SU488224A1 - Logarithmic function converter - Google Patents

Description

one

The invention relates to analog computing and can be used to implement various non-linear signal conversions.

A logarithmic functional converter is known that contains a summer, the first input of which is connected to the modulator, one of the inputs of the modulator is connected to a sinusoidal voltage source, and the other input is connected to an input source and a comparison unit.

The disadvantages of the known converter are the circuit complexity, the cumbersome sequence of functional transformations, and the impossibility of obtaining an anti-logarithmic dependence of the output signal on the input signal.

In order to simplify the device and expand the class of problems to be solved, two voltage-phase converters are added to it, the first inputs of which are connected to the output of a sinusoidal voltage source, the second input of the first voltage-phase converter is connected to the output of the comparison unit, and the outputs of voltage converters through the adder is connected to the first input of the comparator unit, the second input of which is connected to the output of the sinusoidal voltage source.

The drawing shows a block diagram of a logarithmic functional converter.

It consists of a sinusoidal voltage source (generator) 1, an input signal modulator 2, an adjustable voltage-phase converter 3, an unregulated voltage-phase converter 4, an adder 5, a comparison unit 6.

The operation of the converter is based on the use of algorithms obtained by approximating the dependence proportional to the logarithmic function y by the arc of a circle (y-VO) + (X-XO) R using the method of four selected points.

According to one of them, the sum of symbolic images of three sinusoidal stresses

i, -L, UK,

where i / o fixes the position of the center of the circle X0, PP Ux is proportional to the input signal and coincides in phase with the X axis; UR is equal to the radius of the circle R and has a phase defined by the condition

i.-i.

arg

and 2

equal to f / Mogx proportional to the input logarithm, and

Lf - L / logx +

where Ulogx is proportional to the input signal and coincides in phase with the Y axis; the UK phase is determined by the condition

yo and log x + and

to

arg

and log. equal to a voltage proportional to the antilog of the input signal. The input signal is converted by modulator 2 into a sinusoidal voltage, denoted Vx with a logarithmic and Ulogx with an anti-log conversion. The voltage from the output of source 1 is fed to the voltage-phase converters 3 and 4. Thanks to this, the output of the converter 3 is the voltage L / d and the output of the converter 4 is the voltage f / o. Their voltages (), UR and L / 0 are applied to the adder 5, the output of which forms the voltage U, -U, + UK with the logarithmic and f / o-f / 10g. with anti-log conversion. In the comparison unit 6, the voltage from the output of the adder and the output of the source 1 is mapped in phase. Moreover, the voltage at the output of source I coincides in phase with the voltage at the output of the modulator or differs by a constant value. At the output of the comparator unit, a signal is generated that is proportional to, for example, the cosine U, -U, with the logarithmic transformation 0 - log l: + th f / IOJJC

At the antilog transformation. It affects the parameters of the elements of the voltage-phase converter circuit 3, changing the phase UR. When this is achieved

and,

arg ig

Claims (1)

in the case of a logarithmic transformation and, accordingly, 0 - f) log - «+ / j in the anti-log transformation, the signal at the output of block 6 is zero, and the voltage at the output of the adder is equal to the logarithm of the input signal) at the logarithmic conversion, the anti-log of the input signal fy L / oi / log + i with anti-log conversion. The invention includes a logarithmic functional converter containing an adder, the first input of which is connected to the modulator, one of the inputs of the modulator is connected to a sinusoidal voltage source, and the other input is connected to an input source and the comparator unit, and extending the class of tasks to be solved, two voltage-phase converters are additionally introduced in it, the first inputs of which are connected to the output of a sinusoidal voltage source, the second input of the first The voltage transducer is connected to the output of the comparator unit, the outputs of the voltage transducers through the adder are connected to the first input of the comparator unit, the second input of which is connected to the output of the sinusoidal voltage source. / n .J Output Jl.