SU555434A1 - Device for measuring fluctuations in the speed of movement of a magnetic tape - Google Patents

Description

(54) DEVICE FOR MEASURING VIBRATIONS OF THE MOTION RATE MAGITIC TAPE

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The invention relates to instrumentation, in particular, to a device for measuring fluctuations in the speed of movement of a magnetic tape used in magnetic recording equipment.

A device is known which makes it possible to measure the speed of movement of a magnetic penta made with a magnetic head, a pulse generator, an amplifier, a driver and an I trigger. This device is quite reliable in operation, but does not always allow to obtain the required accuracy of the output results.

A more accurate operation is a device made in the same way with an impulse generator, but with a counter, start and stop circuits, in which triggers, C1, are used (matches, performing the function of AND-NOT circuits, and register the encoder and the decoder 2j. However, the accuracy of such a device is achieved due to its considerable complexity, which is not always acceptable for a particular production.

The closest in technical essence to the present invention is a device for measuring fluctuations in the speed of movement of a magnetic tape, comprising a magnetic head connected through an amplifier to a pulse shaper, a register, a trigger, a main AND-N circuit, a reference frequency generator, a main counter and a recording device But this device

does not have a sufficiently high accuracy in the measurement. In addition, from this device, it is difficult to enter the received data into an electronic digital computer (EECM).

The purpose of the invention is to improve the accuracy of measurements and the possibility of inputting the obtained data into an electronic digital computer.

Achieving this goal is accomplished with by supplying the device with an additional counter connected between the output of the main NAND circuit and the first input of the trigger, as well as an additional circuit

YUL AND-NOT included between the generator.

the reference frequency and the main counter, while the pulse shaper is connected to the second trigger input and to the register installed between the main counter and the registering device, the second trigger output is connected to the additional AND-NOT circuit and the second input of the main counter, and the main circuit inputs AND -PUs are connected to the trigger outputs and

reference frequency generator.

The drawing shows the flowcharts

described device.

The signal recorded earlier on magnetic tape 1 is reproduced by magnetic head 2 and through amplifier 3 and shaper 4 is fed to trigger 5. Electric trigger is connected through AND-HE 6 with counter 7, as well as with counter 8 and AND-HE 9. The counter 8 through the register 10 is connected to the registering device 11, and the circuit 9 is connected to the generator of the reference frequency 12.

The signal reproduced from the magnetic tape after amplification and shaping switches the trigger 5, and then the signal from the trigger opens the AND-NOT 6 circuit, which, as a matter of fact, generates pulses from the generator 12 to enter the counter 7. With the filling of this counter selected, the trigger goes to the zero state and circuit 6 closes. At the same moment, the switch 8 is also transferred to the zero state by the trigger, and then the AND – NE scheme 9 is opened. After this, the pulses start to flow already to the counter 8. The next pulse reproduced from the magnetic tape switches the trigger again, closing this circuit 9, and a register is produced to signal to store the readings of counter 8.

In the event of oscillations in the speed of movement of the magnetic tape, the period of the reproduced signal will vary, in which case the number of pulses in the counter 8 will correspond to a certain part of the period of the pulse. The delay time of a signal at the output of counter 8 is

almost constant, and in the interval of this time, the measurement results are recorded in a recording device 11, which can be an EVOM input unit

The accuracy of measurements when using the proposed device increases almost in order.

Claims (3)

1. Author's certificate No. 437O1S, M. Cl. G01 P 3/66, 1972. 2. US patent number 3829893, cl. 36O-73, 1974. 3. Author's certificate No. 418898 M. Cl. Gil 27/36, 1972 (prototype).