SU77723A1 - Amplitude Voltmeter - Google Patents

Description

The subject of the invention is an amplitude lamp voltmeter for separately measuring voltages of different polarities.

Amplitude lamp voltmeters, which are widely used in measurement technology, have the disadvantage that when measuring with impulse voltages of different polarity, it is necessary to change the input diode poles, which makes it difficult, especially in further applying voltage to the DC amplifier. current, do not allow its high resistance in the input circuit. On the other hand, with long duration pulses in order to reduce the error, it is necessary to have a large input resistance.

In addition, in conventional devices, measurement errors occur due to the dc component of the input circuit having a constant component voltage.

The proposed amplitude voltmeter is free from the indicated drawbacks, since the diode of the voltmeter is always switched on by the self-cathode in the grid circuit of the amplifying lamp or

to the input of the DC meter.

The drawing shows a diagram of the proposed amplitude voltmeter for separately measuring the pulse voltages of both polarities.

In order for the amplitude voltmeter to work properly, it is necessary to select the resistance values RI and capacitance C, so that the time constant i C is sufficiently large compared to the pulse duration and the capacitor Cj does not have time to charge through the resistance RI. Otherwise, if pulses of a different polarity are contained in the measured pulses, on the resistance RI, pulses of opposite polarity will appear, for which diode D will be opened. The constant time R c. Should not be excessively large compared to the intervals between pulses, since otherwise a constant voltage cut-off and zero-line offset will occur. This will lead to the inequality of the amplitudes of the pulses of both polarities at the resistance Ri and the amplitudes of the input voltage of the pulses.

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The work of the voltmeter proceeds as follows.

Diode D charges the series-connected capacitors C and Ca to a common voltage equal to the amplitude of the pulse of the measured field; p1, with a gradual redistribution of the voltages between them until the capacitor Cf due to the difference in the discharge time constant amplitude value. This voltage value is applied either to a DC current meter or to the input of a DC amplifier with a measured output device.

SUMMARY OF THE INVENTION Amplitude voltmeter for separately measuring pulsed voltages of different polarities, characterized by the use of two series-connected capacitors, each bridged by a separate constant resistance, in order to gradually redistribute the voltages between the capacitors due to the difference in the time constant of their discharge circuit one of them is not charged to the full amplitude value of the voltage measured by the device connected to the capacitor terminals.