SU444126A1 - Device for comparing two alternating voltages in phase - Google Patents

Description

The invention relates to the field of phase-measuring technology and can be used to create wide-range phase meters. Known devices for comparing two alternating voltages in phase, containing two tsars of blocks of daodny comparison circuits, which form two adjacent arms of the bridge circuit, and intermediate transformers, have uneven sgnal and significant errors due to the dependence of the measurement result on the ratio of the values of the compared stresses. The purpose of the invention is to reduce the dependence of p measurement results on the ratio of amplitudes of the compared voltages and obtain a uniform scale devices. This is achieved by the fact that the device is equipped with a sensitive element that reacts to the medium and the polarity of the signal, and the source of the compared voltage is connected to both adjacent blocks of diode comparison circuits, one of which with reverse polarity. The drawing shows a block circuit devices. It contains blocks of diode circuits of Comparison 1-4, of which the diodes include 5.6 and active resistances 7, the sensitive element 8, consisting of identical linear active resistances 9 and the frame of the magnetoelectric device 10, the intermediate transformer II of the reference voltage and intermediate transformer 12 of measured voltage. The device works in the following way,

While in block I there is an instantaneous value of reference 1 voltage UT from a transformer. More than an instantaneous value of the measured voltage But from transformer J2, in block I, diode 6 is closed, At the same time, diode 6 in adjacent block 2 is closed, because it has the voltage Uj, and the voltage tf2 gives-,

with in a non-conductive direction. As a consequence, the current through the frame of the magnetoelectric device 10 is zero. If, in block I, the voltage Uo exceeds the voltage CT, then the diode 6 opens in this block, and diode 5 closes and the current flows through the frame of the device 10. When the voltage Uo in block 2 is supplied in the conducting direction (and in block I in the non-conducting) and exceeds Ur, diode 6 opens in block 2 and a current flows through the frame of the device 10 in the negative direction. In the following - js voltage half-period Uj, a similar process occurs in blocks 3 and 4.

The deviation of the arrows of the magnet ole-; l) tric-tic device is proportional to the average value of the current for the period occurring in its frame. At a constant ratio of the amplitudes of the measured eivioro and the reference voltages

() the deviation of the arrow of the magnetoelectric device at the device output is proportional to the deviation from the phase angle angle equal to 90

PREFERRED INVENTION

A device for comparing two alternating voltages in phase, containing two pairs of blocks of diode comparison circuits, each of which forms two adjacent arms of a bridge circuit, and intermediate reference and measured voltage transformers, in order to reduce the dependence of the measurement result on the ratio of the amplitudes of the compared stresses to obtain a uniform scale, it is equipped with a sensitive element containing active linear resistances and a magnetoelectric device, the frame of which is connected It is connected to the output diagonal of two bridge circuits and through the named resistors to the midpoint of the secondary winding of the intermediate transformer of the reference voltage, and the two secondary windings of the intermediate transformer of the measured voltage are connected to both adjacent blocks of diode equalizer circuits, and to one of them reverse polarity.

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