SU591957A1 - Cylindrical magnetic domains readout device - Google Patents

Description

(54) DEVICE FOR READING CYLINDRICAL MAGNETIC DOMAINS

The main galvanomagnetic sensor 9 and the additional galvanomagnetic sensor 10 are located respectively above the main 4 and additional 5 channels and are located at the same distance from the intersection of the channels 8.

Resistors 11 and 12 connected to sensors 9 and 10 in a bridge circuit are outside the film.

1. The operation of the proposed device is based on the well-known method of controlling the movement of a CMD using ferromagnetic applications and a control magnetic field rotating in the plane of a magnetically uniaxial film. The control field induces in the applications magnetic poles A, B, C, D, the interaction of which with the CMD ensures the motion of the latter.

The device works as follows

Perpendicular perpendicular

channel 5 from the source of CMD 6 for each

the period of the governing floor is coming domains

2, which corresponds to the filed information unit.

The main information channel 4 may receive a one or zero, expressed respectively by the presence or absence of domains in the promotion channel.

In the absence of a domain at position C of the main channel 4, the domain at position C of additional channel 5 passes unimpededly to position G at the intersection of 8 channels, and further along positions A, B, C, ... additional kayal passes under the additional sensor 10.

The scattering field of the CMD changes the resistance of the sensor 10. At the output of the bridge circuit, there is a signal "On negative polarity." When a domain (information unit) is present at position B of main channel 4, a current impulse is supplied to annihilator 7, which expands the domain and brings it closer to domain 2 of additional channel 5. At the same time, due to magnetostatic repulsion, domain 2 of additional channel 5 appears in position In the main channel 4, located behind the intersection of the channels. At the next moment, a current pulse is applied to the annihilator 7 and the domain 2, located under the annihilator in the main channel 4, is erased.

Thus, the domains from the additional channel 5 and the main channel 4 do not pass under the additional sensor 10, and the domain 2 of the additional channel falls into the main channel 4 and passes under the main sensor 9. The diffusion field of the CMD changes the resistance of the sensor 9, and at the output of the bridge circuit there is a ' 1 positive polarity signal.

The paths traveled by the CMD from the intersection of channels 8 to sensors 9 and 10 are made equal so that the moments of passage of the CMD under sensor 9, or under sensor 10, coincide with the moment of reading.

The proposed device allows to obtain bipolar signals when reading a unit and zero, i.e., to identify the information signal not only by amplitude, but also by polarity. Moreover, due to the indicated inclusions of the CMD annihilator and the location of an additional galvanomagnetic sensor, the reliability of the device operation increases, since the expanded domains, after interacting with

5 CMD, it is not necessary to go to CMD, for which a certain amount of time is spent, and therefore the interaction of successive domains decreases and the area of stable work increases. In addition, since there is no time spent moving a domain from a bandwidth to

CMD, then the speed of the device for reading the CMD is increased.

Claims (3)

1.W. Strauss "I. Appl. Phus 1971, 42, No. 4, p. 1251. 2.I. Appl. Phus 1971, 42, No. 4, p. 1268. 3. USSR author's certificate No. 526017, cl. G 11 C Il, i4, 197C.