SU832746A1 - Device for automatic switching of registering apparatus in communication lines with frequency modulation - Google Patents

Description

The invention relates to automation and telemechanics and can be used in FM receivers of communication channels.

A device is known for automatically turning on recording equipment in frequency-modulated communication lines, comprising a unit for extracting and generating an input signal, the output of which is connected via a key to the input of the first threshold unit, the output of the current source and one output of the capacitor, the other output of which is grounded, and also an integrator, the output of which is connected to the input of the second threshold block, and the shutdown block ^{15 of the} equipment flj ·

However, the known device has low noise immunity.

The purpose of the invention is to increase noise immunity.

This goal is achieved by the fact that in the device for automatically turning on the recording equipment in communication lines with frequency modulation, containing a block for extracting and generating an input signal, the output of which is connected via a key to the input of the first threshold block, the output of the current source and one output of the capacitor, the other terminal of which is grounded and also an integrator, the output of which is connected to the input of the second threshold block, and the unit for turning off the equipment, a third threshold block, a trigger, and two AND elements are introduced, the outputs of which connected to the inputs of an integrator, the output of which is connected to the input of the third threshold block, the output of which is connected to the first inputs of one AND element and the trigger, the second input, which is connected to the output of the second threshold block and the first input of the other AND element, to the second input of which the first the trigger output, the second output of which is connected to the second input of one AND element and the input of the equipment shutdown unit, and the output of the first threshold block is connected to the corresponding input of the integrator.

1 shows a block diagram of the electrical device to automatically turn registri- ⁵ ruyuschey apparatus; figure 2 - timing diagrams of the operation of the device.

The device comprises a unit 1 for extracting and generating an input signal of ₁₀ la, a key 2, a current source 3, a capacitor 4, a first threshold unit 5, an integrator 6, a second and third threshold units 7 and 8, a trigger 9, elements 10 and 11, and a unit 12 turning off the equipment.

The device operates as follows.

From the output of block 1 selection'and the formation of the input signal through the key ₂ θ '2 to the input of the first threshold block 5 receives pulses (figure 2, diagram O). In this case, the capacitor 4 in the pause between turning on the key 2 tends to charge to the trigger level ₂ 5 of the first threshold block 5 (Fig. 2, Diagram. (Y). During a continuous working signal, the capacitor 4 does not have time to charge to the trigger level of the first threshold block 5, θ ₃ at whose output is present at this + "(figure 2, graph c). in the presence of working, signal interference, leading to a transient its disappearance, the capacitor 4 ditsya ₃₅ manages charge-up level of the first switching unit 5, the threshold that causes appearance on his Exit zero potential. Thus, the output of the first threshold block ₄₀ 5 the presence exist short negative pulses corresponding to the presence of interference in the operating signal. Figure 2 (Figure 2) expresses a sequence of pulses at the output ₄₅ of the first threshold Vågå unit 5 in more large scale time.

Under the influence of a positive potential to the input of the integrator 6, during the duration of the useful signal ₅ θ HA voltage was at its output decreases linearly (Figure 2, diagram e). During the action of negative pulses that correspond to signal loss during the action of interference, the process linear _55-frequency voltage drop in a short time becomes linear increase. This continues until the linearly incident voltage reaches the trigger level of the third threshold block 8 U _By p 1. This can happen if the duration of the interference is less than the intervals between them. When the output voltage of the integrator 6 level and _pore 1, the third threshold block 8 is triggered (figure 2, diagram &) and switches the trigger 9 to state 1 (figure 2, diagram · ^). After that, the output of the third threshold block 8 through the And 11 element is connected to the additional input of the integrator 6, closing the servo feedback, which supports the output voltage of the integrator 6 near the response level of the third threshold block 8, which is necessary to prevent the integrator 6. from entering the saturation mode. In addition, when the trigger 9 is set to state 1, the recording equipment is turned on via the equipment shutdown unit 12 (not shown in the drawing).

When a signal is received to turn off the recording equipment (the voltage at the input of the integrator 6 is negative), the voltage at the output of the integrator 6 increases linearly (Fig. 2, diagram e). During the operation of the interference voltage at the output of the first threshold block 5 has the form of short positive pulses (figure 2, diagram 2). During these pulses, the output voltage of the integrator 6 drops linearly. This will continue until the ramp voltage reaches the level U _by p 2. This triggers the second threshold block 7 (Fig. 2, diagram G) and switches trigger 9 to state 0 (Fig. 2, diagram ) After that, the output of the second threshold block 7 through the element And 10 is connected to the second additional input of the integrator 6, closing the servo feedback, which maintains the output voltage of the integrator 6 near the level of the operation of the second threshold block 7. In addition, with the setting of trigger 9 to state 0 through unit 12 turning off the equipment turns off the recording equipment. Further occurrence of short-term interference at the input of the device does not cause the inclusion of recording equipment, provided that the duration of the interference is less than the interval between them.

The introduction of additional elements — an integrator, two threshold blocks, a trigger, two And elements — into the device for automatically turning on recording equipment in the communication lines with the FM allows eliminating the possibility of turning off the recording equipment when short-term interference appears in the working signal and turning on the recording equipment if there is short-term interference in no input signal, it increases the noise immunity and reliability of the device ^-.

