SU731460A1 - Device for reproducing digital information from magnetic carrier - Google Patents

Description

FIG. 1 shows a diagram of the device; in fig. 2 - time diagrams of the device operation are given.

A device for reproducing digital information from a magnetic carrier contains an inertial generator /, a counting trigger 2, an equalizer 3 of the temporal distortions of the pulses formed by the vasproduced amplifier (not shown), a separator 4 of the pulses IH delay element 5.

Corrector 3 temporal distortion includes) -triggers 6, 7, 8 n scheme OR 9. D-triggers b and 7, the inverse outputs of which are connected to the inputs of the scheme OR 9, represent two identical correction channels. 1) The trigger 8 is the driver of the pulse duration of the corrected pulse sequence of the playback signal.

The device works as follows.

The pulses of the reproduced two-frequency signal 10 (Figs. 1 and 2), formed by the reproduction amplifier, are fed to the inertial generator / and four. cut delay element 5 - corrector 3 time distortion. The generator J operates at a multiple frequency of the reproduced two-frequency signal and generates sync pulses // in phase with the leading edge of the pulses of the undistorted reproduction signal. The repetition period of the clock pulses is equal to the period T of the coding clock frequency, and the duration of the generator pulses is 0.5 G. A trigger 2 with a counting input, triggered from the falling edges of the clock pulses, produces waiting times for information N1, N2, N3 (signals 12 and 13, Fig. 2). The duration of the sleep intervals is equal to T. The pulses of the reproduction signal, which do not have temporal distortions, are set in the middle of the sleep intervals with the help of delay element 5.

During the interval N1 of waiting for information, the high potential at the direct output of the counting trigger 2, which is connected to the 1) -input) -trigger 6, allows recording of the playback signal pulse K.1 through the synchronization input of this trigger 10. From flip-flop 6 (signal 14), the zero input of this flip-flop is made by a high potential at the inverse output of flip-flop 2 (pulse N2 of signal 13). Similarly, the K2 pulse is recorded and read into the D thrigger 7, which, due to temporal distortions from the middle of the information waiting interval -N2, is shifted by the value of Tr (signal K2 of the signal 15).

Thus, when the leading edges of the pulses of signals 14 and J5 are associated with the leading edges of the pulses of the reproduction signal W, whose location

in the current waiting interval, the information depends on the value of the back edge is rigidly attached to the beginning of the next information wait interval, i.e., to the leading edges of the pulses of signals J2 and 13, which are generated by trigger 2 from the sync pulse U /.

Further, the signals 14 and 15 collected by the OR 9 circuit, in the form of a signal 16 are fed

to the sync input of the O-flip-flop 8, which is triggered by the back, temporal-free fronts of the pulses of this signal, and is damped by the leading fronts of the pulses of the signal 11. As a result, the output of the trigger 8 produces a corrected pulse of the playback signal 17 with a fixed pulse duration approximately equal to 0.57. This simplifies the pulse separator circuit 4, which becomes elementary in the presence of a continuous sync signal (signals 18 and 19).

Claims (2)

1. US Patent No. 3641525, cl. 340-174.1, publ. 1972. 2. US Patent No. 3831194, cl. 360-45, published. 1974 (prototype). L 75