Load actuation device e.g. for motor vehicles, uses load current limiting device for limiting the load current through the output transistor to a given value depending on current through detection transistor

摘要

Load-actuating circuits function to provide a load current below a given level of current with a high level of precision and free from the effects of temperature changes and any shortcomings in the operating characteristics of the various circuit elements, and a detection transistor is used with its control terminal electrically joined to the control terminal of the output transistor, so as to generate a current flow proportional to the load current. A load current limiting device limits the load current through the output transistor to a given value on the basis of the current flow through the detection transistor. A constant current source supplies a constant current, as a control signal for actuating the load, to the control terminal of the detection transistor.