Voltech ATi User Manual page 324

T T
ESTS AND EST
7.1.6 QL – Q
Measurement
Range
0.001 to 1000
When a transformer is energized, the changing magnetic field in the core
causes two types of losses: hysteresis losses and eddy current losses.
The total of these losses can be represented on the equivalent circuit of a
transformer by a resistance associated with the inductance of the
winding.
For this equivalent circuit the Quality Factor Q is defined as:
For a given inductance, the lower the equivalent series resistance, the
higher is the value of Q, i.e. the 'better' the coil.
Where Used
The Q factor test would normally be used for signal, pulse and switched mode
power transformers, where the normal operating conditions require only small
excursions of the B-H curve, never extending beyond the linear region.
P 7-26
AGE
C
ONDITIONS
F
UALITY ACTOR
1mV To 5V
Q = ω ω ω ω Ls
Rs
Test
Voltage Frequency
20Hz To 3MHz
ω ω ω ω = 2π π π π f)
(
where
Test
Accuracy
V AT U
OLTECH I SER
Basic
0.5%
M
ANUAL