Abstract: A moisture detection system (100) comprises a cable (102), a voltage regulator (104) and a differential amplifier (106). The cable (102) comprises an elongated non-conductive moisture permeable structure (108), a first elongated lead (110) and a second elongated lead (112). The first and second leads (110, 112) are substantially equal in length and are connected to the differential amplifier (106) and arranged such that they are not in galvanic contact with each other at any location along the cable (102). The voltage regulator (104) is configured to supply a regulated voltage to the first lead (110) and to the differential amplifier (106). The differential amplifier (106) is configured to determine a voltage difference between the first and second leads (110, 112), and configured to provide a signal that is representative of the determined voltage difference.

Abstract: A device for displaying a parameter value has at least one row of light-emitting diodes in which each light-emitting diode has a position input, and the device has a control circuit with address outputs connected to the position inputs. Faults, such as a short-circuit can be detected more easily by an improved interconnection of the address outputs and position inputs such that two adjacent address outputs are connected to two position inputs physically separated by at least one position input.

Abstract: An apparatus, such as a ventilator, for regulating the flow-through amount of a flowing medium, such as a gas, has a valve with a variable orifice operated by a first regulating circuit with negative feedback. The regulating variable generated by the first regulating circuit controls the size of the orifice so that the difference between a desired value and an actual value for the flow-through amount os minimized, toward zero. To achieve rapid changes in the flow-through amount with a high regulating precision, at least one further regulating circuit is provided to which the regulating variable of the first regulating circuit is supplied as the desired value. The actual value for the further regulating circuit may be the measured position of the closure element for the orifice. The bandwidth and the gain can be optimized for each regulating circuit. The energy consumption can be lowered by current recovery and battery operation can be simplified, in the event of a power outage.