SU417900A1 - - Google Patents

Description

one

The invention relates to the field of instrumentation and conversion technology and can be used to build a measuring frequency and repetition period of electrical signals in centralized control systems, to interface the outputs of an object with the input of a digital machine, etc.

Devices are known that contain a series-connected differentiating device and a converter of mean values.

A necessary condition for interfacing analogue converters with digital gauges, controllers and computers is the linearity of the transfer characteristics of the analogue converter. Therefore, despite the fact that the period T and the frequency f are related to the unambiguous dependence T- / f (i.e., the magnitude / contains the complete information about the origin of T and vice versa), for the linear transformation G and f to the voltage applied separate, conversion devices built according to different principles. Two conversion units are required to measure (convert) a period and a frequency, which increases the amount of equipment consumed, the weight and size of the system. The known devices do not provide for the use of one converter (for example, a frequency converter) for linear conversion of another parameter (for example, a period). A change in the amplitude of the input signal (if special measures are not taken, which complicate the circuit of the device) causes an additional error. The purpose of the invention is the linearization of the reproducibility characteristics when the device is operating in period and frequency conversion modes.

and elimination of the error due to changes in the amplitude of the input signal.

This is achieved by the fact that a switch and a multiplier-dividing device, a divider and a multiplier, are introduced into the device.

the inputs of which, when operating in the period conversion mode, are connected via a switch to the outputs of the transducers of the mean and amplitude values, and one more multiplying input of the multiplier device is connected to the reference voltage source.

Circuit converter of the period and frequency of electrical signals to the voltage shown in the drawing.

The converter contains a differentiating device 1, a linear converter 2 of alternating voltage into a constant level amplitude value (amplitude value converter), a linear converter 3 alternating voltage into a constant level level of average value (converter of average values), switch 4 operating modes , the multiplying-divi- sion device 5, the source 6 of the reference constant voltage. The input signal n (i) (t) is fed to the input of the differentiating device 1 and to the input of the converter 2 amplitude power devices. The output signal of the differentiating device is converted by means of the 3 non-rectified values converter into constant current. When operating in the period conversion mode T of the signal. The switch of 4 operating modes is in the lower (according to the drawing) position, i.e. a constant voltage proportional to the amplitude of the input signal from the output of the amplitude converter, is fed to the first multiplying input, and the signal from the output preovers: explorer of average values - to the separating input of the multiplier-separating device 5. When operating in the frequency conversion mode (switch 4 is in the upper position), the direct voltages from the outputs are The amplitude and mean value values are passed through the mode switch to the dividing and multiplying inputs of the multiplier-dividing device, respectively. The second multiplier input of the multiplier-separating device passes the signal UQ from the source of the reference voltage. The voltages at the outputs of converters 2 and 3 are determined by the expressions U, S, .U, - U, -2.S, UJ. The transfer characteristic during device operation in the period and frequency conversion modes is determined by the expressions .., 7 ,. -out - - с and г, 2-f.Wz JJ UpUs - ГГ where 5i and Sz - transfer coefficients of converters 2 and 3; t is the time constant of the differentiating device 1. The coefficient is determined by the shape of the initial voltage curve and for each family of curves is a constant value. For example, for sinusoidal signals e (/): sinco / coefficient. Thus, the device has a linear transfer characteristic when operating in a period conversion mode and a frequency conversion mode. The subject of the invention A period and frequency converter of electric signals to a voltage containing a source of reference voltage, a series-connected differentiating device and a converter of average values, an amplitude value converter, whose input is connected to an input of a differentiating device, characterized in that in order to linearize the transmission characteristics when the device operates in the period and frequency conversion modes and eliminate the incidence of a change in the amplitude of the input On the signal, a switch and a multiplying-dividing device are introduced into it, the divider and multiplier inputs of which, when operating in the period conversion mode, are connected via a switch to the outputs of the transducers of the average wired and amplitude values, and one more multiplier input of the multiplying device.