STB8827
Series Operation Manual Chapter 5 Execute LCR Operation and Some Examples
61
When the measurement parameter is L2A-N, N is the turn ratio of primary to
secondary;
When the measurement parameter is L2B-N, N is the turn ratio of secondary
to primary.
NOTE:
STB8827
A is suitable for the measurement of turn ratio
when N
≥
1. If N<1, it may results in measurement error due to large
amplitude of the sampled signal. Therefore, please select L2A or L2B
reasonably before measurement.
In general, if the turn of winding A is larger than winding B, select L2A-N,
otherwise select L2B-N.
HINT:
After setting N-REF (
＞
1) in limit table, N or 1/N appears to be the turns
of transformer primary or secondary polarity directly. Refer to the setup of N-REF
in chapter 4.
5.6.3 Mutual inductance M
Mutual inductance adopts direct measurement method. After connecting the
transformer according to figure 5-17, mutual inductance can be measured when
the secondary parameter selects M.
Hcur
M
Hpot
A
B
Lpot
Lcur
Figure 5-19 Direct measurement method of mutual inductance
Similar to the measurement of turn ratio, if the turn of winding A is larger
than winding B, select L2A-M, otherwise select L2B-M.
5.6.4 Direct current resistance measurement R2, DCR
Select L2A-R2 to measure the primary inductance and primary direct current
resistance;
In LCR manner, select Ls-DCR to measure the inductance and direct current
resistance for some winding of transformer with four-terminal manner.
Whether it is L2A-R2, L2B-R2 or Ls-DCR, measurements are alternated
between AC/DC. As for the measurement of high resistance, especially large
inductance components, it may lead to unsteady measurement or test error due
to long stable period of signal.
STB8827
A supports DCR independent measurement. With constant
direct current signal to measure DCR in order to expand the application scope
of DCR measurement.
