Voltech AT360, Руководство пользователя

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V
OLTECH
AT
I
U
SER
M
ANUAL
P
AGE
7-85
7.1.20 LBAL – L
ONGITUDINAL
B
ALANCE
Measurement
Range
Test
Voltage
Test
Frequency
Basic
Accuracy
0 dB to 100 dB 1mV to 5V 20Hz to 3MHz 0.5dB
Longitudinal balance is a measure of the common mode rejection ratio
(CMRR) of a transformer. That is, the ability of the transformer to reject
unwanted noise signals that are common to both input terminals with
respect to a common point.
An ideal transformer would have infinite CMRR (Vout1 = 0). In practice
differences in symmetry of transformer construction mean that input
common mode signals appear as unwanted output voltages.
See also the GBAL test.
Where Used
The longitudinal balance test is used to confirm the CMRR of audio and
telecommunications transformers that are designed to be connected to a
balanced line. The test ensures that the transformer will reject common mode
noise signals as required in use. Faults in the placement of windings or core
may be detected using this test.