RU2107952C1 - Device for magnetic recording of analog signals - Google Patents

Abstract

FIELD: information storage equipment. SUBSTANCE: device has high-frequency bias current generator 1, serial circuit of recording amplifier 2, weighting low-pass filter 3, full-wave rectifier 4, accumulating amplifier 5 which is connected to initial level generator 6, and high-frequency bias current modulator 7. High- frequency bias current generator 1 is connected to high-frequency bias current modulator 7. Rejection unit 8 is designed as rejection filter 10 and high-pass filter 11. Output of recording amplifier is connected to rejection filter 10 of rejection unit 8. Output of high- frequency bias modulator 7 is connected to high-pass filter 11 of rejection unit 8, which output is connected to recording magnetic head 9. EFFECT: decreased noise level both in case of signal presence and signal absence. 4 cl, 1 dwg

Description

 The invention relates to a means of accumulating information, and in particular to devices for magnetic recording of analog signals.

 A device for magnetic recording of signals is known, comprising a high-frequency bias current generator, a recording amplifier connected in series, a weighing filter, a rectifier, a high-frequency bias current modulator, a magnetic head and a notch block with two inputs and one output, connected by its inputs to the output of the recording amplifier and the output of the modulator current of high-frequency magnetization, and the output is connected to a recording magnetic head, and the generator of high-frequency current is magnetized of magnetization is connected with a high-frequency magnetization current modulator (SU, Copyright certificate N 1597901, class G 11 B 5/027, 1990).

 A disadvantage of the known device is the increased level of non-linear distortion and structural noise of the magnetic recording medium, as well as the increased noise level in the absence of a signal.

 The technical result of the invention is to reduce the level of nonlinear distortion and noise both in the presence of a signal, and in its absence.

 To achieve the technical result, the proposed device for magnetic recording of analog signals contains a high-frequency bias current generator, a recording amplifier, a weighing filter, a rectifier, a high-frequency bias current modulator, a recording magnetic head and a notch block with two inputs and one output, connected by its inputs to the output recording amplifier and the output of the modulator of the current of high-frequency magnetization, and the output connected to the recording s magnetic head, high-frequency current generator connected to the modulator bias high frequency bias current. The device is equipped with an initial signal level generator and a summing amplifier connected between the input of the high-frequency magnetization current modulator and the output of the rectifier made according to a half-wave circuit.

 The notch block is made in the form of a notch filter and a high-pass filter.

 The weighing filter is made in the form of a low-pass filter formed in the form of an integrating RC chain with a constant of 37 μ / s when using a magnetic tape with a working layer of iron oxide, designed for a tape speed of 4.76 cm / s.

 The drawing shows a block diagram of the proposed device.

 The device comprises a generator 1 of a high-frequency bias current, a recording amplifier 2 connected in series, a weighing filter 3 of a low frequency, a half-wave rectifier 4, a summing amplifier 5 connected to an initial level generator 6, a modulator 7 of a high-frequency bias current, recording a magnetic head 9.

 The high-frequency magnetization generator 1 is connected to the high-frequency magnetization current modulator 7. The notch block 8 is made in the form of a notch filter 10 and a high-pass filter 11.

 The output of the recording amplifier 2 is connected to the notch filter 10 of the notch unit 8. The output of the high-frequency magnetization modulator 7 is connected to the high-pass filter 11 of the rejection unit 8. The notch filter 10, designed to decouple the recording amplifier 2 from the bias circuits, is formed either by an oscillating circuit consisting of a capacitor and inductance, or by an RC circuit (not shown).

 A low-pass filter 3 is formed by a capacitor 12 and a resistor 13. A resistor 13 is connected between the output of the amplifier 22 and the input of the rectifier 4, and a capacitor 12 is connected between the input of the rectifier 4 and the common bus.

 Magnetic recording in the proposed device is as follows.

 An analog signal is fed to the input of the recording amplifier 2, passing through which it undergoes frequency correction and power amplification to obtain a standard amplitude-frequency characteristic of the magnetic tape short-circuit flow.

 From the output of amplifier 2, the signal is supplied simultaneously: through the notch filter 10 of the rejection unit 8 to the recording magnetic head 9, and through the weighing filter 3, which selects the low-frequency part of the spectrum of the recording signal, to the input of the half-wave rectifier 4. From the output of the rectifier 4, the signal is fed to the first the input of the summing amplifier 5, the second input of which receives a signal from the generator 6 of the initial level.

 Setting the initial level allows you to match the modulation characteristic of the modulator 7 of the high-frequency magnetization current with the magnetization characteristic of the magnetic tape.

 From the output of the summing amplifier 5, the signal is fed to the first input of the modulator 7 of the high-frequency bias current, the second input of which receives current from the high-frequency bias generator 1. At the output of the modulator 7 of the high-frequency bias current, an amplitude-modulated high-frequency bias current is generated. This current, through a high-frequency decoupling filter 11, is supplied to the recording magnetic head 9. The decoupling filter 11 is designed to prevent the passage of the recording current from the recording amplifier 2 to the high-frequency magnetization current modulator 7.

 When using a magnetic tape with a working layer of iron oxide, designed for a tape speed of 4.76 cm / s, used in cassette recorders - designated IEC 1, the weighing filter 3 has a time constant of 37 μ / s.

Claims (4)

 1. A magnetic recording device for analog signals, comprising a high-frequency magnetizing current generator, comprising a high-frequency magnetizing current generator, a recording amplifier, a weighing filter, a rectifier and a high-frequency magnetizing current modulator, recording a magnetic head and a notch block with two inputs and one output, connected by its own inputs with the output of the recording amplifier and the output of the modulator of the current high-frequency magnetization, and the output connected to the recording guide the magnetic head and the high-frequency current generator is connected to the bias current of high-frequency bias modulator, characterized in that it is provided with an entry level signal generator and its associated summing amplifier connected between the input current and the bias RF modulator output of the rectifier configured by a full-wave circuit.  2. The device according to claim 1, characterized in that the notch unit is made in the form of a notch filter and a high-pass filter.  3. The device according to claim 1, characterized in that the weighing filter is made in the form of a low-pass filter.  4. The device according to claim 3, characterized in that the weighing filter is made in the form of an integrating RC chain with a constant of 37 μs when using magnetic tape with a working layer of iron oxide, designed to operate at a speed of 4.76 cm / s.