Electric heating for heating the air which is fed into a vehicle interior, has control unit that changes transistor control voltage within variable period if power loss reaches limit to reduce working point to below power loss limit

摘要

The arrangement has at least a first transistor (30) in series with at least a first heating element (16). The transistor resistance is adjusted to influence the current in the series circuit. A device is provided for determining and/or estimating the power loss of the first transistor(s) and a control unit (40) that changes the transistor control voltage in a variable period if the power loss reaches a limit to reduce the working point to below the limit.