SU746711A1 - Device for monitoring the recording of information onto magnetic tape - Google Patents

Description

(54) DEVICE FOR CONTROL OF RECORDING INFORMATION ON A MAGNETIC TAPE

one

The invention relates to instrumentation, in particular to magnetic recording, and can be used to monitor the performance of tape drives.

A device is known for monitoring the phase shift between reproduced signals, in which a sinusoidal signal is recorded on a magnetic tape and after a fixed number of periods a pulse mark. The phase shift is determined using an oscilloscope based on the result of a reproduced sinusoidal signal and the marks 1 pulses.

The presence of a pulse generator tags, create inconvenience in operation and increase the time spent on monitoring the performance of magnetic drives. ..-- those.

The closest in technical essence is a device comprising code and clock reproduction heads, each of which is connected through a corresponding driver to the first and second inputs of a code and clock separation unit, two outputs of which are connected to the first and second comparison blocks, respectively. In addition, the device also contains a generator, a key, a counter, a decoder, triggers and logic elements. The accuracy of the control is determined by the minimum duration of the error pulse that triggers the trigger of the display unit 2.

The mismatch between pulses by an amount shorter than the duration of the starting pulse is not controlled by the display unit, since such a device has

10 greater error of control. In addition, this device is quite difficult.

The purpose of the invention is to simplify the device and improve the accuracy of control.

The goal is achieved by the fact that the device containing the reproduction heads of code and clock signals, each of which is connected through the corresponding driver to the first and second inputs of the code and clock separation unit, the two outputs of which are connected respectively to the first and second comparison blocks, is equipped with zero an organ, as well as two electrical circuits, each of which contains an amplifier connected in series, a differentiator.

mismatch pulse forming unit and indicator, while the amplifier inputs are connected to the outputs of the comparison units, the indicator outputs are connected to the zero-organ inputs, and the second input of the first comparison unit is connected to the second input of the code and clock separation unit, the first input of which is connected to the second input the second unit of comparison.

Instead of a reference frequency generator, clock pulses are used with sync syncing on a magnetic tape.

FIG. Figure 1 shows the electrical circuit diagram of a device for monitoring tape drives; in fig. 2 and 3 show signals on reference elements.

A magnetic tape drive includes a multi-track magnetic tape 1, a magnetic reproduction head 2, a preamplifier 3, a pulse shaper 4. The device for monitoring tape drives contains a block 5 for separating code and clock pulses, in each of the two-channel comparison elements b, amplifiers 7, differentiating circuits 8, drivers of misalignment pulses 5, display elements 10, null-organ I, showing the magnitude of the error .

The device works as follows.

To control the mismatch between code and clock pulses on magnetic tape 1, sinusoidal signals are recorded on each track, which are reproduced by magnetic heads 2. Signals are amplified in amplifiers 3 and fed to block 4, where rectangular pulses are formed from sinus / 1 signals. . The generated code and clock pulses arrive at the inputs of separation unit 5, here the exponential pulses from the leading edges of the code and clock pulses are formed, these pulses arrive at the comparison elements 6.

If there is a pulse mismatch, i.e. an exponential impulse (clock or code) comes before one of the comparison elements before a rectangular (code or clock) pulse, then at the output of the comparison element, the needle Shpulse has a duration equal to the magnitude of the error (Fig. 2). At another comparison element, an exponential impulse will come later than a rectangular one and in that case the output of the comparison element is a signal ofcyTCTByeT (Fig. 3). The mismatch needle pulse is amplified by the amplifier 7 and supplied

on the differentiating chain 8, which passes from the leading edge of the needle pulse, exponential impulse is generated that is able to start the pulse shaper 9 pulses. The formed rectangular impulse is supplied to the display element 10, which detects the presence of a mismatch. The zero-organ 11 is included in the output circuits of the display elements and measures the potential difference between the output points of the test channel for the advance of the clock pulse from the code channel and the test channel for the lag of the clock pulse from the code pulse.

Using clock pulses as a reference frequency generator and comparing test pulses with code-based comparison elements with pulse collector pigmentation, and then generating a rectangular pulse of a duration sufficient for indication to form a mismatch needle pulse, it simplifies the design and improves the accuracy of control and reliability of the device.

Claims (2)

1.Avtbrskoe certificate of the USSR No. 528609, cl. G 11 B 27/36, 1975. 2. USSR author's certificate No. 558305, cl. G 11 V 27/36, 1976 (prototype). 2 Fi.a. 2 rrr tf 746711 fa.2.3