SU789912A1 - Apparatus for measuring nonlinearity of saw-tooth voltage - Google Patents

Description

connected to the synchronization input of the device, the output of the pulse tip selection unit is connected to the second input of the comparator and through the nonlinearity sign detector to the display unit, and the output of the pulse generator .adjustable duration is connected to the second input of the prohibition element JCO. FIG. 1 shows a functional diagram of the device / in FIG. Figure 2 shows the main oscillograms explaining the operation of the device. The functional diagram of the device includes a differentiating cascade 1 connected to the input of the device, an amplitude detector 2 and a pulse tip selection unit 3 connected to the output of the differentiating stage, a generator of 4 pulses of adjustable duration connected to the synchronization input of the device, a counter of 5 pulses and connected to it in series indication block b, gene7 connected to the output of the amplitude detector 2 and the synchronization input, comparator 8 connected to the outputs of the gene 7 and block 3 of the pulse tip selection, ale The prohibition element 9, connected to the outputs of the generator 4 pulses of adjustable duration and comparator 8, de; the tector 10 of the sign of the measured value connected to the output of block 3 of the selected pulse peak and the input of block 6 of indications. The device works as follows. In working condition, a controlled voltage S of voltage is applied to the input of the differentiating cascade. At the same time, at the input of the pulse generator 4 pulses of adjustable duration, synchronization pulses appear that determine the pulse repetition frequency of the sawtooth voltage. At the output of the differentiating cascade, pulses of a rectangular shape Ua (Fig. 2) appear, the amplitude of which is proportional to the rate of increase of the input voltage Unf and the decay of the peak corresponds to a change in this speed, i.e. characterizes the non-linearity of the sawtooth voltage during the forward stroke Un I and the output of the amplitude (peak) detector 2 appears a constant voltage proportional to the maximum speed Un. This voltage goes further to one of the inputs, block 3 of the top of the differentiated pulse (difference an amplifier with a constant gain), a differentiated pulse from the output of differentiating cascade 1 is fed to the other input of this block. In the selection block, the incoming signals are subtracted This leads to a constant voltage gain, resulting in a voltage pulse U-j. 2), repeating the shape of the top of a differentiated pulse. The gain of the difference amplifier is selected from the following ratio, where 7 is the maximum value of the measured nonlinearity in relative units. So, for a given maximum nonlinearity of 0.1 10, at 0.01 Kch, with 100. If it is necessary to divide the scale of measured nonlinearities into several subranges, this means that one should choose several fixed values. gene 7 works in conjunction with a binary counter. The voltage supplying the resistive matrix of the generator is used as the voltage from the output of the amplitude detector, which is proportional to the rate of change of the sawtooth voltage, i.e. equal to the amplitude of the differentiated pulse. A step voltage is generated at the output (Fig. 2, the magnitude of each step of which is directly dependent on the magnitude of the maximum speed of the measured GF. Moreover, each step is formed synchronously with the pulses of the GF input to the device. Cycle measuring the nonlinearity, the PN ends after the formation of the maximum selected number of steps, for example, the 12th output of the gene, the 7th step voltage is applied to one of the inputs of the comparator 8, compared with th vertex pulses from the output of the differential amplifier 3 to another input of the comparator (Fig. 2). The pulses u8 (fng. 2), generated by the comparator 8 at the time of the step-to-peak comparison, go to one of the inputs of the prohibition element 9. To the other input The prohibition element 9 receives impulses 04 (Fig. 2) from the output of generator 4, having a minimum duration slightly longer than the return stroke of the PN. Thus, the comparison pulses of the next voltage level from gene 7 to the top of the differentiated pulse arriving at the moment reverse, not the arrival of the counter 5 pulses. Comparison pulses, received for the period of the forward run of the PN, come from comparator 8 through element 9, prohibiting counter 5 (Uq of Fig. 2) and further to display unit 6. If the magnitude of the step in wH is equal to 1% of the magnitude of the voltage of the amplitude detector proportional to the maximum rate of change of the PN, then the number of steps that fit in the amplitude of the peak pulse is the nonlinearity coefficient in percent, determined by the known formula I. UntYigx-bnniin u.U

. U

and:

n ir (ax nma) To measure the magnitude of the nonlinearity of the PN in a separate selected section of the forward stroke, it is necessary to change the duration of the inhibit pulses coming from the generator of 4 pulses of adjustable duration. In Fig. 2, the change in the duration of the pulses U is shown by a dashed line.

A detector 10 of the sign of the measured nonlinearity coefficient of the signal is supplied from the output of the vertex extraction unit 3 (differential amplifier). Here, differentiated and strengthened. As a result, a negative pulse is obtained at the output. With a positive nonlinearity coefficient (i.e., when the rate of change at the beginning of the PN is greater than at the end), and positive, when the nonlinearity coefficient is negative. The pulses from the output of the amplifier of the sign detector go on to the corresponding indicator, for example, the LED in the display block b.

The high speed of measurement and direct measurement of the measured value in digital form will completely automate the measurement process and apply the proposed device to control the non-linearity of commercially available generator sweeps for television and other devices.

invention formula

A device for measuring the non-linearity of the sawtooth voltage, containing a pulse generator of adjustable duration, connected to the synchronization input of the device, a serially connected pulse counter and a display unit, as well as a differential stage whose input is the input of the device and its output connected to the amplitude detector and block inputs extracting the top of the pulse, differing in that, for the purpose of automating

0 of the process of measuring and speeding up, a nonlinearity sign detector, a step voltage generator, a comparator and an inhibition element are entered into it, the output of the inhibition element is connected to the input of the pulse counter, and its first input is connected to the output of the step voltage generator the first input of which is connected to the output of the amplitude detector and to the second input of the pulse pickup unit, and the second input of the step voltage generator is connected to the synchronization input of the device, s stroke pulse peak isolation unit is connected to the second input of the comparator and across the sign of the nonlinearity detector to the display unit, and vlhod variable duration pulse generator connected to the second

0

entry ban item.

Sources of information that are taken into account in the examination of 35 1. USSR author's certificate

 521530, class CiOlR 29/02, 25.09.72. :; 2. Olinokov V.F. The gauge is non-linear. Sawtooth voltage. Measuring equipment, 1974, No. 9, 40 b. 74-76 (prototype).

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fig 2

Claims (1)

Claim An apparatus for measuring neliney'nosti sawtooth, co- _h dd keep controlled the duration of the pulse generator connected to the input of a synchronization device, a serial pulse counter and display unit as well as differentiator stage, the input of which is the input device, and its output is connected to the inputs an amplitude detector and a pulse peak extraction unit, characterized in that, in order to automate the measurement process and increase speed, a nonlinear sign detector is introduced into it In this case, the step voltage generator, the comparator and the inhibit element, the output of the inhibit element connected to the input of the pulse counter, and its first input through the comparator connected to the output of the step voltage generator, the first input of which is connected to the output of the amplitude detector and to the second the input of the unit for selecting the top of the pulses, and the second input of the step voltage generator is connected to the · synchronization input of the device, the output of the unit for selecting the top of the pulses is connected to the second input of the comparator and through a nonlinearity sign detector is connected to the display unit, and the output of a pulse generator of adjustable duration is connected to the second input of the inhibit element.