SU886192A1 - Digital signal generator - Google Patents

Description

(54) DIGITAL SIGNAL GENERATOR

The invention relates to radio engineering and can be used to create signals of various shapes. A digital sine generator is known, in which a pulse generator is connected through a distributor along several branches, comprising a reversible counter, a decoder, a digital-to-analog converter (DAC) with the inputs of an adder, the output of which is loaded on filter I). However, this generator produces a signal of only one form - a sinusoidal one. A digital signal generator is known, comprising a series-connected generator and a frequency divider, sequentially; tally connected reversible counter and power supply unit, serially connected digital-to-analog converter and amplifier, and the first encoder | 2). However, the known device produces a signal of only one form. The purpose of the invention is to expand the functionality by increasing the number of forms of the generated signals. The goal is achieved by the fact that a digital signal generator containing a series-connected generator and a frequency divider, a series-connected reversible counter and a memory block, a series-connected digital-analog converter and an amplifier, and the first encoder, between the output of the first encoder and the control input of the frequency divider are entered the first multiplexer, between the output of the power divider and the counting inputs forward and backward of the reversing counter, is the second multiplexer, the control inputs of which are dinenets with control inputs of the first multiplexer, serially connected OR-NOT elements and a logic unit, the second input of which is connected to another output of the reversing counter, are entered between the output of the second multiplexer and the third and fourth inputs of the logic unit between the output of the reversible counter the first and second counts are entered respectively; There is an input element between the output of the second counter and the connection point of the zero inputs of the first, second and reversible counters, the other input of which is connected to the starting input of the digital signal generator, between the output of the reversing counter: and the input of the digital-analogue converter — the third multiplexer, the other input of with the output of the memory block, as well as the second encoder, the input of which is connected to the control input of the amplifier, and the third, fourth and fifth encoders, the inputs of which are connected to other inputs mi of the first multiplexer.

FIG. 1 shows the structural scheme of the proposed digital signal generator; in fig. 2 - diagrams for the generator operation.

The digital signal generator contains: first, second, third, fourth, fifth encoders 1, 2, 3, 4 and 5, first, second, third multiplexers 6, 7 and 8, generator 9, frequency divider 10, reversing counter And, first , second counters 12 and 13, digital-to-analog converter 14, amplifier 15, memory -16, element OR NOT 17, element AND 18, logic unit. nineteen.

The device works as follows.

When applying a logical "1 to the input of the element And 18 signal passes this circuit and sets in" About the counters 11, 12 and 13. This triggers block 19, connecting through multiplexers 6 and 7 the first encoder To the input dividers 10, and the output divider to the input bills forward counter And, which starts counting pulses, the period of which is proportional to the number set on the first encoder 1. As a result, the signal at the output of counter 11 increases linearly to the maximum value for the time typed on the encoder 1 (Fig. 2d) Tfronta ) With the appearance of a logical oh - "1 at the output of the higher bit of counter 11, logic block 19 is activated and connected via multiplexers 6 and 7 and divider 10 to the encoder 3 to the input of counter 12. Counting pulses to the input of counter I cease to arrive and its output information forms a vertex 2i, Tversh -) - This state lasts until logical 1 1 is reached at the output of counter 12, while block 19 is activated and connects the encoder 4 through divider 10 to the counting input back of counter I. Information on the output of this counter falls according to the linear law to “zero for time,“ and on the encoder 3. When reaching "Zero, element 17 is triggered, which leads to triggering of block 19. In this case, the encoder 5 is connected through divider 10 to the input of counter 13. Counter 11 stops, information on its output remains, but time the operation of the counter 13 is zero. After appearance at the exit

the higher bit of the counter 13 is logical “block 19 is triggered and multiplexers 6 and 7 close the flow of pulses and the inputs of counters 11, 12 and 13. When applying

and the start-up input of the generator of the new impulse, the generator is restarted. In the multiple pulse mode, the logical input is always fed to the start input. In this case, the appearance of the logical “1 at the output of the most significant bit of the counter 13

0 will be similar to the start of the generator, creating impulses, the duration of which is paused by the encoder 5 (Fig. 2n).

The output information from the output of counter 11 is fed through multiplexer 8 to the output of the instrument and to the input of the DAC 14, which converts the digital signal to analog. The analog signal is amplified in amplifier 15, the transmission coefficient of which is determined by encoder 2, and fed to

generator analog output. In this case, the output pulses have fronts and cuts, which vary linearly. Information from the output of the counter 11 is also supplied to the address inputs of the memory of the coping device 16 (RAM) into which, for example, the shape of the first quarter of the sine can be recorded. If the multiplexer 8 is switched to the mode when it connects the output 16 and the input of the DAC 14, then the generator output signals will have fronts and cuts, varying according to the sine law. If the pause time is zero, then the generator output signal has a half sine wave (Fig. 2,

Thus, the proposed generator

It has the ability to create a pulse, the edges of which you can take the form of a straight line or curves recorded in the memory. The lengths of the fronts, the cutoff of the top and the pauses between the impulses amn are recruited by the encoders. The number of forms of a single pulse is therefore large. The main, pronounced forms can be twelve. As many species can create basic forms of multiple signals.

Claims (2)

1. USSR author's certificate number 666628, cl. H, 03 B 19/00, 1978. 2. US Patent No. 3657657, cl. 328-14. 1972 (prototype). BbiK.tJi fig.T rJ S s