SU561999A1 - Device for measuring transverse displacement values of a moving magnetic tape - Google Patents

Description

one

The invention relates to the field of instrumentation and can be used directly in magnetic recording equipment.

A device is known for controlling the position of a magnetic tape during its movement. In a tape-recording mechanism of a magnetic recording apparatus (1), made with two heads having different lengths of working gaps, amplifiers, converters, encoder, decoder, recorder and a number of logical and switch your schemes.

However, this device is difficult to operate, since its maintenance requires highly qualified personnel.

When the device is simplified by using an electromagnet with a moving rod connected with a spring-loaded lever in contact with the magnetic tape, the measurement accuracy (2) is reduced.

The closest to the invention in its technical essence is a device for measuring the lateral movement of a moving magnetic tape, which contains a magnetic head with forward and inclined working clearances, each of which interacts with a separate winding connected with an autonomous amplifier-shaper, nerve and second trigger connected to the third trigger, a reference frequency generator, nerve and second delay blocks, and a recording device (3).

However, this device also does not have a sufficiently high measurement accuracy and, moreover, does not allow direct input of the data obtained during measurement into an electronic-nifra computing machine (PC).

In order to increase the accuracy of measurements and make it possible to directly enter the data obtained in the measurement into the digital computer, the proposed device is equipped with the first AND –NE circuit, the various inputs of which

connected to one of the amplifier-shapers and to the output of the first trigger, and the output to the first input of the third trigger; serially connected by the second circuit IS-NOT, the first counter and register connected between the outputs of the third trigger, the generator of the reference frequency and the input of the recording device; connected in series by the third NAND circuit and the second counter connected between the outputs

the second trigger, the reference frequency generator, the combined inputs of the delay blocks, the second input of the third trigger, and the first input of the first trigger, while the output of the first delay block is connected to the second

inputs of the first trigger and the first counter.

and the output of the second delay unit is with the second register input.

The drawing shows a block diagram of the described device.

The signals from magnetic tape 1 are reproduced by means of magnetic head 2 having straight 3 and inclined 4 working clearances. The working clearances interact with the winding 5, and the key through the amplifier-shaper 6, the first AND-NOT circuit 7, the first trigger 8, the third trigger 9, the second circuit AND-NOT 10, the first counter 11 and the register 12 to the recording device 13, and with the winding 14, connected via the amplifier-shaper 15, the second trigger 16, the third AND-NOT circuit 17, the second counter 18 and the second delay unit 19 to the second input of the register 12.; The first delay unit 20 is connected to the first counter And, and to the second input of the trigger 8, ia, the generator of the reference frequency 21 is connected simultaneously with the second and third circuits AND- .HE 10 and 17.

Due to the fact that the signal on the tape is recorded by heads different in the direction of the working gap (i.e., the presence of two windings suggests that two heads are assembled in one case), then in the playback mode and there will be a transverse movement of the moving magic tape a shift in the signal relative to the inclined gap occurs, i.e., the amplitude of the transverse oscillations will be directly proportional to the temporal mismatch of signals coming from different head windings. After amplification and formation of a sigal from winding 5, using circuit 7, sets trigger 9 to a single state, circuit 10 opens and, through the generator 21, emulses flow to counter I. Signals from winding 14 also amplify and form and set to single state the trigger 16, which allows the circuit 17 to open and pass pulses from the generator 21 across the counter 18. After the selected filling mode, this counter sets the triggers 8, 9 and 16 to the zero state. The trigger 16 prohibits the passage pulses into counter 18, and trigger 9 into counter 11. The number of pulses from counter 18 multiplied by the signal period of the generator 21 corresponds to the delay time of the signal of that channel, which relates to the winding interacting with the cyclical working gap.

The result of measurements from the register and the registering device is entered into the digital computer, which makes it possible to increase the accuracy of the output of the output and simplify the operation of such measurement equipment.

Claims (3)

1. Japanese Patent No. 26764, cl. 102E214.3, publ. 1973. 2. The patent of the USA 3769464, cl. 179-100.2, publ. 1973. 3. Author's certificate К ° 291243, М. Кl.2 G ИВ 27/10, 1969 (prototype).