To ensure the proper operation of the Nuclear Magnetic Resonance Gyroscope (NMRG), a dedicated amplitude control circuit has been designed for the gas chamber. This circuit aims to fulfill the high-temperature heating requirements of the gas chamber, including achieving saturated vapor pressure, higher density, and ensuring the precise temperature stability of the gas chamber. The stability is of utmost importance as it directly impacts the accuracy of the NMRG. The circuit employs a voltage-output DAC1220, connected in series with a resistor, to drive the FS ADJUST pin of the AD9834. This configuration allows precise adjustment of the amplitude of the full-scale DAC current. The resulting signal is then amplified using a current-to-voltage conversion resistor and an Enhanced Howland Current Source (EHCS) circuit, effectively meeting the requirements for heating the gas chamber. The simulation and experiment show that the successful achievement of an AC sinusoidal heating signal with a frequency of 100KHz and a precise amplitude adjustment rangeof0-150mA.The adjustable step size of 0.01v ensures fine-tuned control. These findings validate that the heating signal fulfills the requirements for high-frequency electrical heating of the gas chamber in the NMRG.
We design a laser driver and temperature control circuit based on the Field Programmable Gate Array (FPGA). Vertical-Cavity Surface-Emitting Laser (VCSEL) is the core device of the nuclear magnetic resonance gyroscope (NMRG). The accuracy of the laser output wavelength greatly affect the detection accuracy of NMRG. In order to improve the accuracy of VCSEL in this application system, in this paper we research the working principle of the laser and analyze the relationship between the laser output wavelength, the driving current and the laser operating temperature through theoretical analysis. We design and built the laser driving and temperature control circuit by using constant current source and the MAX1978, which use FPGA as the main control chip. By setting different voltage values, the laser output corresponds to different wavelengths. We analyze the result of experiment and theoretical calculate through the spectrometer. The result shows that the current regulation error is better than 0.03mA. For the laser temperature control circuit, we used the LTSPICE to simulate the PID control circuit of the compensation loop ,the finally result is consistent with the expected results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.