SU371606A1 - LIBRARY ^ :: cl - Google Patents

Description

one

The invention relates to the field of information processing and is intended for use in storage devices of computing machines on magnetic tapes, disks and drums.

A device is known that contains a “NOT-AND (mismatch)” circuit, the output of which is connected through a waiting multivibrator IK to its input, two triggers connected via another waiting multivibrator, and a null-organ connected through a delay line and the “And” counting input of the third trigger

The purpose of the invention is to simplify the device.

This is achieved by the fact that the output of the circuit "NOT-AND is connected directly to another circuit" AND connected to the output of the third of the flip-flops, and through an additional delay line and the circuit "OR to the input of the zero setting of this trigger.

FIG. 1 is a block diagram of a device for reproducing a phase-modulated signal from a magnetic recording medium; in fig. 2 - timing diagram of the scheme.

The device performs two functions: signal detection and recovery of a code recorded on a magnetic tape, drum, or deok.

A magnetic recording amplifier at the input / device receives a phase-modulated signal of the carrier frequency sho (Fig. 2a). Signal detection occurs as follows. When the input signal exceeds the positive level applied to the threshold element 2, the trigger 3 is set to one (Fig. 2.6) and the enabling potential is applied to the gate 4. From the voltage drop at the output of the trigger 3 by means of the differentiating unit 5, start impulse of the waiting multivibrator 6.

The pulses from the zero-organ output 7 (Fig. 2.8) through the valve 4 and the delay line 8 arrive at the counting input of the trigger 9 (Fig. 2, d) and the mismatch circuit 10.

With the help of the waiting multivibrator 6, the first two pulses from the output of the zero-organ to the mismatch circuit are not transmitted (Fig. 2e, f). The impulse produced when the input signal exceeds the negative level set on the threshold element 11 sets the trigger 12 to the unit state (Fig. 2, g) through the valve 13 in the presence of the resolving potential from the next multivibrator 6 (Fig. 2 d) . At the same time, the pulse generated by the differentiating unit 14 from the falling edge of the pulse from the output of the waiting multivibrator 6 does not pass through the valve 15, which confirms the fact of detection of the signal. The third in order impulse, corresponding to zero signal transition, passes through the mismatch scheme and starts the multivibrator 16, the output pulse of which is chosen equal to D of the carrier frequency period 0) 0 (Fig. 2, g). Due to this, regardless of the code, the sync pulses from the output of WINE 17 are removed one by one pulse per period (Fig. 2, g). The clock pulses through delay line 18 and the OR 19 scheme (Fig. 2, s) set trigger 9 to the zero state (Fig. 2, / s). As a result, a sequential output code (Fig. 2, L) is formed from the clock pulley 20 of the code pulse 1pulses after the valve 21. Thus, the output code is formed as a result of the demand of the states of the trigger 5 at the end of each period of the carrier frequency. After the information has been read out, a reset pulse arriving on bus 22 transfers device B to its original state. Object of the Invention A device for producing a phase-modulated signal from a magnetic recording medium, comprising a NOT-AND circuit whose output is connected via a standby multivibrator to its input, two triggers connected via another standby multivibrator, and a null organ connected via a delay line and a circuit "And with a counting input of the third trigger, characterized in that, in order to simplify the device, the output of the circuit" NOT-AND is connected directly to another circuit "AND connected to the output of the third of the mentioned triggers, and through The main delay line and the “OR — to the input of the Zero setting of this trigger.

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