SU690504A1 - Integrator - Google Patents

Description

I

The invention relates to analog cpcjj, automation and computer equipment and can be used in electronic modeling devices and automatic control systems, for example, moving objects, when it is necessary to determine the value of a periodic function by the rate of change of its argument, in which is the value of this argument.

Integrating devices are known that contain two identical integrating capacitors, one of which includes a decoupling amplifier in the HC circuit, while the other is discharged to zero or to the boundary voltage U using an additionally inserted adder. Every time when the output signal of the amplifier reaches any of the indicated limits (O or BV), the capacitors are swapped using the control circuit of the integrating device. Thereby, a jump-like change in the output signal of the integrator 1 is provided.

The main disadvantages of such devices are the reduction in the possible scale of the output signal, the complexity of the control circuit, and the need for two precision capacitors, which increases the weight and size of the device. In addition, the difference in the actual deviations of the strengths of the two capacitors from the nominal may cause additional errors of integration, since these deviations cannot be compensated for by adjusting the resistance of the RC circuit resistor; This disadvantage can be eliminated by further complicating the circuit — the introduction of a second input resistor and switching elements of the input resistor.

The closest in technical essence to the proposed invention is an integrating device containing a storage capacitor, a charging current driver, whose input and output are the device input and output, respectively, and a two-level comparator whose input is connected to the output of the charging current generator and output. connected to the inputs of the reversible counter 2. The disadvantage of this device is also an underestimated scale of the output signal and, as a result, the accuracy is not high enough. In addition, the need for current-limiting resistors leads to a decrease in speed. The purpose of the invention is to increase the speed and accuracy of the device. The goal is achieved by the fact that the device contains an OR element connected in series to the corresponding plugs of the two-level comparator, a trigger with a counting input, and a switching unit whose switching terminals are connected respectively to the storage capacitor and to the current terminals of the charging current generator connected to the auxiliary non-switchable mode capacitor. . FIG. 1 is a block diagram of an integrator; in fig. Figures 2-6 show the versions of the formers (circuits or devices) of the charging current and the output signal. ; ..: The device contains a current driver and an output signal with input 2, output 3 to current outputs 4 and 5, storage capacitor 6, control unit 7, which includes a two-level comparator 8 times separate outputs, the element OR 9, a trigger 10 with a counting input and a switching unit 11. Integrating device can be. supplemented by a non-switchable capacitor 12, and in this case, a current-fringed redast 13 is introduced, as well as a reversible two-way counter 14. The former 1 of the charging current and output signal in the simplest form (Fig. 2) is prev: It is a passive center containing only the input Receiver 15 RC circuit, the output signal is then taken directly from the storage capacitor. Such a shaper can be applied only in cases where the input signal levels are many times greater than the levels of the output signal and the accuracy requirements are low. The accuracy of the operation of the formation of bodies can be somewhat improved by the introduction before the output of the buffer cascade of separation, or large-scale amplifier 16 (Fig. 3). A significant increase in accuracy is given by replacing the input resistor with a generator or current amplifier-17 (Fig. 4 and 5). The most advanced driver that provides high accuracy, is an il8 operational amplifier with an input resistor 15 (Fig. 6), the charging circuit of this driver is enclosed between

