SU737849A1 - Signal level indication device - Google Patents

Description

(54) - DEVICE FOR SIGNAL LEVEL INDICATION

The invention relates to instrument engineering, in particular, to a recording and sound reproduction technique, and is used in recording, reproducing and transmitting electrical signal channels. Devices for signal level indication are known, comprising an indicator with N indicating light emitting elements, N comparators and N keys; one of the inputs of each comparator is connected to the source of the indicated voltage, the other input is connected to the resistive divider of the reference voltage, the control input of the corresponding key is connected to the output of each comparator, each key together with the indicating element forms a series circuit connected to the power source. The displayed voltage is compared with the reference voltage at the inputs of the comparators. When these voltages coincide, the corresponding key opens, providing a luminescence of the indicating element connected to it, and the higher the level of the indicated voltage, the greater the number of luminous INITIATING elements {2, The disadvantage of this device is that device capabilities need to increase the number of indicative elements. This leads to a significant complication of the device, since a key and a comparator, a relatively complex analog device, are required to control each indicator element. Moreover, an increase in the number of channels in which it is necessary to indicate levels up to two (for stereo systems) or up to four (for quadraphonic) leads to an increase in the volume of electronics, respectively, two and four times. The disadvantage of this device is also the impossibility of simultaneous indication of average and peak levels. Such a possibility has a fundamentally important 31st value when displaying / even a signal in the sound transmission channel, since the indication of the average level allows you to judge the volume of the sound program, and the indication of the peak level allows you to prevent overloading the sound transmission channel, in particular the recording media, and thereby eliminate this distortion of the sound program.

The closest technical solution to the present invention is a level indication device comprising an M-position indicator, made on LEDs that are connected via the key to the first power supply terminal through one key and to the second power source terminal through the corresponding decoder outputs . The inputs of the descrambler are connected to the corresponding outputs of the counter, whose input is connected to the output of the pulse generator, Controls key input is connected to the output of the comparator, one of the inputs of which is connected to the source of the reference voltage, and the other to the source of the indicated voltage. An exponential pulse generator is used as the reference source, the generator being controlled by the counter in such a way that the pulse duration is equal to the time of one counting cycle 2,

This device has a more simplified structure compared to the described one: with an increase in the number of channels, for example up to two, the electronic circuitry of the circuit, including one comparator and key, doubles. In addition, this device is built, in general, on digital circuits that are easily integrated into a solid-state chip.

The main disadvantage of this device is the impossibility of simultaneous indication of average and peak levels.

The invention of the invention is the expansion of the Diff eeROTo range of the audio channel by simultaneously indicating the average and peak levels of the indicated one. signal. ;,

This goal is achieved by the fact that the device for indicating the signal level, containing a threshold element connected by one input to the output of the reference voltage source, and a series-connected generator, counter, decoder and multi-position indicator, the radiating elements of which on the other hand are interconnected and through the Key, they are connected to the power bus, a switch, a differentiator, a trigger and detectors of the middle and peak levels are entered, which are connected to the input of the device, and the outputs via the switch or - with another input of the threshold element connected by the output through the differentiator to the first input trigger a, the second input of which is connected to the generator's output, and output from the pack: in the key input, and controlling the inputs of the switch are connected to the counter from the counter and the outputs of the decoder are connected to the inputs of the source of a high voltage, one of the free inputs of which is connected to the Power bus.

FIG. 1 is a block diagram of a level indication device; in fig. 2 shows voltage diagrams at the outputs of 5 blocks during the operation of the proposed device.

The level indicator device contains a ten-type indicator 1. The first eight indicators of their elements

The Q indicator 1 is used to indicate a mid level not exceeding the nominal, the next two indicating elements are used to indicate peak levels exceeding the nominal one. The identifying elements are connected by one pin through the key 2 to the first terminal of the power supply 3, and the other pin through the corresponding outputs of the decoder 4 are connected to the corresponding outputs of the binary-ten counter

 5, operating in code 8-4-2-1. To the input of the counter 5 is connected to the output of the generator b pulses. The counter 5 together with the decoder 4 forms a distributor, to the input of which the output of the generator 6 continuously receives pulses of frequency F. Each of the ten indicator elements of the indicator 1 is alternately connected to the power source 3 through the corresponding output of the decoder 4 with the frequency

F Oh, IF.

