Abstract: An apparatus (1) for detecting gas (4) in a high-voltage device (3) filled with an insulating medium (2) comprises an inlet (5) for introducing a carrier gas (16) and an outlet (6) for discharging a carrier gas (16); at least one gas sensor (12) for detecting a gas (4); a first pump (9) for conveying the carrier gas (16) in the apparatus (1); a membrane (13) which at least consists of at least one semipermeable material, is at least partially surrounded by the insulating medium (2) and is at least partially subjected to a flow of the carrier gas (16); a second pump (10) for conveying the carrier gas (16) into the apparatus (1) and for conveying the carrier gas (16) out of the apparatus (1); wherein there is no valve which can be used to convey the carrier gas (16) into the apparatus (1) or out of the apparatus (1).

Abstract: The invention relates to a device for representing and displaying the coil temperature of an electrical power transformer and to an electrical circuit suitable therefor. The invention is based on the general concept of using the CT-signal current not only for supplying the heating resistor of a sensor, for example, but also for decoupling energy from the CT-signal current by transformation via an electronic circuit according to the invention in order to supply energy to the connected measurement devices, so that a separate energy source can thus be ultimately omitted.