| 摘要 |
The invention creates an electronic resistor suitable, in particular, for measuring technology, which can replace conventional discrete measuring resistors. To simulate such a resistor, a closed-loop control circuit is used which includes a controlling element, the resistance value of which is determined by a manipulated variable. The manipulated variable is formed from the difference between a controlled variable and a reference variable. As a controlled variable, either the ratio of the voltage (U) dropped across the electronic resistor to the current (I) flowing through the controlling element (1) or, alternatively, the current (I) flowing through the controlling element or the voltage (U) dropped across the electronic resistor is used. The closed-loop control circuit is built up with the aid of a differential amplifier (3), which generates the manipulated variable, a current/voltage converter (2) located in series with the controlling element (1), a controlling element (1), a divider (4) or multiplier (5), a digital/analog converter (6) and a digital drive circuit (7). <IMAGE>
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