This frequency should not be lower than the frequency "at which the luminescence of the corresponding indicating element, due to the inertia of the vision, is observed to be continuous. On this basis, the frequency of the pulses generated by the generator 6 is chosen from the condition

 SOUTH

The control input of the key 2 is connected to the output of the trigger 7, one of the inputs of which is connected to the output of the generator 6 pulses, and the other to the output of the differentiator 8, which is connected. connected to the output of the comparator 9; The first input of the comparator 9 is connected to the source 10 of the reference voltage, and

0 a second input through the first key of the two-channel switch 11 is connected with the output of the detector 12 of average value, and through the second key with the output of the peak detector 13. The inputs of the detectors

5 12 and 13 are connected to the input 14 of the device as a whole.

Each pulse coming from the pulse generator 6 to one of the inputs of the trigger 7 transfers it to the initial state, in which the key 2 is closed and the indicating elements are not illuminated. To unlock the key 2 and illuminate the corresponding indicating element, another impulse 7 must receive a pulse generated

5 by the differentiator 8 from the voltage drop arising at the output of the co-op 9 if the indicated voltage at its input coincides with the reference voltage. Thus, the voltage on the illuminated indicating element supplies with for the length of time between the pulse arriving at trigger 7 from the differentiator 8 and the next followed by a pulse coming from the generator output of 6 pulses. Therefore, the duration of the impulses generated by the generator should be much less than the period they follow and, in the case of the start of the counter 5 from the leading edge of the pulses, should not exceed the duration of the pulses formed by the differentiator 8. The code bit is connected to the control input of the first key of the two-channel switch 11 and the input of the inverter 15, the output of which is connected to the control input of the second key. Before the ninth pulse arrives at the input of the counter 5, its state at the high-order output corresponds to zero. In this case, the first key of the two-channel switch 11 must be open, and the second is closed. After the arrival of the ninth input pulse, the state of the counter 5 at the output of the most significant bit changes to one, with the result that the first key closes with and the second opens. Thus, during the single cycle of the decimal counting, the outputs of the detectors 12 and 13 are alternately connected to the second input of the comparator 9. In this case, the first eight steps of the reference voltage compare the average level and the subsequent two - the peak level. The reference voltage source 10 is made on dividers with a common circuit of parallel connected resistors and a capacitor, in one arm and ten resistors in the other. Each of the ten resistors is connected through the corresponding output of the decoder 4 to the second terminal of the power supply 3, and the circuit in parallel, the connected resistor and capacitor is connected to the first 1 meter terminal. The resistance of each of the ten resistors is chosen so that to the power source, the voltage on the divider output increased step by step in accordance with the level values on the indicator scale 1. A capacitor connected in parallel with the resistor between the common point of the divider and the first terminal power supply 3, tightens the voltage rise time at the output of the divider, and this time should exceed the switching time of the keys of the two-channel switch 11 In addition, a differentiator 16 is connected to the second input of the comparator 9, the input of which is connected to the second helix 4 via the zero output of the decoder 3 power source. Due to such an inclusion, when a first pulse arrives at the input of the counter 5, a short pulse formed from the voltage drop is applied to the second input of the comparator 9; at the zero output of the decoder 4. The amplitude of this pulse must exceed the level of the first step of the reference voltage at the first input of the comparator 9, so that the device will return to the initial position for the duration of this impulse kb. The device works as follows. The pulses generated by generator b (Fig. 2, a) are sent to one of the inputs of the trigger 7 and the input of the counter 5. The trigger 7 is reset to which the key 2 is closed. The pulses arriving at the input of the counter 5,. Lead to a change in the state at its outputs and, accordingly, to an alternate change of state at the corresponding outputs of the decoder 4. The first input pulse of each regular decade leads to a change in the state at the zero output of the decoder 4, the second impulse causes a change in state at the first output, etc. In FIG. 2c, d, d are the voltage plots on the zero, first and ninth outputs of the decoder 4. Through each output of the decoder 4, when the status changes on it, the second terminal of the power source 3 alternately connects one of the conclusions of the corresponding indicator 1 of the indicator 1 Simultaneously with the output of the indicating element, the corresponding resistor of the source 10 of the reference voltage and its output to the first input of the comparator 9 is connected to the second terminal of the power supply 3, during each cycle of the ten bills fed stepwise increasing voltage. In the absence of the indicated signal1 at the input 14 of the device, only short impulses generated by the differential 16 from each successive voltage drop at the zero output of the deshifter are received at the second input of the comparator 9 (Fig. 2e). Under the influence of each of these pulses, the comparator 9 is set to its original position, and then, when the falling edge of the pulse declines to the level of the first step of the reference voltage, the comparator 9 is activated and a voltage drop occurs at its output. Differentiator 8 forms a pulse from this differential, which is applied to one of the inputs of trigger 7 immediately after the first pulse coming from the generator output.

