SU871192A2 - Device for reading digital data from magnetic medium - Google Patents

Description

The invention relates to the field of instrumentation, and in particular to the technique of digital magnetic recording on non-specialized media.

A device for reading digital information from a magneto carrier, consisting of a magnetomodulating sensor with pulsed excitation, having a field winding and a signal, one of the outputs of which is connected to the first input of the logic circuit And, a pulse generator, a transistor of a power amplifier supplying the field winding of a magneto-modulation sensor, and a trigger [1].

However, when reading. information provided by the binary code from the effect of electromagnetic interference, false alarms of the device are possible.

The aim of the invention is to increase the noise immunity of the device.

The goal is achieved by the fact that the second device contains the second series-connected signal windings of the magnetomodulation sensor, logic circuit I and a trigger, the single output of which is connected to the third input of the first logic circuit I. The second input of the second logic circuit And is connected to the output of the differentiating circuit, and the third input - with a single output of the first trigger.

In FIG. 1 shows a structural diagram of a device; in FIG. 2 - stress diagrams.

The device comprises a pulse excitation generator 1 connected through a transistor of a power amplifier 2 to a field coil of a magnetomodulation sensor 3, the signal windings of which are connected to the first inputs of logic circuits I 4 and 7, the second inputs of which are connected through a differentiating circuit 5 to the collector of the transistor of the power amplifier 2. Outputs circuits And 4 and 7 are connected to the inputs of triggers 6 and 8, respectively.

The device operates as follows.

In the initial state, the triggers 6 and 8 are set to the same state.

In this case, the third inputs of circuits And 4 and 7 are fed with enabling signals from the individual outputs of triggers 8 and 6, respectively.

Generator 1 generates excitation voltage pulses, which are amplified by * power amplifiers 2 (Fig. 2, diagram a). The shape of the excitation pulses differentiated by the differentiating circuit 5 is shown in FIG. 2, plot b. When reading “1” at the output of the two signal windings of the sensor 3, the signals appear on the VIG diagrams (Fig. 2), where the shape of the first signals, for example, is distorted by the action of a pulsed industrial electromagnetic interference that exceeds the threshold Δ of the device.

; Triggers 6 and 8 are set to their initial position in the same state with the Reset command (Fig. 2, diagram e), which, for example, is supplied synchronously with the excitation pulses. In this case, the third inputs of circuits And 4 and 7 are fed with enable signals from the individual outputs of trigger 8 (Fig. 2, plot and) and the trigger. 6 (Fig. 2, plot h), respectively. When reading “1” at time tt, the output of circuit And 4 (Fig. 2, plot e) shows signals that turn on trigger 6. As a result, · “1” (Fig. 2, plot K) is highlighted on its one output and simultaneously from the other output, the enabling signal does not arrive at the third input of the And 7 circuit until the time b (Fig. 2, plot 3) when the device is again set to its initial position. At the same time * impulse noise having POLO-

A positive polarity at the output of the signal winding and exceeding the response threshold Δ (Fig. 2, diagram d) does not appear at the output of circuit I 7 (Fig. 2, diagram g), which excludes the inclusion of triggers 8 5 (Fig. 2, diagram l )

The present invention improves noise immunity and reliability of reading roystv mouth with non-special magnitonositeley such as steel rails, ropes, tubes, rolled conditions dei ¹⁰ Corollary industrial electromagnetic interference.

Claims (2)

(54) DEVICE FOR READING DIGITAL INFORMATION FROM A MAGNETIC MEDIATOR The invention relates to the field of instrumentation, namely to the technique of digital magnetic recording on non-special media. A device for reading digital information from a magnetic carrier is known, consisting of a magnetically modulated sensor with pulsed excitation, having an excitation winding and a signal one of whose terminals is connected to the first input of the logic circuit I, a pulse generator, a transistor of a power amplifier, supplying the excitation winding of the magnetically modulating sensor , and trigger 1. However, when read. information represented by a binary code, due to electromagnetic interference, false positives of the device are possible. The aim of the invention is to increase the noise immunity of the device. The goal is achieved by introducing into the proposed device the second serially connected signal windings of the magnetic modulation sensor, the logic circuit I and the trigger, the unit output of which is connected to the third input of the first logic circuit I. The second input of the second logic circuit I is connected with the output of the differentiating circuit, and the third input - with a single output of the first trigger. FIG. 1 shows a block diagram of the device; in fig. 2 - diagrams for example. The device contains a pulse excitation generator 1, connected through a transistor of power amplifier 2 to the excitation winding of a magnetically modulated sensor 3, the signal windings of which are connected to the first inputs of logic circuits 4 and 7, the second inputs of which are connected through a differentiating circuit of a power amplifier transistor 2. The outputs of the circuits And 4 and 7 are connected to the inputs of the flip-flops 6 and 8, respectively. The device works as follows. In the initial state, the triggers 6 and 8 are set to the same state. In this case, to the third inputs, circuits 4 and 7, the enabling signals from the single outputs of the flip-flops 8 and 6, respectively, are supplied. Generator 1 generates excitation voltage pulses that are amplified by power amplifiers 2 (Fig. 2a). The form of differentiated differential patterns, chain. 5 excitation pulses are shown in FIG. 2, epyu. B. When reading "1" at the output of the two signal windings of sensor 3, the signals shown in the plots (Fig. 2) appear, where the shape of the first signals, for example, is distorted by the action of a pulsed industrial electromagnetic interference exceeding the response threshold of the device. I Triggers b and 8 are reset to the same position with the command "Reset (Fig. 2, plot e), which, for example, is applied synchronously with the excitation pulses. In this case, on the third i.khods of the circuits I 4 and 7, the enabling signals from the single outputs of the trigger 8 (Fig. 2, plot I) and the trigger are supplied. 6 (FIG. 2, h), respectively. When reading "I" at time ti at the output of the AND 4 circuit (Fig. 2, plot e), signals appear that turn on trigger 6. As a result, "I (Fig. 2, plot c) and at the same time, from another output, there is no allowing signal to the third input of the circuit I 7 until the time point ta (Fig. 2, plot C) when the device is again set to its original position. In this case, impulse interference, having a positive polarity at the output of the signal winding and exceeding the response threshold D (Fig. 2, plot d), does not appear at the output of circuit AND 7 (Fig. 2, plot g), which excludes the inclusion of flip-flops 8 (Fig. 2, plot l). The invention allows to increase the noise immunity and reliability of the device. readings from such non-specific magnetic media, such as steel rails, canals, pipes, rolled products under the conditions of industrial electromagnetic interference. Invention A device for reading digital information from media on aut. St. No. 737985, characterized in that, in order to increase the noise immunity of the device, 1 second is entered after; the signal winding of the magnetic modulation sensor, the logic circuit AND, and the trigger, whose output is connected to the third input of the first logic circuit AND, are inputted into This second input of the second logic circuit, AND is connected to the output of the differentiating circuit, and the third to the single output of the first trigger. Sources of information taken into account in the examination 1. USSR author's certificate JW 737985, cl. G 11 B 5 / 09,13.12.78. // ./ Lj - .ff: f BUT fug, / vsmg % /. / Shch CSpoc d Vsm.4 e % / 7 4, fJed.6tfX.6 cd.6ia.8 a % // -. / r /M.ff-ff