| 摘要 |
A circuit arrangement is proposed which has the object of both switching loads on and off and also monitoring them, by means of a high-power field-effect transistor (28). The voltage drop on the field-effect transistor (28), which voltage drop is dependent on the load current, is for this purpose supplied to a threshold switch (33) whose switching state is sensed at two predetermined times during the switching-on process of the load, and whose switching threshold is set such that it is exceeded by the switching-on current at the first sensing time when the load is intact, and such that it exceeds the normal operating current at the second sensing time. In this case, the monitoring circuit (13) emits a signal as a function of the sensed switching states of the threshold switch, which signal indicates an interruption, an overload or a short-circuit, as well as an intact load circuit. The circuit arrangement can be used for monitoring loads having an increased switching-on current, preferably for incandescent lamps, motors and magnet coils (Figure 2). <IMAGE>
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