Constant temperature hot wire anemometer Wheatstone bridge matching resistance temperature stability control system

Abstract

The invention relates to a temperature stabilization control system for a Wheatstone bridge matching resistance of a constant temperature hot wire anemometer, comprising a constant temperature island and a constant temperature island controller, wherein three matching resistors of the Wheatstone bridge are arranged on the constant temperature island, and the constant temperature island is controlled by heat dissipation The device, the semiconductor cooling plate, and the cooling platform are stacked from bottom to top. When working, as the wind speed increases, the Wheatstone bridge current controlled by the amplifier of the anemometer will increase, resulting in the generation of three matching resistors. As the heat increases, the temperature of the three matching resistors rises. The constant temperature island controller adopts PWM modulation to control the working current of the cooling chip, controls the cooling capacity of the cooling chip, and takes away the heat dissipated by the three matching resistors through the cooling platform and heat dissipation system. , to keep the temperature of the three matching resistors constant. Advantages: It overcomes the deviation of the superheat ratio set value of the anemometer and the problem of inaccurate measurement results, avoids the problem of hot wire being blown due to excessive temperature, improves work reliability, and reduces maintenance costs.

Description

technical field [0001] The invention relates to a temperature stabilization control system for a Wheatstone bridge matching resistance of a constant temperature hot wire anemometer, which belongs to the field of testing and control. Background technique [0002] The constant temperature hot wire anemometer is widely used in the velocity measurement of the fluid. It uses the heat exchange between the fluid and the hot wire and the control circuit to heat the hot wire to reach a thermal equilibrium state, so as to maintain the hot wire at a constant temperature, and then the hot wire works. The magnitude of the current indirectly senses the velocity of the measured fluid. In the control circuit of the constant temperature hot wire anemometer, the heating wire resistance and the other three matching resistors with fixed resistance constitute a Wheatstone bridge. Superheat ratio, which corresponds to the operating temperature of the hot wire. The superheat ratio of the constan...

AI Technical Summary

Problems solved by technology

[0006] The obvious advantage of the present invention is: through the stable temperature control of the matching resistance of the Wheatstone bridge of the constant temperature hot-wire anemometer, it fundamentally overcomes the temperature change of the matching resistance caused by the change of the working current of the Wheatstone bridge of the anemometer, and then The resistance value of the matching resistor changes, which eventually leads to the deviation of the set value of the superheat ratio of the anemometer, and the problem of inaccurate measurement results

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