SU386356A1 - AUTOMATIC DEVICE FOR MEASUREMENT - Google Patents

Description

one

Devices are known for measuring the maximum specific magnetic energy of magnetic materials based on the principle of periodic reversal of the test material, in which the signals taken from the field strength and induction sensors are multiplied, rectified by a full-wave detector and fed to a measuring device. However, such devices are not sufficiently accurate due to the fact that in order to obtain characteristics that are close to static, reversal and, therefore, signal processing and measurement must be performed at very low frequencies. In addition, the measurement result is obtained due to repeated reversal of the sample, which increases the measurement time and the energy consumed from the power source of the magnetic system.

The proposed device differs from the known ones in that it contains a digital tracking measurement device consisting of a comparison circuit, a phase-sensitive amplifier, a variable frequency generator, a non-reversible pulse counter, a code to voltage converter, and a digital reading device. Phase-phase amplifier output is connected to a Schmitt trigger, the output of which is connected to a transistor switch. Through a transistor switch, the output of the master oscillator is connected with voltage and induction sensors, a phase-sensitive amplifier, a code-to-voltage converter, and a controllable power source of the magnetic system.

The drawing is a block diagram of the described device.

The device contains a master oscillator /, transistor switch 2, sensors 3 i 4 of the field voltage and induction, respectively,

multiplying device 5, comparison circuit 6, phase-sensitive amplifier 7, Schmitt trigger 8, variable frequency generator 9, non-reversible counter 10 pulses, code-to-voltage converter, digital reading device 12, controlled source

13 power and magnetic system 14.

At the beginning of the measurement process, a trigger pulse is applied to the transistor switch 2. At the same time, a signal is applied to the pulse counter 10, which resets the previous counter reading. When the key 2 is unlocked, the voltage from the generator / enters the Hall sensors 5 and 4, the amplifier 7, the converter 11 and the source 13. The latter creates in the coils of the magnetic system

14 linearly increasing demagnetizing current.

If there is a magnetic system in the gap

magnetized sample at the sensor outputs

 and there are proportional signals.