Abstract

It is reviewed an algorithm for defining the difference between the precise and relative amplitude and phase-frequency characteristics of consecutive and parallel oscillating circle. Compаring the measured difference with the preliminary set conditions it is possible to define the quantity of the amplitude, for which is expedient that the precise and relative relations to be used.

1. Subject of assignment – The oscillate circles can find wide application in different sort of radio technical devices. Because of that the analysis of their amplitude-frequency and phase-frequency characteristics in dependence of the elements to be used - L,C,R is a necessary term for taking decisions accordingly to the useage of both group relationships – precise and approximately (it is about the field of “little” amplitude).

“Small” amplitude or “minimal” amplitude of the circle is  Dw (difference between its own frequency wo of fictional oscillate circle and frequency influence ? meaning Dw=Dw_o-w). About designate for amounts of upset, this is the point of its quantity solution. It is logical, that with its increase the different between punctually meaning of analyzed characteristics and its approximate meaning will increase. Consequently, it will be expedient to research different to this end to compare its value with previous applied meaning, which is defines with particular assignment.

2. Defining the amplitude

1. Consecuive oscillating circle

                                                                            ( 1 )

                                                                                      ( 2 )

where ZTinp – precise meaning, Z»inp – relative meaning, Q – specific factor of the circle Dw – absolute setting.

The difference between the precise and the relative meaning is measured by:

                                                                                                 ( 3 )

After replacing (1) and (2), for  comes that

                    ( 4 )

For a phase-frequency characteristics:

                                                                             ( 5 )

                                                                                               ( 6 )

having in mind the upper mentioned relations:

                                                                                           ( 7 )

It is known, that the consecutive and parallel oscillating circles, defined by common elements are referred to the class of the dual two-poles circles. Therefore the following relation is in force:

                                                                                                   ( 8 )

where  – specific oscillation of the circle.

For precise and relative meaning it comes that:

                                                                                                ( 9 )

                                                                                              ( 10 )

The difference between them:

                            ( 11 )

Having in mind (1), (2), and (4) relation (11) can be viewed as a relation of the arguments Q, w and w_o. The phase-frequency characteristics is defined by:

                                                                  ( 12 )

                                                                               ( 13 )

The difference:

                                                                                                                                      ( 14 )
 
 

3. Structural scheme of the algorithm

The algorithm logically is figured on (fig. 1) as a build-up of 12 blocks [3,4]. In block №1 are entered the initial values and quantities, which are in the base of the definition of circle characteristics (a – identification of the circle type; the index ^{“ гр “} carries the high limit values, which are entered for the difference of the precise and relative definitions; is the step for measuring the frequency of the input influence – it is signed with “+” and “-” in dependence of he desired level of modulation of the frequency of the input influence).

Blocks № 2, 4, 7, 8 and 11 are calculative, and № 3, 5, 6, 9 and 10 are for logical comparison. With block 12 are displayed the values of the quantities, which are subject of the analysis.

In blocks №7 and №11 the current value of the frequency of influence is being modulated. Peculiarity of the logarithm is that the calculations of a circle is stopped if one of the conditions is not fulfilled (resistance, phase).

4. Conclusion

The proposed algorithm allows:

• To research the character of variation of the differences between the precise and relative meanings of the characteristics;
• And for the extension with aim measuring the flow of modulated signals through oscillating circles;
• And for modification for researching the reaction of the oscillating circle as a chain with diapason of the input influence with strictly defined parameters

REFERENCES

1. Зернов Н.В., Карпов В.Г.; “Теория радиотехнических цепей”; Издателство “Енергия”, Ленинград, 1972г
2. Иванов Т. И., Пеловски Б. Т., “ Теория на радиотехническите вериги и сигнали”, издателство на Министерството на отбраната “Св. Георги Победоносец”, София, 1995
3. Димитров Й., Шойкова Е., “ Теория на електронните схеми”, изд. “Техника” 1989
4. Боянов Й., Райковска Л., Фурнаджиев в., “Автоматизация на проектирането и конструирането в електрониката”, изд. “Техника” 1991