TEST
DESCRIPTION
TRANSFORMER APPLICATION
REASON FOR TEST
CTY
Continuity
All
Properly installed fixture and part
R
DC Resistance
All
Properly installed fixture and part, correct wire used, integrity of terminations
LS
Inductance (Series circuit)
Most, but not usually line frequency
Checks primary turns, right grade of correctly assembled core material
LP
Inductance (Parallel circuit)
QL
Quality Factor
Checks right grade of correctly assembled core material, and for short turns
RLS
Equivalent Series Resistance
RLP
Equivalent Parallel Resistance
LSB
Inductance with Bias Current (Series Circuit)
Transformers that carry a significant dc bias current in normal operation
Check number of turns, right grade of correctly assembled core material
LPB
Inductance with Bias Current (Parallel Circuit)
LS
Inductance Match
SMP, audio and telecom
Checks matching between windings

LL

Leakage inductance
SMP, electronic ballasts
Check windings have been installed in the correct position relative to the core
LLO
C
Interwinding Capacitance
High frequency isolation
Check winding positioning and insulation thickness between windings.
C2
Capacitance Match
SMPS, but usually not line frequency
Check correct winding position on bobbin
TR
Turns Ratio and Phasing
Most, but usually not line frequency
Check windings have correct turns and polarity
TRL
Turns Ratio by Inductance
Check windings have correct turns
MAGI
Magnetising Current
Usually line frequency
Check primary turns and correct core material properly assembled
VOC
Open Current Voltage
Check secondary turns and phasing
IR
Insulation Resistance
All
Check winding isolation where safety is not involved
HPDC
Hi-Pot (DC)
All and especially those used for safety insulation
Check high voltage safety insulation
HPAC
Hi-Pot (AC)
WATT
Wattage
Line frequency
Right grade of correctly assembled core material
STRW
Stress Wattage
Line frequency and high frequency
Check integrity of interturn insulation, the nagnetic material and joints
SURG
Surge Stress Test
All, especially those with fine wire
Check interturn insulation, identify shorted turns
ILK
Leakage Current
Allisolating, especially medical
Check for leakage of line current to ground
GBAL
General Longitudinal Balance
Audio and telecom
Checks common mode rejection ratio
LBAL
Lonitudinal Balance
Audio and telecom
Checks common mode rejection ratio
ILOS
Insertion Loss
Audio and telecom
Checks power lost within the transformer
RLOS
Return Loss
Audio and telecom
Checks power lost within the transformer
Z
Impedance
Audio and telecom
Checks imedance at given frequency
ANGL
Impedance Phase Angle
Audio and telecom
Checks phase angle of complex impedance
PHAS
Interwinding Phase Angle
Measuring and signal
Checks phase of voltage between windings
TRIM
Trimming Adjustment
Transformers with variable / trimming components
To adjust transformer parameter to desired value during test
OUT
Output to User Port
Perform external switching as part of the test program
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