SU836607A1 - Device for stabilizing and measuring residual magnetization of permanent magnets - Google Patents

Description

(54) DEVICE FOR STABILIZATION AND MEASUREMENT OF RESIDUAL MAGNETICITY OF PERMANENT MAGNETS

the value of the test constant magnesium.

However, it is impossible to calibrate and measure the residual magnetization of the permanent magnets.

 The aim of the invention is to improve the accuracy and speed of calibration of permanent magnets.

This is achieved by the fact that an automatic calibration unit is added to a device containing an incompletely closed magnetic system, a master oscillator, whose input is connected with a mode switch, an output to a magnetization converter and serially connected digital balancing system and a digital readout device. the form of serially connected first key, element of comparison, amplifier, amplitude detector, phase-sensitive detector, controlled source and the alternating current of the second key and the converter of the code into the voltage connected to the second input of the comparison element, as well as the low frequency generator connected to the control inputs of the phase sensitive detector and the controlled AC source and the first input of the first key connected with the output of the magnetization converter, and the first input of the second key - with the output of the digital balancing system, their second inputs - with the mode switch, and the output of the controlled variable-voltage source with magnetic system.

The drawing shows a block diagram of an automatic device for calibrating and measuring the residual magnetization of permanent magnets.

The proposed device includes a mode switch 1, a master oscillator 2, a digital equalization system 3, a digital readout device 4, a magnetization transducer 5, a first switch 6, a comparison element 7, an amplifier 8, an amplitude detector 9, a phase-sensitive detector 10, a variable source source current 11 incompletely closed magnetic system 12, low frequency generator 13, converter 14 code to voltage, second switch 15.

The device works as follows.

Permanent magnets are calibrated or stabilized in two cycles.

At the beginning of the first cycle, the residual magnetization of the control sample is measured and its value is memorized by a code-to-voltage converter. For

this is triggered by a signal via mode switch 1 A master oscillator 2 is opened which supplies the digital equilibration system 3, and a magnetization converter 5,

The measuring signal corresponding to the value of the residual magnetization of the control sample is fed to the input of the digital balancing system, measured by it and recorded using a digital reading device. 4. At the same time, the measuring signal is memorized by the converter 14 code to voltage.

In the second cycle, the mode of calibration or stabilization of permanent magnets is performed. To do this, the test sample is placed in the gap of the magnetic system, magnetized it, then automatically demagnetized to a predetermined level of residual magnetization.

The last mode is as follows. The key 6 opens the signal from the mode switch and the key 15 closes. From this point, the value of the residual magnetization reference signal measured by the digital balance system and stored by the code-to-voltage converter 14 in the first cycle is compared to the true value of the residual magnetization of the test sample using the element Comparison 7. Amplified by the amplifier 8 of the alternating current the difference of these signals from the comparison circuit is fed to the input of the amplitude detector 9, which filters out high the ac component of the ac current due to the master oscillator. From the output of the amplitude detector, the measurement signal is fed to the input of the phase-sensitive detector 10. The output signal from the phase-sensitive detector is controlled by a low-frequency alternating current source 11, the frequency of which sets the low-frequency generator 13. The alternating current and demagnetizing magnetic field in the magnetic system gap will occur until as long as the signal from the magnetization converter corresponding to the measured value of the residual magnetization is not reached the value of the reference signal.

The proposed device has a higher performance and has high accuracy in comparison with known devices.

Claims (2)

1.Fevleva N.E. Hard magnetic 5 materials and permanent magnets. To Naukova Dumka., 1967, p. 202204. 2. USSR author's certificate number 456239, cl. G 01 R 33/12, 1973 , (prototype). 0