SU375585A1 - TRANSFORMATION METHOD ^? C1-PARAMETERS IN FREQUENCY - Google Patents

Description

one

 The known methods of converting RCL parameters into frequency, based on the frequency balancing of bridge circuits, in which the 7 C-elemeites studied are included, have a long time for setting the frequency at their output.

Methods for converting CL-parameters to frequency, based on the use of transients in the integrative Sealy L-chain x, have an inversely proportional dependence of frequency on CL-napmeter.

The purpose of the invention is to obtain a linear conversion function at high speed.

This is achieved by applying a linearly varying voltage to a differentiating circuit with a constant time Tx containing the R, C or L element under study, and a rectangular pulse at the output of the differentiating circuit, the amplitude of which is determined by the value of the converted quantity integrate

// -. dU.

diff -

dt

  R

dt - s,

and,

Tj

diff

t

where m is the integrator time constant.

At the moment of equality of the integral to a certain value, the voltage supplying the differential circuit is switched, i.e., if a linearly increasing voltage is first applied, then a linearly falling voltage / 1 / n - kt is applied, where Un is the threshold voltage.

After switching the linearly varying voltage, the polarity of the rectangular pulse at the output of the differentiating circuit is reversed. This pulse is also integrated to a certain value of the integral, after which the linearly varying voltage is again switched to the opposite, and the conversion cycles are repeated.

Since the amplitude f / diff of the pulses at the output of the differentiating circuit is directly proportional to the time constant Tx equal to RC or LIR, i.e. proportional to the parameter being transformed, and the integrator charge time to a certain value Un is inversely proportional to the input voltage t / diff of the integrator , the frequency of the integrator charge-discharge cycles is directly proportional to the / CL parameter being transformed. Indeed, at the moment of equality of the output voltage of the integrator / „„ t to the threshold

f / n (3, f -JL-j if / n) Fig. 1 shows a block diagram of a device for carrying out the method; Fig. 2 shows timing diagrams explaining the method. The device consists of a differentiating circuit 1 (e.g. RC - or RL-nenn), integrator 2, comparing device 3 and triangular voltage controlled generator 4. Linearly increasing voltage, Fig. 2, a, from the output of generator 4 goes to differentiating circuit 1. Positive pulse, Fig. 2, b, the voltage at the output of the circuit 1 is integrated by the integrator 2. At the moment of equality of the voltage, Fig. 2, c, at the output de-integrator threshold voltage Ua, a comparison device 3 is triggered, which outputs a signal to generator 4. As a result, generator 4 is output to generator 25. As a result, linearly falling voltage is output from generator 4, and negative pulse from circuit / polarity. At the moment when integrator 2 is discharged to another threshold level f / n, 30 comparing device 3 is triggered again, and a linearly increasing voltage is output from generator 4, etc. Switching frequency of generator 4 (Fig. 2, d) is proportional to the measured parameter. 5 10 15 Ha FIG. 2 dotted line shows the case when the value of the converted CL-parameter has increased. At the same time, the amplitude of the pulses at the output of the differentiating circuit / and the integrator charge rate increased and the comparator operated earlier, i.e., the output frequency of the converter increased. This method can also be used to convert the signals of differential C1, sensors and bridge sensors to the frequency. To do this, the differential sensor must be included in the bridge differentiation circuit and the unbalance signal of the bridge must be integrated. The subject of the invention is a method for converting parameters into frequency, based on using processes in an RC or i / L circuit with a periodic disturbing effect, characterized in that, in order to obtain a linear conversion function at high speed, the element whose parameter is converted to the frequency is included in the differentiating circuit, to which the linearly varying voltage is applied, and the resulting voltage is integrated until the integral is equal to a certain value; Edit yuschees eg l ix and integrating the voltage of a reverse polarity at the output of the differentiating circuit to a certain value of the integral.

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