SU1078458A1 - Device for reproducing magnetic pulse-duration modulated record - Google Patents

Description

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 The invention relates to instrument making, namely, to an apparatus for magnetic recording and reproduction using pulse-width modulation of signals. A device for reproducing a magnetic pulse-width modulated recording is known, which contains a magnetic-induction reproduction head, an amplifier-shaper, a synchronized pulsed oscillator, a trigger, an integrator, a dongle, a memory with a sequential key differentiating chain and two waiting relaxers. In order to reduce the likelihood of information distortion, when a number of pulses fall out during playback, the device contains a synchronized oscillator p. . The disadvantage of this device is a reduction in the accuracy of information reproduction in the event of a precipitation. This is due to the fact that the period of reproducible pulses and the period of natural oscillations of the oscillator are generally different. Closest to the proposed technical entity is a device for playing a magnetic recording, which contains serially connected magnetic playback head, amplifier, trigger, integrator, controllable key, analog storage unit, output terminals; as well as three waiting relaxers and a matching circuit. The device is characterized by a low probability of distortion of the output signals when a pulse is dropped. 2 The disadvantages of the known device are the complexity of its functional scheme and the need for large hardware costs for its manufacture. The purpose of the invention is to simplify the device. The goal is achieved in that a device containing serially connected magnetic playback head, amplifier, trigger, integrator, control key, analog storage unit, output terminals and two waiting relaxers, the first of which is connected to the output of the amplifier, and the output - The inverter is connected to the control input of the integrator, while the output of the second is connected to the second input of the control key, the input of which is connected to the output of the amplifier, and the output to the input of the second waiting relaxator. The drawing shows a block diagram of a device for reproducing a magnetic recording. The main circuit of the device consists of serially connected magnetic playback head 1, amplifier 2, trigger 3, integrator 4, a control key 5, an analog storage unit 6 and output terminals 7. The amplifier's output and control of the integrator's input include a standby relaxator 8, and between the amplifier output and the second input of the control key are connected in series the inverter 9 and the second waiting relaxer 10. The device operates as follows. When passing past the magnetic head 1 of the magnetized section of the magnetic tape, the leading front of this section induces a pointed positive pulse in the magnetic head. The amplified pulse from the output of amplifier 2 is supplied to the trigger 3, the waiting relaxer 8 and through the inverter 9 to the waiting relaxer 10. In this case, the trigger switches to another state, the waiting relaxer 8 is released. a short pulse is injected, and the waiting relaxer 10 remains at rest, since its input is affected by a negative pulse from the output of the inverter 9. During the pulse time at the output of the waiting relaxer 8, the integrator 4 returns to its initial state. After this, the integration process begins, which continues until the passage of the magnetized area by the magnetic head 1 is completed. As the magnetic field of the magnetic tape passes by the head 1, a negative impulse is induced at its output. In this case, the trigger 8 returns to the initial state, the waiting relaxer 10 generates a short pulse, and the relaxer 8 remains at rest. The pulse from the output of the relaxer 10 switches the key 5 to the conduction state for some time. During this time interval, the voltage from the output of the integrator 4 is fed to the input of the analog storage unit b, and from it to the output, clamps. After returning the key 5 to the disconnected state, the voltage at the output of the analog storage unit b remains constant until the next moment the key is closed. The proposed device works steadily with the loss of pulses. Thus, when a positive impulse corresponding to the front of the magnetized area falls out, the waiting relaxer 8 does not generate a pulse returning integrator 4 to the initial state, and the voltage at its output remains unchanged compared to the period when the reproduced pulse was defect free. When playing the next faultless negative pulse corresponding to the decay of the magnetized area, the relaxer 10 generates a pulse, switches the key 5 to the conduction state, resulting in the voltage from the output of the integrator 4 being transmitted to the analog storage unit 6. produces a pulse and the voltage at the output of the storage unit 6 does not change compared with the previous period. In this way

When any pulse is dropped, the voltage at the output of the analog storage unit does not change from the output voltage during the previous period, when the reproducible pulses were defect-free.

The introduction of the inverter into the proposed device for reproduction and the elimination of two block-schemes of comparison and the third waiting relaxer distinguishes the device from the indicated prototype. The proposed device is simpler, which saves components when it is manufactured.

Claims (1)

DEVICE FOR PLAYING A MAGNETIC AND IROTIC-PULSE A MODULATED RECORDING containing a series-connected magnetic head, amplifier, trigger, integrator, controlled key, analog storage unit, output terminals, as well as two waiting relaxers, the first of which is connected to the amplifier output by the input and by the integrator to the control input, the output being the second is connected to the second input of the controlled key, which differs in that, in order to simplify it, it is equipped with an inverter, the input of which is connected to the output of the amplifier, and the output is connected to the input>> * of the second waiting relaxer. _with oo. Joint venture