The device can be used when transmitting analog signals over conversational communication channels and in many other cases when the duration of the interference is much lower than the duration of the transmission cycle.

Claims (2)

moreover, the output of the first threshold unit is connected to the corresponding input of the integrator. Figure 1 shows the structural electrical circuit of the device for automatically turning on the recording equipment; 2 shows time diagrams of the device operation. The device contains a block 1 for extracting and shaping the input signal, a key 2, a current source 3, a capacitor 4, a first threshold block 5, an integrator 6, a second and third threshold blocks 7 and 8, a trigger 9, elements 10 and 11, and block 12 Turn off the hardware. The device works as follows. . . From the output of the extraction unit 1 and the formation of the input signal through the switch 2, pulses arrive at the input of the first threshold unit 5 (Fig. 2, diagram d). In this case, the capacitor 4 in the pause between turning on the key 2 tends to be charged to the level of operation of the first threshold unit 5 (Fig. 2, diagram d). During the continuous operating signal, the capacitor 4 does not have time to charge to the response level of the first threshold unit 5, the output of which at the same time contains + (figure 2, diagram 8). When there is interference in the work signal, leading to its short-term disappearance, the capacitor 4 is charged to the first threshold unit 5, which causes the appearance of a zero potential at its output. Thus, at the output of the first threshold unit 5 there are short-term negative pulses corresponding to the presence of interference in the working signal. Chart g, (figure 2) expresses a sequence of pulses at the output of the first threshold unit 5 on a larger, time scale. When a positive potential is applied to the input of integrator 6, the voltage at the output of the useful signal is linear (Fig. 2, diagram e). During the action of negative pulses, which corresponds to the loss of the signal during interference, the linear falling process tension for a short. time goes into a linear increase. This continues as long as the linearly falling voltage does not reach the trigger level of the third threshold unit, 8 U1. This can occur if the interference time is shorter than the intervals between them. When the output voltage of the integrator 6 reaches level 1, the third threshold unit 8 is triggered (FIG. 2, diagram &) and switches the trigger 9 to state 1 (FIG. 2, diagram). After that, the output of the third threshold unit 8 through the element I 1I is connected to the auxiliary input of the integrator 6, closure of the following feedback, which maintains the output voltage of the integrator 6 near the trigger level of the third threshold unit 8, which is necessary to prevent the integrator 6. from entering the mode on the spot. In addition, when trigger 9 is set to state 1, recording equipment is turned on through apparatus shutdown unit 12 (not shown). When a signal is received to turn off the recording equipment (the voltage at the input of the integrator 6 is negative), the voltage at the output of the integrator 6 rises linearly (figure 2, diagram E). During interference, the voltage at the output of the first threshold unit 5 has the form of short positive pulses (Fig. 2, diagrams). During these pulses, the output voltage of the integrator 6 decreases linearly. This will continue until the linearly increasing voltage reaches the level and Qo 2. In this case, the second threshold unit 7 (Fig. 2, diagram vt.) Is triggered and switches the trigger 9 to the state O (Fig. 2, diagram A). After that, the output of the second threshold unit 7 through the element 10 is connected to the second auxiliary input of the integrator 6, the closure of the following feedback, which maintains the output voltage of the integrator 6 near the trigger level of the second threshold 7. In addition, with the installation of the trigger 9 into the state. About through the apparatus shutdown unit 12, the recording apparatus is switched off. . The subsequent occurrence of short-term interference at the device input does not cause the inclusion of recording equipment, provided that the duration of the interference is shorter than the interval between them. The introduction of additional elements into the device for automatically turning on the recording equipment in the FM communication lines — an integrator, two threshold blocks, a trigger, two I elements — makes it possible to exclude the possibility of switching off the recording equipment when short-term noise appears in the working signal and turning on the recording equipment in the presence of short-term interference in the absence of an input signal, this increases the noise immunity and reliability of the device. The device may be used in the transmission of analog signals over conversational communication channels and in many other cases where the duration of the interference is much lower than the duration of the transmission cycle. The invention is an apparatus for automatically switching on recording equipment in frequency modulated communication lines, comprising a unit for generating and inputting an input signal, which via a switch is connected to the input of the first threshold unit, the output of the current source and one output of a capacitor, the other output of which is grounded , as well as the integrator, the output of which is connected to the input of the second threshold unit, and the equipment shutdown unit, which is different in that, in order to increase the noNfexo3acuiiueHi, the third threshold block has been introduced , A trigger and two AND gates whose outputs are connected to inputs kogtoryh integrator whose output is connected to the input. The third threshold block, the output of which is connected to the first inputs of one element And and the trigger, the second input of which is connected to the output of the second threshold block and the first input of another element And, to the second input of which the first output of the trigger is connected, the second output of which is connected to the second input single-element And and the input of the unit off the equipment, | And the output of the first threshold unit is connected to the corresponding input of the integrator. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 545090; cl. H 04 L 13/18, 1975. . .-- i 9 3 Um9t