SU1501142A1 - Apparatus for magnetic recording with dynamic bias - Google Patents

Abstract

The invention relates to the accumulation of information and can be used for magnetic recording with dynamic biasing. The purpose of the invention is to improve the quality of magnetic recording by reducing the parasitic amplitude modulation during dynamic biasing. In each recording channel, the adder 5 performs the summation of the high-frequency components of the information signal from the high-pass filter 4, the low-frequency components of the information signal from the low-pass filter 16 and the high-frequency bias voltage from the high-frequency biasing generator 1. At the same time, the low-frequency components of the information signal increase, and the high-frequency bias voltage decreases, respectively, in the second and first amplifiers 9 and 8, if the envelope of the high-frequency components of the information signal in the comparison element 6 is greater than the limiting voltage from the limiting voltage source 7. An increase in the high-frequency components of the information signal above a predetermined level leads to a decrease in the high-frequency biasing current through the recording magnetic head 10, which expands the frequency band of the recorded frequencies toward higher frequencies. At the same time, a decrease in the recording level of the low-frequency components of the information signal, caused by a decrease in the high-frequency bias current, is compensated for by the amplification of the low-frequency components of the information signal from the low-pass filter 16. 1 il.

Description

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The invention relates to the accumulation of information, in particular, to magnetic recording devices with dynamic IMC magnetization.

The aim of the invention is to improve the quality of magnetic recording by reducing the parasitic amplitude modulation during dynamic magnetization.

The drawing schematically shows one of the variants of the proposed device for magnetic recording with dynamic biasing.

The device contains a high-frequency bias generator 1 and two recording channels, each of which is equipped with a recording amplifier 3, a high-pass filter 4, an adder 5, a comparison element 6, a reference voltage source 7, a first and second controlled amplifiers 8 and 9, and recording magnetic head 10, voltage-current converter 11 and input bus 12, In each recording channel 2, recording amplifier 3 is connected by input to input bus 12 and is connected by output to input of high-pass filter 4 connected by output to first input of adder 5, and the reference element 6 is connected by a first input to the output of the reference voltage source 7. At the same time, the output of the high frequency bias oscillator 1 is connected to the information inputs of the first controlled amplifiers 8 in channels 2 of the recording.

Each recording channel 2 is equipped with first and second attenuators 13 and 14, connected outputs to the control inputs of the first and second controlled amplifiers 8 and 9, respectively, the first and second lower filters 15 and 16, quad 17 and inverter 18 form of an inverting amplifier. In each recording channel 2, the output of the high-pass filter 4 is connected through the quad 17 connected in series and the first low-pass filter 15 to the second input of the comparison element 6, the output of which is connected to the input of the second attenuator 14 and connected via an inverter 18 to the input of the first attenuator 13. in each recording channel 2, the output of recording amplifier 3 is connected via the second low-pass filter 16 to the information input of the second controlled amplifier142

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l 9 connected by an output to a second input of the adder 5, which is connected by a third input to the output of the first controlled amplifier B and connected by an output via a voltage-to-current converter 11 to a recording magnetic head 10.

The device for magnetic recording with dynamic bias works as follows.

In each channel 2 of the recording information signal to be recorded through the amplifier 3 recording, providing its frequency correction, passes to the second low-pass filter 16 and high-pass filter 4. The high-pass filter 4, whose cut-off frequency lies in the frequency range of 500-1000 Hz, extracts from the spectrum of the information signal the high-frequency components supplied to the quadrant 17. The result of quadratic detection from the quad 17 goes to the first low-pass filter 15, which ensures the envelope of the high frequency components of the information signal, which is compared in the reference element 6 with the reference voltage from the source 7 of the reference voltage. At the same time, the reference voltage corresponds to the maximum value of the high-frequency components of the information signal, at which there is no need to reduce the high-frequency bias current in the recording magnetic head 10. If the envelope value of the high-frequency components of the information signal exceeds the reference voltage, the comparison element 6 forms control differences of the difference signal which is fed to the control input of the second controlled amplifier 9 directly, and to the control input of the first amplifier It is transmitted through the inverter 18. The latter causes the gain of the second controlled amplifier 9 to increase, and the gain of the first controlled amplifier 8 to decrease in proportion to the value of the control of the difference signal from the reference element 6.

In each channel 2, recording the high-frequency components of the information signal from the high-pass filter 4 is fed to the first input of the adder 5, the low-frequency components from the second low pass filter 16 pass through the second controlled amplifier 9 to the second input of the adder 5, and the high-frequency voltage - magnetization from the high-frequency biasing generator 1 through the first controlled amplifier 8 passes to the third input of the adder 5. The result of the summation from the output of the adder 5 operates through the voltage converter 11 e-current on the recording magnetic head 10, which provides magnetization of the magnetic recording medium.

In each recording channel 2, an increase in the energy of the high-frequency component of the information signal above a predetermined level determined by the source 7 of the reference voltage leads to a corresponding decrease in the high-frequency biasing current through the recording magnetic head 10, which ensures that the frequency band of the recorded frequencies is expanded towards higher frequencies. Simultaneously, a decrease in the recording level of the low-frequency components of the information signal, caused by a decrease in the high-frequency bias current in the recording magnetic head 10, is compensated for by an increase in the gain in the second controlled amplifier 9 of the low-frequency components of the information signal from the second low pass filter 16 to the adder 5 .

Claims (1)

Invention Formula A device for magnetic recording with dynamic biasing, containing a high-frequency generator 40 formational input of the second controlled amplifier connected by the output to the second input of the adder, which is connected to the output of the third input the first controlled amplifier and coupling and recording channels, each output through the converter, of which is equipped with a voltage-current amplifier with a recording magnetic recording, a high-pass filter, a sum head. - - t 501142 a reference element, a voltage source, a first and second controllable amplifiers, a magnetic recording head, a voltage-current converter and an input bus; in each recording channel, the recording amplifier is connected to the input bus and connected to the input bus frequency, connected by the output to the first input of the adder, and the comparison element is connected by the first input to the output of the reference voltage source, which is 15 in order to increase the quality of the magnetic recording by decreasing Parasitic amplitude modulation with dynamic bias, the output of the high-frequency biasing generator 20 is connected to the information inputs of the first controlled amplifiers in the recording channels, each of which is equipped with first and second attenuators, 25 connected outputs to the control inputs of the first and second controlled amplifiers, the first and second low-pass filters, the quad and the inverter, respectively; 30 each recording canape, the output of the high-pass filter is connected through the quadrant and the first low-pass filter connected in series to the second input of the reference element, the output of the core of which is connected to the input of the second attenuator and connected via an inverter to the input of the first attenuator, and the output of the recording amplifier is connected via the second filter low pass with informational input of the second controlled amplifier connected to the output of the second input of the adder, which is connected to the output of the third input Editor Y. Sereda Compiled by Yu.-K.V. Rozenkrantz Tehred M. Khodanych Order 4877/49 Circulation 558 VNIIPI State Committee for Inventions and Discoveries at the State Committee for Science and Technology of the USSR 1131 35, Moscow, Zh-35, 4/5 Raushsk nab. Proofreader M. Pojo Subscription