Digital constant-temperature control circuit applied to moving base gravimeter

Abstract

The invention relates to a digital constant-temperature control circuit applied to a moving base gravimeter. The digital constant-temperature control circuit is composed of a temperature measurement circuit, a digital signal processing circuit, a driving circuit and a power supply circuit. The temperature measurement circuit consists of a precision reference voltage source, a temperature measuring bridge, a multi-channel change-over switch, an instrument amplifier, and a low-pass filter. The digital signal processing circuit includes an A / D sampling chip, a DSP chip, and an FPGA chip. The driving circuit includes an optocoupler, a protection diode, an MOS tube, a heating resistor and a fan. The power supply circuit consists of a + / - 15-V module, a 5-V module, a 12-V module and a 3.3-V module. A temperature measurement bridge is formed by using a high-precision resistor and a platinum resistor and selection of the resistance of the high-precision resistor uses the resistance of the platinum resistor under the target temperature value as a reference, so that measurement noises of the temperature measurement bridge are minimized when the controlled temperature is close to the target temperature value and thus high-resolution temperature measurement is realized.

Description

technical field [0001] The invention relates to a digital constant temperature control circuit control applied to a gravimeter of a movable base, belonging to the technical field of temperature measurement. Background technique [0002] The moving base gravimeter is a precision measuring device for measuring the earth's gravitational field on a mobile carrier. The accuracy of its core components—the accelerometer and the I / F circuit is significantly affected by temperature. The high-precision moving base gravimeter must Equipped with high-precision constant temperature control circuit. The traditional constant temperature control circuit can be divided into three types: full analog, semi-analog and half-digital, and all-digital according to whether the temperature measurement link includes A / D sampling and whether the temperature control link adopts pulse width modulation. It will introduce A / D sampling noise, but it is convenient for the realization of digital control and ...

AI Technical Summary

Problems solved by technology

The traditional constant temperature control circuit can be divided into three types: full analog, semi-analog, semi-digital and full digital according to whether the temperature measurement link includes A / D sampling and whether the temperature control link adopts pulse width modulation. It will introduce A / D sampling noise, but it is convenient for the realization of digital control and complex algorithms. The analog temperature measurement circuit will not introduce sampling noise, but it is difficult to realize the control algorithm and adjust the control parameters. The digital temperature control circuit needs to introduce complex digital signals. Processing circuit, but the execution accuracy of temperature control is better than that of analog temperature control circuit; traditional constant temperature control circuit also has excessive measurement noise and amplification noise, low temperature measurement resolution, and limited number of temperature measurement and temperature control circuits And other issues

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