SU1663589A1 - Magnetic disk magnetic parameter measuring device - Google Patents

Abstract

The invention relates to a measurement technique and can be used to determine the quality of coatings of magnetic disks during their manufacture. The purpose of the invention is to increase the reliability of control by expanding the list of monitored parameters. The electromagnet 11 magnetizes the magnetic disk 22 to saturation, then the magnetic head 18 reversal the selected control area in the opposite direction. According to the signals of the command generator 3, a stepwise reverse magnetization is performed, in which the output signal is read by the magnetic head 18. The results of the initial magnetization reversal are stored in the memory block 7 and compared with the current value of the magnetization. When the equality is reached, the magnitude of the magnetizing current is fixed and the magnitude of the corresponding magnetic field is indicated by the reading unit 15. 1 Il.

Description

The invention relates to a measuring technique and can be used in determining the quality of coatings of magnetic disks during their production.

The purpose of the invention is to increase the reliability of control by expanding the list of monitored parameters.

The drawing shows a block diagram of the device.

The device contains an adapter 1 connected in series, an address index generation unit 2, a command driver 3, a playback amplifier 4, an integrator 5, an analog-digital converter 6, a memory block 7, the second input of which is connected to the command driver 3, a comparison unit 8, the output of which connected to adapter 1, trigger 9, the output of which is connected to the driver of 3 commands, block 10

current control, the second and third inputs of which are connected respectively to the driver 3 commands and block 2 forming address indices, and the electromagnet 11.

In addition, the device contains serially connected digital-to-analog converter 12, the input of which is combined with the second input of comparator unit 8 and connected to analog-to-digital converter 6, and the output connected to adapter 1, and a contact socket 13 connected in series with sensor 14 field placed in the gap an electromagnet 11 and connected to the adapter 1, the reading unit 15 and the contact socket 16 connected to the sensor 14, the floor. The device also contains a serially connected recording amplifier 17 connected to the outputs.

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a driver 3 and an address index indexing unit 2, and a magnetic head 18, the input of which is combined with the second input of the playback amplifier 4, and a series-connected rotation block 19, the first input of which is connected to the adapter 1, the second input combined with the input of the command 3 generator of the trigger 9 and memory block 7 and connected to the adapter

1 and a positioning unit 20, the second input of which is combined with the input of the current control unit 10 and connected to the output of the unit

2 forming address indices, the output of the positioning unit 20 is electrically connected with the inputs of the driver 3 commands and the current control unit 10 and mechanically with the magnetic head 18 and the electromagnet 11.

The device also includes a button 21 connected to the adapter.

In addition, the drawing shows a controlled magnetic disk 22 mechanically coupled to a spin box 19.

The device works as follows.

The process of controlling the magnetic disk 22 is carried out by registering its residual magnetization and consists of the following steps: magnetizing the magnetic disk 22 with an electromagnet 11 until saturation, magnetizing the controlled area of the magnetic disk 22 with a magnetic head 18 to the maximum reciprocal, remembering half the value of the reproduced signal, sequential demagnetization of the magnetic disk 22, comparison of the current values of the magnetization with the stored one and recording of the magnitude of the demagnetizing field and cient magnetization equal to half the maximum value.

After switching on the device from adapter 1, the code of the address of the track radius and the position on the track of the magnetic disk 22 enters the input of the address indices block 2. When the button 21 is pressed, the rotation block 19 rotates the magnetic disk 22. When it reaches the nominal rotation frequency, the position 20 moves the head 18 and the electromagnet 11 to a predetermined position. At the same time, the command driver 3 sets the amount of current generated by the current control unit 10, sufficient to magnetize the magnetic disk 22 to saturation. Then, the information recording mode is performed using the recording amplifier 17 and the magnetic head 18.

At the end of the recording, the device switches to the playback mode, in which the signal from the magnetic head 22 is amplified by the reproduction amplifier 4, integrated by the integrator 5, is converted into a digital code by analog-digital

converter 6 and is stored in memory block 7. “.

Then, according to the signals of the command generator 3, the current control unit 10 increases the current in the electromagnet 11, as a result of which

0, the amplitude of the reproduced signal decreases. The current amplitude value is compared with that stored in comparison unit 8 and simultaneously converted into step voltage using digital analog converter 12. When the amplitudes are equal, comparison unit 8 switches trigger 9 to zero state, the command driver 3 fixes the current value in electromagnet 11, and count 0 This unit numerically indicates the magnitude of the magnetic field of the electromagnet 11, converted into an electrical signal by the sensor 14 field.

To register a magnetic hysteresis hinge, a coordinate plotter (not shown) is connected to the pin jacks 13 and 16.

Claims (1)

The invention The device for measuring magnetic 0 parameters of magnetic disks containing a sequentially connected command driver, a recording amplifier and a magnetic head, a button, a playback amplifier, the input of which is connected to the amplifier 5 records, an electromagnet, a trigger, an address index generation unit, a rotation block, a current control block, and a reading block, characterized in that, in order to increase the reliability of the control, it 0 is equipped with serially connected by an integrator connected to the output of the playback amplifier, an analog-digital converter, a memory unit, a comparison unit whose output is connected to the trigger input and an adapter whose button is connected to the second input, and the outputs are connected to the input blocks of the address indexes and rotation, the floor sensor and the first contact socket, connected to the reading unit and the adapter, positioning unit, the first input of which is combined with the input of the command generator and the unit pack The current is connected to the output of the address index generation unit, the second input is connected to the output of the rotation unit, the output of the positioning unit is connected to the second inputs of the command generator and the current control unit, and serially connected digital-to-analog converter, the input of which is combined with the input of the comparison unit and connected to the analog-to-digital converter and the output are connected to the adapter and the second contact sockets; the second output of the trigger is combined with the second inputs of the memory block, the command driver and the block while rotating and connected to the adapter, the electromagnet is connected to the outputs via the current control unit 0 the trigger and command driver, the fourth input of the command driver is connected to the trigger output, the third output of the command driver is connected to the second input of the playback amplifier, the fourth output of the command driver is connected to the third input of the memory unit, the second input of the recording amplifier is connected to the address generation index generation unit .