SU875584A1

SU875584A1 - Modulator

Info

Publication number: SU875584A1
Application number: SU802889258A
Authority: SU
Inventors: Николай Петрович Сергеев; Владимир Викторович Музалев; Константин Николаевич Шишканов; Сергей Александрович Слюсарев; Владимир Александрович Елисеев
Original assignee: Пензенский Политехнический Институт
Priority date: 1980-02-25
Filing date: 1980-02-25
Publication date: 1981-10-23

Description

(54) МОДУЛЯТОР(54) MODULATOR

I.I.

Изобретение относитс к измерительной технике и может быть использовано в аппаратуре автоматического измерени , где необходима разв зка между источником сигнала и измерительными цеп ми, например когда злектроды дагшка дл измерени электрическогеГ пол должны быть изолированы от цепей питани измерительной схемы..The invention relates to a measurement technique and can be used in automatic measurement equipment, where isolation between a signal source and measuring circuits is necessary, for example, when the electrode circuit for measuring electrical field must be isolated from the supply circuit of the measuring circuit.

Известен модул тор посто нного тока, содержащий последовательный и параллельный ключи, трансформаторы и регулируемые резисторы дл компенсации переходных процессов и остаточных напр жений 1.A known DC modulator contains serial and parallel switches, transformers and adjustable resistors to compensate for transients and residual voltages 1.

Недостаток этого модул тора заключаетс в низкой точности преобразовани , обуславливаемой низкой степенью компенсации напр жений паразитных выбросов, характеризуемых остаточными параметрами транзисторов.The disadvantage of this modulator is the low conversion accuracy due to the low degree of compensation for the parasitic surge voltages, characterized by the residual parameters of the transistors.

Известен также модул тор, содержащий управл ющий и нагрузочный трансформаторы, четы|ж токозадаюишх резистора и четыре коммутирун 111их элемента, причем токозадающие IWDHciopi.i нключсны в базовые цепи коммуiMpyKitiiHx июментов, попарно соединенныеAlso known is a modulator containing a control and a load transformer, four current-supplying resistors, and four commutators of their 111 elements, the current supplying IWDHciopi.i being included in the basic circuits of communiMpyKitiiHx junctions, connected in pairs

коллекторы и Ьазовые цепи коммутирующих элементов подключены ко вторичным обмоткам управл ющего трансформатора, а попарно соединенные эмиттеры коммутирующих элементов подключены к дифференциальным первичным обмоткам нагрузочного трансформатора 2.the collectors and the laser circuits of the switching elements are connected to the secondary windings of the control transformer, and the pairwise connected emitters of the switching elements are connected to the differential primary windings of the load transformer 2.

Недостатком известного модул тора вл етс низка точность преобразовани , завис ща от остаточных параметров коммутирующих The disadvantage of the known modulator is the low conversion accuracy, depending on the residual parameters of the switching

10 элементов и межвитковой емкости трансформатора , обуславливающих паразитные выбросы напр жени в нагрузке.10 elements and interturn capacitance of the transformer, causing parasitic voltage surges in the load.

Цель изобретени - повыщение точности преобразовани путем компенсации паразитных The purpose of the invention is to increase the conversion accuracy by compensating for spurious parasitic

15 выбросов напр жени .15 voltage spikes.

Поставленна цель достигаетс тем, что в модул торе, содержащем управл ющий и нагрузочный трансформаторы, два токозадающнх резистора и четыре коммутирующих элемента, The goal is achieved by the fact that in a modulator containing a control and a load transformer, two current-supplying resistors and four switching elements,

Claims

20, the first and second inputs are connected to pairwise connected collectors of switching elements — the first with the second and third with the fourth, respectively, and through current supplying resistors to the middle terminals of the secondary windings of the control transformer, whose extreme terminals1 1 are connected to the bases of the switching elements, and the terminals of the primary winding of the load transformer connected to pairwise connected emitters of switching elements - the first with the fourth and the second with the third, respectively. The drawing shows the principal scheme of the proposed modulator. The modulator contains a control transformer 1 with secondary windings 2 and 3, the first, second, third and fourth switching elements 4-7, respectively, the current setting resistors 8 and 9, the load transformer 10 with the primary winding And, the first and second inputs of the module tori are connected to pairwise connected collectors of the first 4, second 5, third 6 and fourth 7 switching elements, respectively, and through the current-setting resistors to the middle points of the secondary windings 2 and 3 of the control transformer 1, the beginning and of which coils The beginning and end of the primary winding 11 of the load transformer 10 are connected to the pairwise connected emitters of the switching elements 4 and 7 and 5 and 6, respectively, and the beginning and end of the secondary winding 12 of the load transformer 10 are the outputs of the modulator . The modulator operates as follows. The primary winding of the transformer 1 receives oscillations of the reference frequency of the control signal, which cause the appearance of voltage oscillations on the secondary windings 2 and 3. In the first half-period of oscillations of the secondary windings 2 and 3 of the control transformer, a voltage is applied that opens the switching elements 4 and 6 , as a result, a circuit is formed for the flow of current of the converted signal V gy, i.e. the first input of the modulator - switching element 4 - winding 11 of the transformer 10 - switching element 6 - the second input of the modulator. In the second half-period, the oscillation of the control signal is repeated, only in this case, the switching elements 5 and 7 are open and the current in the winding 11 flows in the opposite direction. Thus, the switching of controllable switching elements makes it possible to convert a constant voltage to an alternating voltage. Since the windings of transformer 1 have an interturn capacitance, and the switching elements 4-7 have residual parameters, when switching the latter at points Q, parasitic pick-up voltages occur, which are well observed in the absence of an input signal. Emission voltage ti -.- F .. jj t where f is the magnetic flux created by the winding 11 of the transformer 10; CSJ is the number of turns in the secondary winding of the transformer 10. Since these emissions occur synchronously and in-phase at points O and b, they are compensated for. Thus, the organization of new connections in the modulator makes it possible to significantly reduce the conversion error, depending on the residual parameters of the switching elements and parasitic voltage surges in the load, without significantly complicating the modulator circuit. Claims of the invention A modulator comprising a control and a load transformer, two current-setting resistors and four switching elements, characterized in that, in order to improve the conversion accuracy by compensating for parasitic voltage spikes, its first and second inputs are connected to pairwise connected collectors of the switching elements. - the first with the second and third with the fourth, respectively, and through, the current-setting resistors to the middle terminals of the secondary windings of the control transformer, the outermost, the terminals of which are connected to the bases of the corresponding switching elements, and the terminals of the primary winding of the load transformer are connected to pairwise connected emitters of the switching elements - the first fourth and second with third respectively. Sources of information taken into account in the examination 1. USSR author's certificate number 478410, cl. H 03 S 1/42, published. 07.07.75. .

2. Kalinchuk B. A. and Pichugin O. A. Semiconductor modulators. L., Energie, 1969, p. 56-57, fig. 52 (prototype).

P