Current-limiting resistor having PTC behavior

摘要

The current-limiting resistor has two connection electrodes (1, 2) which are arranged parallel to one another as well as a resistance body (3) which has PTC behavior and with which large-area contact is made by the connection electrodes (1, 2). A varistor (40) is in electrically conductive contact with the resistance body (3). The resistance body (3) contains two contact areas (50, 51) as well as a response point (60) which is connected in parallel with the varistor (40) via the two contact areas (50, 51) and implements a PTC transition above a threshold value of a current flowing through the resistor. Since the resistance body effects the electrical contact with the varistor (40) in the case of this resistor, no metal connection electrodes are required for the varistor. At the same time, due to the outward displacement of the response point (60) away from the varistor (40), the operational reliability of the resistor is considerably improved. Effective current limiting in load circuits which are operated at high voltage can be achieved by a series circuit formed by a plurality of varistors (40, 41, . . . ) provided in a resistance body (3) which is designed in the form of a meander or is of some other continuous design.