SU1597901A1 - Device for magnetic recording of analog signals - Google Patents

Abstract

The invention relates to the accumulation of information and can be used for magnetic recording of analog signals. The purpose of the invention is to expand the frequency range of the recorded frequencies of analog signals. The device comprises a recording amplifier 1 connected to a recording magnetic head 5 through a notch filter 3 and through a high-pass filter 6 connected in series, a level detector 7, a threshold element 8 and an amplitude modulator 25 to which the erase and bias generator 9 is connected. In this case, the amplitude modulator 25 consists of an operational amplifier, in the feedback circuit of which a field effect transistor is connected. The change in the resistance of the transistor due to the effect of the signal of the threshold element 8 provides amplitude modulation of the high-frequency bias voltage coming from the erase and bias generator 9. As a result, a current is generated in the recording magnetic head, determined by the recording signal coming through the notch filter 3, and the high-frequency biasing voltage modulated by the amplitude of the threshold element 8, which is generated if the envelope of the high-frequency part of the recorded signal exceeds the threshold level. 2 Il.

Description

The invention relates to the accumulation of information, namely, devices for magnetic recording of analog signals.

The aim of the invention is to expand the frequency range of the recorded frequencies of analog signals.

FIG. 1 and 2 depict variants of the proposed device for magnetic recording of analog signals.

The device contains an amplifier

Records, the input of which is connected to the input bus 2, and the output is connected through a notch filter 3 to the first output k of the recording magnetic head 5 and connected to the input of the weighing filter 6 high frequencies connected by the output through the detector

Level 7 with the input of the threshold element 8, the generator 9 erase and rewind, erasing the magnetic head 10, the first and second capacitors

II and 12 and the first, second, third, fourth and fifth resistors 13 - 17. The erasing and biasing generator 9 is connected to the power supply buses 18 and 19 and connected via output 20 to the first output of the erasing magnetic head 10 connected to the common bus 21. At the same time common bus

21 is connected to the second output of the reproducing magnetic head 5 and to the first output of the first resistor 13.

The device also contains an operational amplifier 22 connected by output 21 through the first capacitor 11 and to the first output of the recording magnetic head 5 and connected with a non-inverting input to the second output of the first resistor 13 and to the first output of the second resistor 14 connected to the generator output 20 9 erase and drive, and the field-effect transistor 23. The field-effect transistor 23 is connected to the source to the common bus 21 and is connected to the gate via the third resistor 15 with the output 2k of the threshold element 8. The inverting input is operative on the amplifier

22 is connected with its output through the fourth resistor 16, is connected to the drain of the field-effect transistor 23 and connected via a second capacitor connected in series, the 12th fifth resistor 17 to the gate of the field-effect transistor 23. In this case, the operational amplifier 22, the field-effect transistor 23,

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five

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five

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five

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The first and second capacitors 11 and 12 and the first, second, third, fourth and fifth resistors 13-17 are included in the amplitude modulator 25.

Magnetic recording of analog signals through the proposed device is as follows. The analog signal is fed through the input bus 2 to the recording amplifier 1, from which the recorded signal is fed to the weighing filter 6 of the high frequencies and passes through the notch filter 3 to the first, output k of the recording magnetic head 5. The weighing filter b high frequencies separating the high-frequency part spectrum of the recorded signal, air; acts on a level 7 detector. The level detector 7 selects the envelope of the high-frequency part of the spectrum of the signal being fed, which enters the threshold element 8. In the case that the envelope of the high-frequency part of the spectrum of the recorded signal exceeds the threshold level, the threshold element 8 generates a signal from its output to the amplitude modulator 25, to which is also applied the alternating voltage of the high-frequency bias from the output 20 of the erase and bias generator 9. The high-frequency bias voltage in the amplitude modulator 25 is supplied through a voltage divider formed by the first and second resistors 13 and 14 to the non-inverting input of the operational amplifier 22. The gain of the operational amplifier 22 is determined by the feedback circuit formed by the fourth resistor 16 and a field-effect transistor 23, the resistance of which is changed by the signal of the threshold element 8 arriving at its gate through the third resistor 15. The third and fifth resistors 15 and 17 and the second capacitor 12 increase the linearity of the change, the gain of the operational amplifier 22 depending on signal of the threshold element 8. As a result, the output of the operational amplifier 22 through the first capacitor 11 to the first output 4 of the recording magnetic head 5 receives the result of linear amplitude voltage modulation in sokochastotnogo bias signal porogo5159

element 8. In the recording filament head 5, a current is generated, which is determined by summing the recorded signal and the result of amplitude modulation of the bias voltage, which extends the frequency range of the analog signal recorded on the magnetic recording medium while reducing nonlinear distortions. At the same time, the generator 9 for erasing and biasing ensures the pre-erasing of the magnetic recording medium by means of the erasing magnetic head 10.

Claims (1)

Invention Formula A device for magnetic recording of analog signals, containing a recording amplifier, whose input is connected to the input bus, and the output is connected via a notch filter to the first output of a recording magnetic head and connected to the input of a high-frequency weighting filter connected by an output through the level detector to the input of the threshold element, the erase and bias generator connected by the output to the first output erase magnetic head connected to the second output common bus, which is connected to the second output of the recording magnetic head and the first output of the first of the resistors, and capacitors, which is, in order to expand the frequency range of the recorded frequencies of the analog signals, an operational amplifier is connected to it, connected by an output through the first capacitor to the first output of a recording magnetic head and connected with a non-inverting input to the second output of the first resistor and to the first output the second resistor connected to the second output of the erase and bias oscillator; and a field-effect transistor connected to the common bus and connected to the gate via a third resistor with the output of the threshold element, and the input of the operational amplifier is connected to its output through the fourth resistor connected to the field drain transistor and connected via a second capacitor connected in series and a fifth resistor to the gate of the field-effect transistor. Z4i H ± 1