SU30346A1 - amplitude voltmeter for high quality measurements - Google Patents

Description

In radio engineering practice, it is often necessary to measure the amplitude of an alternating voltage at different ranges of high frequency. Existing lamp voltmeters do not have this property, being limited to relatively narrow limits of measured frequencies. In addition, they require batteries for power supply and usually distort the measurement in order to create some load for the object being measured.

The present invention aims at eliminating all the aforementioned disadvantages by using an amplitude voltmeter for high-frequency measurements, consisting of an electrostatic measuring device connected in series with a rectifier. As the latter, in order to eliminate harmful capacitance, a photocell was used, illuminated either by day or artificial ceeToiyi. The drawing shows a diagram of a voltmeter,.

Terminals connected between co6of9 are connected to terminals A-B to measure the voltage source to be measured.

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Photocell F and static voltmeter. The applied voltage will be rectified by the photocell F, and this rectified current will charge the voltmeter Y to the maximum voltage E. Next, the current through the photocell will almost completely cease or it will leak only the leakage between the terminals of the static voltmeter, which, generally speaking , insignificant. Thus, immediately after charging the voltmeter, the device will be a clean capacitance composed of two series-connected capacitors of the photocell and a voltmeter. The capacity of the photocell is significantly less than the capacity of the voltmeter and therefore the total capacity will be approximately equal to the capacity of the photocell (about 2 to 8 centimeters or less with special manufacture of the photocell).

The photocell and the voltmeter can be assembled in one case, and it is possible to use either daylight or artificial lighting to illuminate the photocell, for example, when it is mounted on a static voltmeter electric lamp.