690504 output and input of the amplifier, i.e. is his feedback loop. It1 integrator works as follows. The installation chains of the initial value of the integral X0, which should not exceed the half-periods of ± ir (or ± 1 (1 + 6), where 5 "1, provide the necessary charge of the capacitor 6 in any of two states of block P. From the moment of disconnection of the circuits setting x0, the process of integrating the rate of change of the argument — the value x (t) represented by the signal and supplied to the input 2 of the driver 1 of the charge current and the output signal — begins. When the integral value (t) reaches + or -tg, the output signal level 3 shapers and compared to one from the trigger levels of the two-level comparator 8 set by the reference voltages ± Uo, and from the corresponding output of the comparator through the element 9 or the trigger 10 a discrete signal is received, from which the trigger changes its state and switches the block 11. connected to pin 4 of the imager, disconnected from it, and connected to pin 5, and the other capacitor lining, on the contrary, disconnected from pin 5 and connected to pin 4 of the imager. As a result of such a switch, the value represented by the signal taken from output 3 of the driver will change its sign, i.e. make a jump of 27g. If the integrator's input signal retains its sign, then the direction of the jumps will remain the same, and if the sign of the input signal changes from 1, then and. the direction of the next jump. The switchings described above must be made by the And block strictly synchronously, so that even short-term short circuits between the capacitor plates and the terminals 4 and 5 of the connection of the former 1 could not occur. If you specifically correct the absolute value of the levels, the comparator trips upwards to 7g (1 + 6), then stability of operation (exclusion of the possibility of the occurrence of the buzzer mode) will increase, since it will be guaranteed that when switching unit II, there will not be a condition in which, due to inaccuracy elements, same for cc reverse switching conditions. However, with this; By correcting the magnitude of the jump will be 27g (1 + 5) j, i.e. will not be equal to the period, but will exceed it, which is unacceptable; the inclusion of additional non-switchable capacitor 12 between outputs 4 and 5 of the former 1, whose capacity is many times smaller than the capacity of the main capacitor 6, will lead to a partial decrease in the absolute value of the voltage between points 3 and 4 Shaper 1 When switching the main air conditioner. This will reduce the magnitude of the jump and make it equal to 27g if the absolute value of the output signal after the jump is 7g (1-5), for which additional capacitor 12 should have a capacitance of Cd 5 Co, (1) where Co is the capacity of the main capacitor 6. Note that a slight increase in the range of signals generated by the integrator to ± 7g (1 + 5) may be useful from the point of view of setting the initial value of the integral, since the sources of the corresponding signals can also output them in a range slightly exceeding the exact value of one th period. It should be taken into account that the calculated value of the RC time constant of the integrator connecting the scales of the signals at its input and output must include the capacitance C of the parallel connection of capacitors, i.e. C Co (1 + 6) (2) The requirements for the accuracy of the operation of the additional capacitor 12, due to the small effect according to formula (2), can be significantly reduced compared with the requirements for the main capacitor 6. The weight and dimensions of the additional capacitor also many times smaller than the main one. Since the introduction of a non-interchangeable capacitor 12 causes a voltage jump not only at this capacitor, but also a small jump at the main capacitor, a current should be introduced into the second circuit; however, the resistance value in this case can be taken times less than in integrators working with a full discharge of an integrating capacitor. Therefore, the previously noted negative consequence of the introduction of a current-limiting resistor will not be significant. If the integrator introduces a reversible two-way counter 14, the inputs of which are added and subtracted will receive discrete signals from both outputs of the two-level comparator 8, then such a counter will count the period number N in which the value of the calculated argument of the periodic text is found. This expands the functionality integrator. In such a design, it can be used in combined (hybrid): computing devices in which a mixed digital-analog representation of variables is used, since the analog part of such a representation is a periodical function of the quantity represented. The effectiveness of the invention lies in the fact that the proposed integrator allows for unlimited integration time and at the same time to obtain the largest possible scale of the output signal. In addition, the stability of the integrator is guaranteed without compromising accuracy, and its functional capabilities are extended. Formula of the Invention An integrating device containing a storage capacitor, a charge current form, whose input and output are respectively the input and output of the device, and a two-level comparator, the input of which is connected to the output of the driver, and that, in order to improve the speed and accuracy of the device, it contains series-connected element OR, connected by inputs to the corresponding outputs of a two-level a comparator, flip-flop input and a switching unit, kommutatsiO1shye vshody which are respectively connected to the storage capacitor and TO-, yakov vgeodam shaper charge current, connected to an additional capacitor neperekp tea regime. Sources of information taken into account in the examination 1. The author's certificate of the USSR N 308436, cl. G 06 G 7/18, 1972. 2. Kogan B. Ya. Electronic simulators and their use for the investigation of automatic control systems, M., Fizmatshe, 1959, p. 77, fig. 306 (prototype).

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