Monitor for current circuit of appliance, e.g. separate lamps of motor vehicle - uses differential amplifier as comparator with inputs across fuse and output supplying warning appts. if heat exceeds threshold value

摘要

A load circuit monitoring arrangement contains a measurement resistance in the leads to at least one load (1). The resistance input is connected to one comparator (4) input via a potential divider (3) and its output is connected to the other comparator input. The comparator drives a warning device. The fuse (2) in the lead to the load can be used as the measurement resistance. For functional monitoring of the load the threshold of the comparator is matched to the load current and the variation in the resistance of the fuse with temp. ADVANTAGE - Contains min. number of components and occupies relatively little space. Measurement resistance does not introduce any additional potential drop in load circuit or generate additional heat loss.