Multi-channel high-precision current source and working method thereof

Abstract

The invention discloses a multi-channel high-precision current source comprising a controller, a multi-channel DAC, a plurality of V / I conversion circuits, a plurality of load detection circuits, a multi-channel ADC and a temperature sensor; the controller is electrically connected with the multi-channel DAC; two outputs of the multi-channel DAC are electrically connected with each V / I conversion circuit, and the i V / I conversion circuit is electrically connected with the i load detection circuit; the number n of the load detection circuits is equal to the number of the V / I conversion circuits, each load detection circuit is electrically connected with one path of input of the multi-channel ADC, the multi-channel ADC is electrically connected with the controller, the temperature sensor is electrically connected with the controller, each path of V / I conversion circuit and the corresponding path of load detection circuit form a path of current source; and the input of the current source is two paths of output of the multi-channel DAC, and the detection output of the current source is connected to one path of input of the multi-channel ADC. The current source can solve the technical problem that an existing shimming current source cannot meet the high-resolution requirement of a nuclear magnetic resonance spectrometer for current control.

Description

technical field [0001] The invention belongs to the technical field of nuclear magnetic resonance, and more specifically relates to a multi-channel high-precision current source for a nuclear magnetic resonance spectrometer and a working method thereof. Background technique [0002] The nuclear magnetic resonance spectrometer requires that the non-uniformity of the magnetic field of the superconducting magnet in the measurement area is less than 10% of the main magnetic field -9 , in order to meet this requirement, 20-40 groups of mutually orthogonal coils are often used, and a shim current source is used to apply appropriate current to these coils, so that each group of coils generates mutually orthogonal magnetic fields whose size can be controlled by current , to cancel the inhomogeneous magnetic field in all directions. [0003] Objectively speaking, the shimming current source needs to meet the following requirements: [0004] 1) It can provide as many current circuit...

AI Technical Summary

Problems solved by technology

[0015] In view of the above defects or improvement needs of the prior art, the present invention provides a multi-channel high-precision current source and its working method for nuclear magnetic resonance spectrometers, the purpose of which is to solve the unsatisfactory existing shimming current source The technical problems of nuclear magnetic resonance spectrometer's high-resolution requirements for high-precision current control, as well as the technical problems of occupying a large space, and because of the different output biases of each component, the actual output current of each current source and the setting There are technical problems of different deviations between currents, and the technical problem that the current output by each current source will gradually drift due to the temperature drift characteristics of each component after working for a period of time

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