Abstract: An electric drive unit includes an electric motor for driving a fan. The motor has an electronic control module. An impeller wheel for producing a working air flow is mounted by bearings on an axle of the electric motor. The hub of the impeller wheel has at least one preferably two walls enclosing a cooling space or cooling space portions. At least one cooling surface of a cooling body is in contact with components of the electronic control module and projects into the cooling space. A gap formed between the hub of the impeller wheel and a carrier section communicates with an inner hub space. Holes (43, 322) communicating with the hub inner space are provided in at least one component of the electric drive unit. When the impeller wheel rotes a convection cooling air flow is established between the gap and the holes.

Abstract: The invention relates to an electric drive unit comprising an electronic control module and an electric motor. The cooling of the components of the electric drive unit should be effected in a simple manner. To this end, the hub of the impeller wheel, which is situated on the rotation axis of the electric motor and provided for producing a working air flow, has a two-walled design, whereby a hub inner space is formed between the outer wall and the inner wall of the hub of the impeller wheel. At least one cooling surface of the cooling body, said surface being in contact with components of the electronic control module, projects into the hub inner space. A gap communicating with the hub inner space, is formed between the hub of the impeller wheel and a carrier section which supports the electronic control module and the electric motor. In addition, through-holes communicating with the hub inner space are provided in at least one component of the electric drive unit.

Abstract: A process for monitoring an opening of an enclosed space by an IR alarm system, wherein: a measuring process is generated whereby a modulated IR beam is emitted by at least one IR emitting element of an optoelectronic unit in the form of a pulse and the beam reflected from marginal areas of the opening is detected as a measurement signal by at least one IR receiving element of the optoelectronic unit, with the directional characteristic of th IR beam being matched, by optical components in the path of the beam, to the opening being monitored; the measurement signal detected by the receiving element is compared with a mean value of the previous measurement signals, and a normal operating mode of the alarm system is initiated if there is an approximate correlation between the measurement signal and the mean value, or an alarm operating mode of the alarm system is initiated if there is a significant deviation between the measurement signal and the mean value; in the normal operating mode, the next measuring proc