically modulated within a range between about 30 and 9000 Hz, the modulation period ranging between about 0.01 and about 5 seconds. The signals differ in the frequency modulation range, in the modulation period and/or in duration. The signals are emitted either in fixed or in arbitrary sequence.