SU873389A1 - Synthesizer of periodic functions with limited spectrum - Google Patents

Description

(54) PERIODIC FUNCTIONS WITH RESTRICTED SYNTHESIZER The invention relates to radio engineering and can be used in radio technical installations for various purposes, in particular, in communications equipment in automatic tuning systems for frequency characteristics correctors, as well as in industrial communications and electronic industry. A known synthesizer of periodic functions with a limited spectrum, containing a series-connected crystal oscillator and a clocked shift register, as well as a shaping adder, a comparison device, a unit of reference voltages, and integrating elements fl. However, the known synthesizer has a low accuracy in shaping the output signal. The purpose of the invention is to improve the accuracy of the formation of the output signal. To do this, in a synthesizer of periodic functions with a limited spectrum, containing sequentially connected quartz oscillator and a clocked shift register, as well as a forming adder, comparing device, a unit of reference voltages

SPECTRUM and integrating elements between the outputs of a clocked shift register and the corresponding inputs of a formative adder introduced forming keys, and also entered keys of error signals, adders of error signals, keys of reference voltages, adder of reference voltages, inverting amplifier and series-connected filter, correcting element, device time selection and shift register, the outputs of which through the keys of the error signals are connected to the inputs of the corresponding integrating elements, the outputs of which through the adders of signals, errors are connected to other inputs of the corresponding forming keys, the outputs of the reference voltage block are connected to other inputs of the corresponding error signal adders and to the first inputs of the reference voltage cooTBeTCTBsnonmx, the outputs of which are podk.teny to the inputs of the adder reference voltages, the output which is connected to one of the inputs of the comparison device, whose other input is connected to the output of the correction element, and the output of the comparison device through an inverting amplification It is connected to other inputs of the keys of the error signals, to the other inputs of each of the keys of the reference voltages the corresponding outputs of the shift register are connected, and the input of the filter is connected to the output of the shaping.Summator. On the left, the textbook presents a structural electrical circuit of the proposed synthesizer. The synthesizer of periodic functions with limited spectrum contains a quartz generator 1, a clocked shift register 2, forming keys 3 forming adder 4, filter 5, correction element b, time selection devices 7, comparing device 8, inverting amplifier 9, keys 10 error signals, register shear 11, integrating elements 12, adders 13 error signals, block 14 reference voltages, 15 reference voltages, adder 1 reference voltages. The synthesizer works as follows. Quartz oscillator 1 produces two series of pulses, one with a frequency f. , determines the period of the synthesized function, the friend with the frequencies -l multiple of f, the determined reference values of the functions. Pulses with a frequency f are recorded in the first bit of a clocked register dd 2, representing a discrete delay line, the advance of a pulse along the discharge occurs with a clock frequency. Potentials appearing at the tap of the synchronized shift register open at appropriate points in time the keys 3 The signals of which are added to the forming adder 4, as a result of which a step-like signal is fed to the filter 5. Filter 5 limits the frequency spectrum so that the transition region lies between the frequencies nf and (n + l) f, as a result, with a limited spectrum, it is enough to accurately form the signal to set the value of the function at the sample times. The signal after filter 5 is fed to a correction element b, eliminating frequency distortion; made by fil.trom. The output signal from the output of the corrective element is fed to the time selection device 7 and the comparison device 8. The time selection device makes the frequency f - f and f. f from the output signal. The output of the comparison device through the inverting amplifier 9 is loaded on the inputs of the keys of the error signals 910, which are controlled by the shift register 11, which operates similarly to the described clocked shift register 2. The signals from the keys 10 of the error signals that determine the error of the function in the sampled values are integrated by integrating elements 12 and are applied to the adders 13, where they are added to the reference voltages that determine the values of the functions at the reference points. After the adders, signals are supplied to the inputs of the forcing keys. To isolate an error on a comparison device, one of the inputs of which provides an output signal, signals from a block 14 of reference voltages are taken, which are supplied with keys of 15 reference voltages controlled by the shift register 11 to the adder of the reference voltages and at appropriate points to the second input of the comparing device. In some particular cases, for example, to obtain the function sinuUc (t-Kut), the synthesizer circuit (t} c (t - KAt) is greatly simplified, since there is no need for a block of reference voltages 14, in the keys of the reference voltages 15, in the adders 13 and the adder of the reference voltages 16. In this case, the second input of the comparing device gives zero values to the reference times K At and the value of the output signal is inverted only when Km is a multiple of T. and feeding into the signal conditioning circuit, some Interval adjustment of the synthesized function. The proposed synthesizer of periodic functions with limited spectrum replaces the reference synthesizer used at present, because it provides higher accuracy of signal generation at a fixed circuit complexity, or allows you to drastically simplify the circuit, retaining the specified accuracy of signal generation. Positive effect is to use an astatic tuning system, in which increasing accuracy is reduced to increasing the number of keys, while maintaining constant E inverting amplifier, comparing present device, the time selection unit, and other complex nodes, whereas in the conventional system increase correction accuracy, requires a common complication sharp circuits formula invention Synthesizer periodic functions with a limited range, comprising

a series-connected quartz oscillator and a clocked shift register, as well as a forming adder comparing device, a unit of reference voltages and integrating elements, characterized in that, in order to increase the accuracy of the formation of the output signal between the outputs of the clocked shift register and the corresponding inputs of the forming adder, the odds are inserted ;; drove the keys n ,, fi ОЧ1И6КИ, the error signal adders, the keys of the reference voltages, the adder of the reference voltages, the inverting amplifier and in series The filter, the correction element, the time selection device and the shift register, the outputs of which are connected to the inputs of the corresponding integrating elements via the error signal keys, the outputs of which through the accumulators of the error signals are connected to other inputs of the corresponding generating keys, the outputs of the unit of the reference voltages Yen with other inputs yours Shchi adders signals shit IT

eG al:;: nG °° "- ™ whose reference voltages, outputs

which are connected to cJS aror inputs of reference voltages, the output of which is connected to one of the inputs of the comparison device, at the second OTHER input is connected to the correction element, and the output of the comparison device is connected to the other inputs of the error signal keys to the other inputs from the keys of the reference voltages are connected to the corresponding outputs of the shift register and the input of the filter is connected to the output of the JS; world adder. odds

Sources of information taken into account in the examination

1. US patent No. 4044381 CL.325-320, 08.23.77 (prototype) ..

Claims (1)

A synthesizer of periodic functions with a limited spectrum, containing a series-connected crystal oscillator and a clock shift register, as well as a forming adder, a comparative device, a block of reference voltages and integrating elements, characterized in that, in order to increase the accuracy of the formation of the output signal between the outputs of the clock the shift register and the corresponding inputs of the forming adder, the forming keys are entered, as well as the keys of the error signals, the adders of the error signals, the keys are entered voltages, a reference voltage adder, an inverting amplifier and a series-connected filter, a correcting element, a temporary selection device and a shift register, the outputs of which are connected through the error signal keys to the inputs of the corresponding integrating elements, the outputs of which are connected via error signal adders with other inputs of the corresponding forming keys, the outputs of the reference voltage block are connected to other inputs of the corresponding error signal adders and to the first inputs of corresponding keys of the reference voltages, the outputs of which are connected to the inputs of the adder of the reference voltages, the output of which is connected to one of the inputs of the comparison device, the other input of which is connected to the output of the correction element, and the output of the comparison device through an inverting amplifier is connected to other inputs of the error signal keys, to the other inputs of each of the keys of the reference voltages are connected to the corresponding outputs of the shift register, and the input of the filter is connected to the output of the forming adder.