737849

6 to the other input of the trigger 7 and puts it into a state in which the key 2 opens, providing the first indicator element 1 to light up. The second pulse, coming from the output of the generator 6 to the other input of the trigger 7, returns it to its initial state at which jpoM the key 2 is closed and other indicative elements are not illuminated.

When a displayed signal appears at the device input 14, the voltage corresponding to the average signal level is formed at the output of the detector 12, and the voltage corresponding to the peak level of the signal at the output of the detector 13. Both voltages are conventionally represented by horizontal lines combined for consistency with the plot of this voltage (Fig. 2, g). Since the outputs of the detectors 12 and 13 are connected to the second input of the comparator 9 via a two-channel switch 11, which is controlled by output

of the older bit of counter 5, then, as mentioned above, the detector of average level 12 is connected

To the second input, KOMnapaTotia 9 is in the first eight cycles of each decade of the tenth count, and the peak detector 13 - for the next two. - .- .. ,, „,,„. ,, ....

In this example (Fig 2rk), the voltage corresponding to the average signal level coincides with the sixth step of the reference voltage, which results in a comparator output. 9, at the time of coincidence, a voltage drop occurs (Fig. 2.3). Differentiator 8 generates a short pulse from the voltage drop (Fig. 2i), which, with a delay after the sixth pulse of the generator 6, arrives at the corresponding input of the trigger 7. The trigger 7 is then set to the position at which the key 2 opens, providing exposure to

the sixth indicating element of the indicator 1 (Fig. 2).

The seventh pulse, coming from the output of the generator 6 to the other input of the trigger 7, returns it to its original state, in which the key 2 closes and the supply of voltage to the indication of the SCH elements ceases.

When the ninth pulse from the output of the generator b to the input of the counter 5 is activated, the state of the highest bit changes to the opposite one (Fig. 2.6), providing the inverter 15 and two-channel switch 11 to disable the average level detector 12 d Terminal 9 and connection to the peak detector detector 13. At this, koMpar & 9 returns to the initial state, and then, with increasing

eight

the reference voltage and its coincidence (in this case, its ninth stage) with the voltage corresponding to the peak level, the comparator 9 again changes its state to the opposite (Fig. 20). In this case, a voltage drop occurs at its input. Differentiator 8 generates a pulse from this differential, following the ninth pulse of generator b and arriving at the corresponding input of trigger 7, putting it into the state where key 2 is opened, illuminating the indicator indicator element 1 (Fig.). The tenth pulse, coming from the output of the generator b to the other input of the trigger 7, returns it to the initial state, in which the key 2 closes and the supply of voltage to the indicating elements ceases. When the eleventh pulse arrives at the input of the counter 5, the comparator 9 returns to its initial state.

Thus, with repeated repetition of cycles of decimal counting on the indicator, two indicator elements simultaneously light up, and a change in the levels of both medium and peak results in one indicator elements being extinguished and others being illuminated, which in dynamics is perceived as moving luminous hares along the scale. indicator 1 depending on the level of the displayed signal.

Thus, the simultaneous indication of the average and peak signal levels in this device makes it possible not only to get rid of a special overload indicator, but also to establish a more optimal mode in the process of sound transmission.

Claims (2)

1. The patent of Great Britain 1342859. cl. G IV, 1974. 2. Radio Fernschen Eeekroniklll 976, 17. p. 573-575. 737849