Active variable resistor

Abstract

The invention discloses an active variable resistor which inputs a set resistance value through an upper computer, the upper computer transmits the resistance value to a single-chip microcomputer MCUfor processing, and the single-chip microcomputer MCU determines the on-off positions and number of MOS transistors according to the set resistance value and port voltage and controls VCVS voltage tosimulate a small-resistance resistor. The MCU detects the change of current and voltage to obtain the change of the resistance value of the whole circuit, and controls the MOS transistors or VCVS voltage through a built-in incremental PI algorithm of the MCU, thereby achieving the temperature compensation of the resistor, and reducing other additional errors. According to the invention, the resistance value can be read and adjusted conveniently, a mechanical structure is avoided, the size is reduced, certain stability is achieved, and the circuit has a wide prospect in the field of circuit design.

Description

technical field [0001] The invention relates to the field of circuit design, in particular to an active variable resistor. Background technique [0002] The traditional resistance box adjusts the resistance knobs of different multiples by rotating the knob to achieve the purpose of switching different resistance values. This type of rheostat box is often used as a teaching aid display. It is more flexible to change the resistance value, but it is large in size and needs to be manually changed. , It is not conducive to integration, the resistance switch needs manual operation, and there are mechanical contacts, it is easy to appear a large contact resistance after a period of use. The traditional resistance box will gradually heat up after working for a period of time, causing the resistance value to change, but for this type of resistor with a slightly larger range, using the traditional self-compensation method and bridge compensation method will increase the complexity and...

AI Technical Summary

Problems solved by technology

[0002] The traditional resistance box adjusts the resistance knobs of different multiples by rotating the knob to achieve the purpose of switching different resistance values. This type of rheostat box is often used as a teaching aid display. It is more flexible to change the resistance value, but it is large in size and needs to be manually changed. , It is not conducive to integration, the resistance switch needs manual operation, and there are mechanical contacts, it is easy to appear a large contact resistance after a period of use

The traditional resistance box will gradually heat up after working for a period of time, causing the resistance value to change, but for this type of resistor with a slightly larger range, using the traditional self-compensation method and bridge compensation method will increase the complexity and increase the cost.

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