SU851484A1 - Device for measuring speed-up time of magnetic tape - Google Patents

Description

(54) DEVICE FOR MEASURING THE TIME OF ACCELERATION OF A MAGNETIC TAPE

I

The invention relates to instrumentation and can be used as a device with which it is possible to determine the time of acceleration of a magnetic tape in a tape drive mechanism of a magnetic recording apparatus.

A device for measuring the acceleration time of a magnetic tape is known, which comprises a tape triggering unit, a time interval meter, a number of counters and logic circuits. In such a device, several periods are recorded on a carrier, in particular on a magnetic tape, where each period is filled with pulses received from the reference frequency generator 1.

Taking into account that the acceleration time is usually small, the sensitivity of such a device is not high enough (after all, it is necessary to reproduce at least several periods). Those. an objective assessment in this case is not respected, which further affects the reliability of the recorded and reproduced information.

The closest to the present invention is a device for measuring the acceleration time of a magnetic tape, which contains a tape mechanism, in which a channel for reproducing information from a magnetic tape, a push button switch associated with a tape mechanism, a recorder and a reference frequency generator 2 are installed. but in the event of transient processes, when a change in the speed of movement of a magnetic tape occurs, its sensitivity also turns out to be insufficiently high, which reduces the functionality the total capabilities of the device as a whole.

The purpose of the invention is to increase the sensitivity of the device and the expansion. its functionality by implementing the possibility of registering transients with changes in the velocity of the magnetic tape.

This goal is achieved by the fact that a device for measuring the acceleration time of a magnetic tape, containing a tape mechanism, in which a channel for reproducing information from a magnetic tape is installed

 ribbons, a pushbutton switch associated with a tape machine, a recorder and a reference frequency generator, are connected in series between the output

the playback channel and one of the recorder inputs by a frequency multiplier, a modulator, a bandpass filter, a calibrated filter and a phase shift to voltage converter, while the reference frequency generator is connected to the second modulator input, the output of the band pass filter is with the second input of the phase shift converter in the voltage source button, and with the second input of the recorder.

The drawing shows a block diagram of the proposed device.

In the tape engine 1, an information playback channel 2 is installed, which, through serially connected multiplier 3 frequencies, modulator 4, band-pass filter 5, calibrated filter 6, and phase shift to voltage converter 7 is connected to recorder 8, with a second input connected to a button switch 9. A generator 10 of the reference frequency is connected to the second input of the modulator.

A pushbutton switch 9 is used for a quick start of the tape mechanism and at the same time the recorder. After the usual amplification, the signal recorded on a magnetic tape (not shown) is multiplied. But the multiplication factor itself is the limit and is no more than three or four units, since otherwise the error occurs exactly at the multiplication stage. The multiplied frequency signal is then modulated by the reference frequency from the generator 10, with the result that the intermediate frequency signal is produced at the output of the filter 5 modulated in accordance with the change in the speed of movement of the magnetic tape. Thus, the converter 7 receives two signals, one of which is direct from the output of filter 5, and the second from the output of the calibrated filter 6. If a phase mismatch occurs between these signals, this is recorded in the recorder 8. By calibrating the recorder accordingly obtain data on the time of acceleration of the magnetic tape in the forward direction and when reversing it, as well as on the value of the reverse acceleration, i.e. about braking ..

The use of the proposed device makes it possible to obtain an objective idea of which section of the magnetic tape should be excluded from the work, since during acceleration and deceleration, the longitudinal information recording density may exceed the permissible norms.

Claims (2)

Invention Formula A device for measuring the time of acceleration of a magnetic tape, containing a tape mechanism, in which a channel for reproducing information from a magnetic tape is installed, a button switch associated with a tape mechanism, a recorder and a frequency generator, characterized in that, in order to increase its sensitivity and extending functionality by enabling transient registration with changes in speed 5 of the magnetic tape motion, it is provided with series-connected between the output of the playback channel and one of the recorder inputs a frequency multiplier, a modulator, a band-pass filter, a calibrated filter and a phase-to-voltage converter, while the reference frequency generator is connected to the second input of the modulator, the output the band-pass filter is with the second input of the phase-shift-to-voltage converter, and the push-button switch with the second input of the recorder. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 369541, cl. G 04 F 11/08, 1970. 2. USSR author's certificate No. 352305, cl. G & B 15/18, 1970 (prototype