SU1583971A2 - Device for magnetic record - Google Patents

Abstract

The invention relates to the accumulation of information and may find application in magnetic recording. The purpose of the invention is to expand the frequency range of the recording. On the capacitor 8, a total voltage is generated, which is determined by the bias current through the recording magnetic head 1 and the highest frequency of the sound signal received on the input bus 2 of the write current. The total voltage across the trimming resistor 13 is applied to transistors 15 and 16, which, depending on its magnitude, ensures the discharge of capacitors 11 and 12 or their charge through diodes 17 and 18. The charge of capacitors 11 and 12 reduces the bias current through the recording magnetic field. head 1 and a decrease in the total voltage on the capacitor 8. The latter provides a dynamic decrease in the bias current in accordance with the high-frequency part of the spectrum of the recorded sound signal and an increase in its level on the nose body magnetic recording. 2 Il.

Description

The invention relates to the accumulation of information, namely, magnetic recording devices, and is an improvement of the invention in auth st. No. 1304059.

The purpose of the invention is to expand the frequency range of the recording.

FIG. 1 and 2 illustrate possible embodiments of the proposed magnetic recording device.

The device contains a recording magnetic head 1 connected by a first output to the input bus 2 of the recording current and connected by a second output directly to the first output of an adjusted resistor 3 connected by a second output to the input bus 4 of the bias current. The recording magnetic head 1 is also connected by a second terminal directly to the first terminals of the adjustable inductance coil 5 and the first capacitor 6 connected by the second terminals directly to a common bus 7 connected to the first terminal of the second capacitor 8.

The device also contains an additional coil 9 adjustable inductance, directly connected to the first and second conclusions, respectively, with the first output of the recording magnetic head 1 and the second output of the second capacitor 8. The device also contains the first resistor 10, the third and fourth capacitors 11 and 12 and an additional tuned the resistor 13 connected by the first leads to the common bus 7, the second resistor 14 connected by the first lead to the second lead of the recording magnetic head 1, the first and the second transistor s 15 and 16, with different conductivity, and the first and second diodes 17 and 18.

In the embodiment of the device shown in FIG. 1, the emitters of the first and second transistors 15 and 16 are connected to the second output of the first resistor 10, the bases of the first and second transistors 15 and 16 are connected to the sliding contact of the additional trimming resistor 13 connected to the second output of the second output of the additional coil 9 of adjustable inductance, and the collectors the first and second transistors 15 and 16 are connected to the second terminals of the third and fourth capacitors 11 and 12, respectively, and connected to the second terminal of the second resistor 14, respectively, through the first and second diodes 17 and 18, included counter.

In the embodiment of the device shown in FIG. 2, the sources of the first and second transistors 15 and 16 are connected to the second output of the first resistor 10, the gates of the first and second transistors 15 and 16 are connected to the sliding contact of the additional trimming resistor 13 connected to the second output of the second output of the additional coil 9 of adjustable inductance, and the drains first and second tran0

The resistors 15 and 16 are connected to the second terminals of the third and fourth capacitors 11 and 12, respectively, and connected to the second terminal of the second resistor 14, respectively, through the first and second diodes 17 and 18, which are connected in opposite directions.

The operation of the proposed device for magnetic recording is as follows.

The high-frequency bias current flowing through the input bus 4 of the bias current passes through the trimmer 3, through which its value can be adjusted. The bias current does not pass through the adjustable inductance coil 5 and the first capacitor 6, as they form a parallel resonant circuit tuned to the frequency of its first harmonic, but passes through the recording magnetic head 1. The bias current also passes through the additional adjustable inductance coil 9 and the second capacitor 8, since they form a series resonant circuit tuned to the frequency of its first harmonic. In this case, a voltage proportional to the bias current passing through the recording magnetic head 1 is formed on the second condenser 8.

The current of the sound signal coming through the input bus 2 of the write current passes through the recording magnetic head 1 and through the coil 5 of the adjustable inductance, which has a slight resistance at all frequencies of the sound signal. At the same time, at the lower and middle frequencies of the audio signal, the current flowing through the input 5 bus 2 of the recording current practically does not pass through the additional coil 9 of the adjustable inductance and the second capacitor 8, since their resistance at these frequencies significantly exceeds the resistance of the recording magnetic head 1. The second capacitor 8, together with the adjustable inductance coil 5, the additional adjustable inductance coil 9 and the recording magnetic head 1, form a parallel resonant circuit, tuned the first audio signal to a higher frequency. Due to this, the current supplied via the input bus 2 of the recording current forms a voltage at the highest frequency of the audio signal on the second capacitor, which is comparable in magnitude with the bias current.

The total voltage generated on the second capacitor 8 by the bias current and the current of the sound signal goes to the bases or the gates of the first and second transistors 15 and 16. If the total voltage coming from the sliding contact of the additional trimmer resistor 13 is less than the threshold level, the first and the second transistors 15 and 16 are

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in the closed state, and the third and fourth capacitors 11 and 12 are charged, respectively, through the first and second diodes 17 and 18 to an amplitude voltage on the recording magnetic head 1. At the same time, the fully charged third and fourth capacitors 11 and 12 and the first and The second transistors 15 and 16 practically do not affect the magnitude of the magnetizing current through the recording magnetic head 1. If the total voltage on the sliding contact of the additional trimming resistor 13 exceeds the threshold level, then opening the first or second transistors 15 and 16 and discharging through the first resistor 10, respectively, the third or fourth capacitors 11 and 12. Thereafter, the first, third or fourth capacitors 11 and 12 are charged through the second resistor 14 and respectively the first or second diodes 17 and 18, which ensures a decrease in the bias current through the recording magnetic head 1 and a corresponding decrease in the voltage on the second capacitor 8. The latter provides a dynamic decrease in the bias current in accordance with with the high-frequency part of the spectrum of the recorded audio signal and an increase in its recording level on the magnetic recording medium.

Using bipolar transistors (Fig. 1) as the first and second trans /

Resistors 15 and 16 provide a high performance of the proposed device for magnetic recording, and the use of field-effect transistors (Fig. 2) reduces its power consumption.

Claims (1)

Invention Formula The device for magnetic recording of aut. St. No. 1304059, characterized in that, in order to expand the recording frequency range, a first resistor, a third and a fourth capacitor, and an additional trimming resistor connected by first pins to a common bus, a second resistor connected by a first pin to the second output of a recording magnetic head are inserted into it. , the first and second transistors with different conductivity, and the first and second diodes, with the emitters or sources of the first and second transistors connected 0 to the second output of the first resistor, the base or the gates of the first and second transistors are connected to a sliding contact of an additional trimming resistor connected by a second output to the second output of an additional coil of adjustable inductance, and the collectors or drains of the first and second transistors are connected to the second terminals of the third and third respectively the fourth capacitor and connected to the second output of the second resistor, respectively, through the first and second diodes connected in opposite. No 77 $ 182 / 5 76 Fb