SU1239612A1 - Device for measuring amplitude of recurrent pulses - Google Patents

Abstract

The invention can be used to measure the amplitude of periodic pulses. The purpose of the invention is to increase the measurement accuracy by compensating for the effect on the measurement result of the temporal parameters of a pulse sequence, such as a duty cycle. The amplitude meter contains a differential amplitude discriminator 1, a synchronization unit 2, a charge-discharge current shaping unit 3, a storage capacitor 4, a feedback amplifier 5, a measuring device 6. A reverse feedback resistor 7, a converter, are added to it. 8, the voltage is the current integrator 9. The discriminator 1 may contain a matched pair at transistors 10, resistors 11 and 12, and a tunnel diode 13. Before taking measurements, connect the discriminator's signal input 1 and its output, a constant voltage is applied to them, and the converter 8 is adjusted so that the voltage drop across the resistor 7 is zero. Il. with (L tsD Od QD O 1C

Description

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This invention relates to the field of

electrical measurements and can be used to measure the amplitude of periodic pulses,

The purpose of the invention is to improve the accuracy by compensating for the effect on the measurement results of the temporal parameters of the pulse sequence, for example, the duty cycle.

The drawing shows an electrical diagram of an amplitude meter. Pulses.

The meter contains a differential amplitude discriminator 1, the signal input of which is connected to the input bus, and the output is connected to the first input of the synchronization unit 2, the output of which is connected to the storage capacitor 4 through the charge-discharge current generating unit 3. The other input of the synchronization unit 2 is connected with sync bus. The input capacitor 5 is connected to the storage capacitor 4, the output of which is connected to the measuring device 6 and through the feedback resistor 7 to the feedback input of the discriminator 1 and to the output of the voltage converter 8 - current, the input of which through the integrator 9 is connected

with an additional output of the discriminator 1. The discriminator 1 can contain, for example, a matching pair of 10 transistors whose emitters are connected to a current source, and each of the collectors, respectively, through the first 11 and second 12 resistors to the staging bus. The base of the first transistor of the pair 10 is connected to the signal input of the discriminator 1, and the first resistor 11 is shunted by a tunnel diode 13. The collector of the first transistor of the pair 10 is connected to the output of the discriminator 1, the base of the second transistor is connected to the first feedback input, and its collector - with the second feedback input of the discriminator 1.

The pulse amplitude meter operates as follows.

The measured impulse signal Uy is fed to the signal input of the differential amplitude discriminator 1, in which the amplitude of the pulses is compared with the constant voltage coming from the output of amplification feedback 5 through the resistor 7 to the feedback input of the discriminator 1. If the amplitude of the input

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impulseB exceeds the feedback voltage by the order of units or fractions of millivolts, then the threshold element of discriminator 1, for example, tunnel diode 13; forms a standard impulse arriving at the input of the synchronization unit 2, to the other input of which a synchronizing impulse is supplied, upon receipt of which in the sync unit 2, a strobe pulse is generated. If from the output of discriminator 1 a standard impulse arrives at synchronization unit 2 for the duration of the gating pulse, then according to the signal of the synchronization unit 2, the charging current-discharge unit 3 of the base current formats the charging current of the storage capacitor 4 If for the duration of the gating pulse There is no standard pulse, then block 3 generates a discharge current of the storage capacitor 4. The voltage on the storage capacitor 4 is amplified by the feedback amplifier 5 and measured by measuring device 6, and Also, through the feedback resistor 7 is fed to the feedback input of the discriminator 1. Due to the negative feedback some time after the pulses are input to the meter, a dynamic equilibrium mode occurs, in which the constant voltage of the storage capacitor is proportional to the amplitude of the input capacitors: pulses. At the additional output of the amplitude discriminator 1, a voltage is formed that is proportional to the power dissipated in the transistor: 10 matched pair of 10 transistors connected to the feedback circuit. This voltage is averaged by the integrator 9, and then through the converter 8, the voltage is converted into a current flowing through the feedback resistor 7. This current creates an additional voltage drop on the resistor 7, which is algebraically summed with the feedback voltage. The power dissipated by the transistors of the matched pair of 10, included in the feedback circuit, depends on the time of the pulse characteristics of the input signal (duty cycle). For this reason, the additional voltage drop across the feedback resistor 7 depends on the duty ratio. So in

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pulse amplitude meter the output voltage is corrected in accordance with changes in the duty cycle of the measured signal, which provides an increase in the measurement accuracy of about 10 times.

Before the measurements are made, the meter is set up, at which the signal input of the discriminator 1 and its feedback input are connected, the DC voltage is fed to them and the voltage converter 8 - the current is adjusted so that the voltage drop across the feedback resistor 7 would be zero.

Claims (1)

Invention Formula A measuring instrument of amplitude of periodic impulses, containing differential amplitude discriminator. Editor L.Gratillo Compiled by A. Puchkovsky Tehred O. Sopko Proofreader M. Maksimishinets Order 3390/44 Circulation 728 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 , Production and printing company, Uzhgorod, st. Project, 4 five 0 five 0 124 the signal input of which is connected to the input bus, and the output is connected to the first input of the synchronization unit, the second input of which is connected to the synchronization bus, the charge-discharge current generating unit, the input of which is connected to the output of the synchronization unit, and the output to a storage capacitor and a feedback amplifier to a measuring device, characterized in that, in order to increase accuracy, a feedback resistor, an integrator and a voltage converter — a current — are introduced into it, while the integrator input is connected to an additional the output of the discriminator, the output to the input of the voltage converter — the current of which is connected to the feedback input of the discriminator and through a feedback resistor to the output of the feedback amplifier.