System for setting an analog resistor to a selectable, digitally predeterminable value

摘要

An arrangement for setting an analog resistor to a value which is digitally predetermined. The arrangement contains a resistor (2) which is variable by a control voltage as setting member of a control circuit, in series with a measurement resistor (3) and a rotary-magnet ratio meter (26). This series connection is fed from an operating voltage. The voltage at the measurement resistor (3) and the digital value are each fed to inputs of a multiplier (5) the outputs of which are connected via a digital/analog converter (6) to an input of a subtraction circuit (7). The other input of the subtraction circuit (7) is acted on by a reference voltage. The output of the subtraction circuit (7) produces the control voltage for the adjustable resistor (2).