SU435556A1 - DEVICE OF REVERSE OF A MAGNETIC LENTYN P T 'B (^ fi,'; s :: bT: ^! I> & tSAuavf l '> &,' U - Google Patents

Description

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The invention relates to the field of instrumentation, in particular to a tape mechanism 1M for recording magnetic recording and reproducing equipment.

There are known devices for rewinding magnetic tape, consisting of a reeling and braking electric motors with sequential excitation and an amplifier. In these devices, the voltage of the side motors is modulated by pulses that are removed from the tension sensor.

The short-lasting known device is the presence of a tension sensor and its mechanical contact with the tape, the complexity of the adjustment device, and greater sensitivity to the effects of mechanical loads.

The purpose of the invention is to ensure three-way rewinding of a magnetic tape without the use of sensors in the case when DC engines with series excitation are used as tank engines.

This is achieved due to the fact that in the proposed device, the amplifier pitch is connected to the winding of the reeling engine, and the output is connected to the braking collector.

In the drawing. Depicts the proposed device rewind the magnetic tape.

It includes reeling engine 1, power 2 and a braking engine 3.

In order to properly place the tape in the rewind mode, it is necessary to maintain a certain ratio between the speed of the tape transport and the belt tension. The angular velocity, torque, and braking torque of engine 1 are determined by:

w - b (1); M cJ «(2); M, FR (3), M

where M -1m is about rotation; Jm - braking torque; M - angular velocity; and - engine supply voltage; / - current through the motor core winding; F is the tension force of the tape, determined by the friction force of the tape in the path to the torque; engine torque; R is the radius of the engine ribbon roll; a, b, c are constant coefficients. From the ratios (1, 2, 3) it can be seen that the angular speed of the reeling engine 1, when the roll radius is minimal, and the tension force is limited by the tape deformation, can be set by selecting the appropriate motor supply voltage 1. At the same maximum roll per engine 1 the maximum braking torque will be effective, resulting in a slowing speed.

In the proposed device, when rewinding a tape from a roll positioned on the axis of the braking motor 3, to a roll on the axis of the reeling motor il, an increase in the torque causes an increase in the voltage drop across the winding, the signal from which is fed to the amplifier 2, causing a decrease feeding the braking motor 3, and hence reducing the belt tension.

With an infinitely large gain factor, the coupling circuit will maintain the current through the reeling engine 1 and the torque M (2) constant, and the tension force of the belt will vary according to the law (3): R

Linear speed D | vizheni tape, equal to

V wff - (, will linearly increase, since “ayration of U and. Moment M are constant, and the radius of the coil increases from the beginning to the end.

Thus, it is possible to choose such a gain, at which both the tension and the linear speed of the tape movement from the beginning to the end of the roll decrease, and the quality of its laying is preserved.

Subject invention

A tape rewinder device consisting of a reeling and recharging electric motors with sequential excitation and an amplifier, characterized in that, in order to obtain a high-quality tape mounting on a roll, the input of the amplifier is connected to the excitation winding (reeling engine, and the output from the collector.

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