SU1615800A1 - Device for monitoring slanting of magnetic tape - Google Patents

Abstract

The invention relates to instrument making can be used in a separate control apparatus for measuring the maximum skew value of a magnetic tape. The proposed device contains magnetic heads 1.2 playback, amplifiers - drivers 3,4, shapers 5,6,7 pulses, triggers 8,9,10, stable frequency generator 11, dividers 12, 13 frequencies, reversible binary counter 14, counter 15 pulses, decoders 16, 17, element 18, registers 19, 20, trigger block 21, LED scale 22, inverter 23 and individual indicators 24, 25. Improving skew control accuracy by providing an indication of its maximum values by memorizing peak skew values block 21 triggers on a time sufficient to visually fix them on a linear scale of 22. 1 sludge.

Description

The invention relates to industrialization, and in particular to magnetic recording technology, and can be used in built-in tools and separate control equipment for measuring the maximum skew value of a magnetic recording tape carrier.

The purpose of the invention is to increase the accuracy of control of the skew of the magnetic tape by indicating the maximum values of the skew.

The drawing shows a functional diagram of the device.

The device for controlling the skew of the magnetic tape contains magnetic heads 1 and 2 of the reproduction, amplifiers-shapers 3 and 4 of the reproduction signal, drivers of 5-7 pulses, triggers 8-10, a stable frequency generator 11, frequency dividers 12 and 13, a reversible binary counter 14, pulse counter 15, decoders 16 and 17, element 18, registers 19 and 20, trigger block 21, LED scale 22, inverter 23 and individual indicators 24 and 25 (LEDs) connected in a certain way.

The device operates as follows.

Signals are reproduced from the two extreme tracks of the magnetic tape previously recorded on it synchronously with one Multi-track unit of recording magnetic heads. In this case, the recording condition is such that the clock interval T between adjacent level differences of the recording signal is two times greater than the maximum skew value.

The output pulse of the first channel sets the frequency divider 12 to zero and the counter 15 switches the trigger 8 to a single state, which sets the Summing mode of the counter 14, and sets the trigger 9 to zero to enable the count of output pulses.

The counter 14 in the summation mode is only filled up to half (0.5 T), after which there is a switch from the Summation mode to the subtraction. If during the Subtraction the pulse of the second channel was not received, then after 16 positive drops of the output signal of the frequency divider 12, the operation mode of the counter 14 is changed to summation. Moreover, the middle of the 32nd period of the output signal of the divider 12 is associated with the nominal location of the reproduction pulse of the first channel. During the reversal of the counter 14 in the middle of the clock playback interval, a pulse is generated at the output of its fifth digit, the duration of the measuring period of the output signal of the frequency divider 12.

When the corresponding pulse of the second channel arrives after the playback pulse of the first channel, along the edge of this pulse, the contents of counter 14 — binary code 00010 of the third LED on the scale 22 — are recorded in register 19. This pulse is reset to counter zero 10, counter 15, and trigger 9 is switched to the single state . At the same time, its output signal in the form of a high voltage level is stopped due to the measuring intervals in the counter 14.

The state of the register 19 through the decoder 17 switches the third trigger of the block 21 and, accordingly, the third LED of the scale 22, after which the trigger is reset to the initial state after 1 - 2 with the output 20 pulse of the driver 7, the pulse repetition rate at the output of which is set by the frequency divider 13.

If the playback pulse of the second channel is ahead of the pulse of the first channel corresponding to it25 and comes, in particular, after the 28th switching of the counter 14, when the binary code 00100 of the fifth LED of the scale 22 is set at its outputs, then register 19 records the contents of the pulse 30 of this pulse counter 14, which in this case is also a binary code of the bias value. The skew sign is indicated by a separate indicator 24, which is controlled by trigger 35 10. When the pulses of the first playback channel drop out, the reproduced pulses of the second channel record the previous skew value in register 19.

In the absence of playback signals of both channels, a signal is generated at the output of the counter 15 pulses, which switches the trigger 9 to a single state. At the same time, the counter 14 is locked and the indicator 25 turns on 45, indicating that the skew measurement is not performed.

Claims (1)

Claim A device for controlling the skew of a magnetic tape, comprising a series of connected first magnetic heads, an amplifier-pulse shaper and a first trigger, series-connected second magnetic heads, an amplifier-driver and pulse shapers, a second trigger, a stable frequency generator, a first frequency divider, and a reversible counter , a pulse counter and a first decryptor and an And element connected in series, characterized in that, in order to improve the accuracy of controlling the skew of the magnetic tape at the expense of t indication of the maximum skew value, it includes the first register, the second decoder, the second register, the 5 block of triggers and the LED scale connected in series to the stable frequency generator, the second frequency divider and the third pulse shaper, the output connected to the installation trigger block input, the first indicator connected to the output of the third trigger, the first input of which is connected to the first control input of the reverse counter with the output of the first trigger, an inverter connected to the control input of the second register, and the input to the control input of the first register, the second input of the third trigger, the setup input of the counter of 20 pulses, the first input of the second trigger and the output of the second pulse shaper, and the second indicator connected to the second control input of the reversible counter and the output of the second trigger, the second input of which is connected through the pulse counter to the output of the last bit of the reversible counter, while the output of the first form pulse changer 10 is connected to the third input of the second trigger and to the installation inputs of the reverse counter and the first frequency divider, the input of which is connected to the output of the stable frequency generator, and the output to the counting input 15 of the reverse counter and the inverse input of the element And, the output connected to the second input of the first trigger, and the inputs of the first decoder are connected to the outputs of the bits of the reversible counter.