SU1610321A1 - Apparatus for measuring tension of tape - Google Patents

Abstract

The invention relates to the field of instrumentation and can be applied when measuring the belt tension with high accuracy, for example, in magnetic recording apparatus. The invention makes it possible to increase the accuracy of measuring the belt tension by using a precision electromechanical feedback device that implements a compensation measurement method. The tension value is measured by changing the frequency of a self-oscillating system connected with a tape by force interaction through a charged electrode, the plane of which is parallel to the plane of the tape. The self-oscillating system includes a movable system in the form of a roller with an electrode attached to it using a rocker arm, a position sensor of the movable system, the output of which is connected to the control input of a key element, a magnetoelectric converter made in the form of a permanent magnet rigidly mounted on the movable roller systems, and feedback windings mounted on the housing at opposite poles of the permanent magnet. 3 il.

Description

The invention relates to instrumentation and can be used when measuring the belt tension with high accuracy.

The purpose of the invention is to increase the measuring languor of the ribbon.

FIG. 1 shows a block diagram of the proposed device; in fig. 2 is a functional diagram of the device in FIG. 3 is a diagram of the electrostatic interaction forces of the electrode and the tape.

The device contains a flat electrode 1, mounted on one end

the rocker arm, at the other end of which the shutter 3 is mounted. The rocker arm 2 is fixed on one of the ends of the roller C, installed in supports 5 and 6, with the possibility of movement around its longitudinal lane, which provides movement of the curtain 3 in the gap between the pairs installed and coaxially. On the housing of the device are radiators 7 and 8 and photoreceivers 9 and 10 datomic 11 positions. The permanent magnet 12, rigidly mounted on the roller, roller 4 and the rocker arm 2 with the elements fixed on it, forms the ground

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Vision system 13. The reverse windings 14 and 15 are fixed on the device body under opposite poles of permanent magnet 12 and together with the latter form a magnetoelectric converter 16. The control inputs of the key element 17 are connected to the outputs of the photodetectors 9 and 10 of the position sensor 11. To the output of the key element 17 are connected in parallel connected windings And 15 and feedback. Emitters 7 and 8, photodetectors 9 and 10, windings 1A and 15 of the feedback, and key element 17 are connected to the terminals of a stabilized DC source 18.

A recording device 19 made in the form of a frequency meter is connected to the windings 14 and 15 of the feedback. The positive terminal of the constant voltage source 21 is connected to the flat electrode 1, and the negative terminal of the source 21 through the resistor 20 is connected to the tape 22. The electrode 1 is fixed on the rocker arm 2 so that its plane is parallel to the plane of the tape 22.

The device works as follows.

In the initial position, the shutter 3 (Fig. 1) blocks the radiation flux from one of the emitters, for example, the emitter 8. When the power is supplied to the emitters 7 and 8 and the photoreceivers 9 and 10, the photodetector 9 operates, the signal from which goes to one of the control inputs the key element 17, as a result of which g the winding 15 of the feedback of the magnetoelectric converter 1b receives current from the stabilized DC source 18. In this case, in the magnetoelectric converter 1b, due to the interaction of the magnetic field of the DC magnet 12 with the Maximal field created by the DC current passing through the feedback winding 15, a moment occurs around the longitudinal axis of the roller 4, so that the mobile system 13 passes to the position in which the shutter 3 blocks the radiation flux of the emitter 7, but the radiation flux of the emitter 8 opens. Then the photodetector 9 closes and the photoreceiver 10 opens. The signal from the photodetector 10 is fed to the second input

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key element 17, after switching which current from stabilized constant current source 18 enters feedback feedback coil 14 of magnetoelectric converter 16, as a result of which a moment opposite to the previous one will be created in the latter. Next, the switching process will repeat, resulting in the mobile system 13 of the device and, therefore, the flat electrode 1 will oscillate with some constant amplitude and frequency. In this case, the device 19 will register a sequence of bipolar pulses of constant frequency s.

When a different-voltage electrical voltage is applied from the source 21 to the flat electrode 1 and to the tape 22, an electrostatic interaction force F arises between them which is proportional to the magnitude of the applied voltage and inversely proportional to the square of the distance S between them. The presence of the force Fg has a damping effect on the moving system 13. On the other hand, the counterbalancing forces F occur due to the force FJJ of the belt tension F (Fig. 3). The electrostatic interaction diagram of the electrode and the tape (Fig. 3) implies the necessity of parallelism of the plane of the electrode 1 to the plane of the tape 22. When the force F changes (with source voltage 21) a new equilibrium state of the tape system — the electrode is established by changing distance, which leads to a corresponding change in the force Fjc and the magnitude of the damping effect on the moving system 13, which, in turn, leads to a change in the frequency of self-oscillations of the moving system 13 fixed by the device 1 9.

Claims (1)

Invention Formula A device for measuring the tension of a tape, containing a high-voltage source of voltage, to the poles of which an electrode is connected and through a limiting resistor and pressure roller a tape, a key element and a recording device, characterized in that KlkmeBoy 3 fHfHm ig.2 magnetic mngo -  electrode Fig.Z