SU111790A1 - Device to compensate for the change in the size of the gap between the magnetic head and the sound carrier - Google Patents

Description

The invention relates to the technique of contactless magnetic recording, OcHOBHoii the disadvantage of this recording lies in the fluctuations of the output voltage of the reproducing head, due to non-periodic changes in the distance between the magnetic head and the sound carrier, which is usually used as a metal non-magnetic drum, covered with a ferromagnetic layer material. These variations in distance are caused by the inaccuracies made when making the drum and the wear of its bearings. The magnitude of the output voltage fluctuations can reach several decibels at a frequency of 10 kHz and a linear velocity of the sound carrier of about 2 ms.

Such oscillations may not be acceptable for a number of devices (for example, for a magnetic rsverberator). The described device makes it possible to compensate for these fluctuations in the output voltage of the magnetic head.

The principle of operation of the device is illustrated in the drawing, where at some distance from the acoustic carrier /, on which 1 ~ 10 is recorded, the frequency is about 3-5 kHz with a CONSTANT amplitude, the additional magnetic reproducing head 2 is pressed. The voltage of the head 2 is amplified by the amplifier 3 and is fed to the detector 4, which resists a load resistance 1e in the anode circuit.

5, bypass capacitor

6, on which SA voltage develops. Contrast, class 5 is included in the control grid of the reactive lamp 7, which, in turn, is included in the inter-stage communication circuit of the reproduction amplifier 8 or in the negative feedback circuit of the amplifier as an element, change 1, its frequency response at high frequencies, which is affected by the effect of a change in the size of the gap between the head and the sound of the TSLEM.

Subject invention

Device; i iasb .: compensating for the effect of a change in the size of the gap between the -MaJ & head and sound carrier,} ,,. chz sv / prohodnya iazheniye magnetic head, consisting nz additional reproduction of the main sys tem head, amplifier, detector and reactive lamna, so that in order to automatically change the frequency frequency (the characteristics of the power amplifier of the main magnetic head in the high-frequency region, it includes, as corrections for the element of the inter- communication communication or negative feedback, the main amplifier of the amplifier, reactive lamina, equivalent parameters to The device is controlled by the internal voltage of the donor side. Take control of the magnetic head of the magnetic head.