SU1418685A1 - Digital-analog periodic function generators - Google Patents

Abstract

This invention relates to automatics, computing, and computing. The aim of the invention is to expand the scope by reproducing functions with adjustable cut-off angle. The D / A generator contains 1 pulse generator, frequency dividers 2 and 3 with constant and variable division factors, 4 frequency multiplier, digital dividing device 5, controllable delay line 6, elements 7 and 14, reversible counters 8 and 12, digital-to-analog converter 9 , DC amplifier 10, phase shifter 11, code comparison unit 13, trigger 15, memory register 16, and decoder 17. The generator action principle is based on the formation of a periodic function, comparing its current values with a given code value from the cross sections and the reproduction of the second periodic function with parts of constant amplitude determined by the moments of coincidence of the values of the first function with the cutoff code. 2 Il. (/)

Description

The invention relates to automation and | computer technology and can be used in information and measuring systems of various purposes.

The aim of the invention is to expand the field of application by reproducing functions with an adjustable cutoff,

i FIG. 1 is a block diagram of a digital-to-analog generator of periodic functions; FIG. 2 shows timing diagrams explaining his work,

 The digital-to-analog generator (FIG.) Holds a pulse generator 1, a division 2 parts with a constant division factor, a divider 3 frequencies c; variable division factor, 4 frequency multiplier, digital dividing device 5, controlled delay line 6, first AND 7 element, main reversible counter 8, digital-to-analog converter 9, DC amplifier 10, phase shifter 11 additional reversible counter 12, block 13 comparison of codes, the second element And 14, the trigger 15, the register 16 memory and the decoder 17,

The digital-to-analog generator works as follows.

one:

  In the initial state, the triggers of dividers 2 and 3 frequencies, multipliers 4 frequencies, digital device 5 delays and reversible counters 8 and 12, and trigger 15 are set to zero (the installation circuit is not shown), elements 14 and 7 are open, into register 16 The memory is recorded with a cut-off angle code. With the help of nodes 1-6, a uniform pulse train is formed in a wide frequency range at the output of the controlled delay line 6 (Fig. 2a). Since element 14 is open, they are fed to a reversible counter 8. After converting the output code of counter 8 in converter 9 and amplifying in block 10, a sinusoidal signal begins to form at the output of the device (FIG.). The pulses from the output of the controlled delay line 6 simultaneously enter Additional reversible counter 12, the code from the output of which is fed to block 13 of code comparison. When the codes of the reversible counter 12 and the memory installed in the register, 16 are compared:, at the output of the code comparison unit 13,

An impulse (FIG. 2 6), which, through the element 7, enters the counting input of the trigger 15, switches it, and therefore the element 14 closes. Simultaneously, the same impulse switches the sign trigger of the reversible counter 8 to the subtraction. The formation of a sinusoidal signal is stopped (moment t, fig, 25), since no impulses arrive at the input of the reversible counter 8, and the additional counter 12 continues to count the impulses due to the fact that impulses arrive at its input. Upon reaching the maximum code, counter 12 switches to subtraction, and the code recorded in it begins to decrease as the pulses arrive. When the reversible counter code 12 and the cutoff code recorded in memory register 16 are compared again, another output appears at the output of block 13, a switching trigger 15 that opens And 14, and the sine wave continues (time t, fig. 25) In the future, the operation of the digital-analog generator is repeated. In the case of setting in the memory register 16 a code corresponding to the cut-off angle equal to 0 or -90 °, de-pattern 17 is triggered, which causes the element 7 to close. A sinusoidal chased without truncation (f.ig, 2 &, dotted)

The combination of the generator of the input blocks allows forming a wide range of truncated sinusoidal signals with different cut-off angles. The resolution of setting the cut-off angles depends on the reversible counter and may be 0.1,

Claims (1)

Invention Formula A digital-analog periodic function generator containing a DC output amplifier connected to the output of a digital-to-analog converter connected to the output of a main reversing counter, a pulse generator whose output is connected to the input of the phase shifter, the first input of the frequency multiplier, the counting input of the frequency divider. the division factor and the counting input of a frequency divider with a constant division factor, the output of which is connected to the control input of a frequency divider with variable division connected by the output to the second input of the frequency multiplier and the signal input of the digital division device connected to the control input to the output of the frequency multiplier and to the signal input of the controlled delay line, and output to the control input of the controlled delay line, in order to expand the scope of application by reproducing functions with an adjustable cut-off angle, an additional reversible counter, a code comparison unit, a decoder, a trigger, two And element and the memory register, the output of which is connected to the input of the decoder and the first input of the code comparison unit, connected by the second input to the output of the additional revolving counter, and the output to the first input of the first And element connected by the second input to the output of the decoder, and the output to countable. trigger input and control input reversing the main reversing counter--: a counter, the counting input of which is connected to the output of the second element And connected by the first input to the output of the controlled delay line and the counting input of the additional reversible counter, the second input to the output of the phase shifter, and the third input to the trigger output. 1I