| Test |
Description |
Main Application |
Winding Tested |
Reason for Test |
| CTY |
Continuity |
All transformers |
|
Properly installed fixture |
| R |
DC Resistance |
All transformers |
All windings |
Properly installed fixture
Correct wire used Integrity of terminations |
| LS |
Inductance
(Series circuit) |
Most transformers
But usually not line frequency transformers |
One winding usually the primary |
Correct primary turns
Right grade of core material Core correctly assembled |
| LP |
Inductance
(Parallel circuit) |
| QL |
Quality Factor |
Right grade of core material
Core correctly assembled Check for shorted turns |
| RLS |
Equivalent Series Resistance |
| RLP |
Equivalent Parallel Resistance |
| D |
Dissipation Factor |
| LL |
Leakage Inductance |
SMPS transformers Communication transformers
Others as applicable |
Selected windings |
Check windings have been installed in the correct position relative to the core |
| LLO |
| C |
Interwinding Capacitance |
High frequency transformers
Isolating transformers |
|
Check winding positioning Check insulation thickness between windings |
| TR |
Turns Ratio and Phasing |
Most transformers, but usually not line frequency transformers |
All windings |
Check windings have correct turns and phasing |
| TRL |
Turns Ratio by Inductance |
As with Turns Ratio but used where there is poor flux linkage between windings. |
All windings |
Check windings have correct turns and phasing |
| MAGI |
Magnetising Current |
Usually line frequency transformers |
One winding, usually the primary |
Correct primary turns
Correct core material properly assembled |
| MAGX |
MAGI (External Source) |
| VOC |
Open Circuit Voltage |
All other windings |
Correct secondary turns
Correct phasing |
| VOCX |
VOCX (External Source) |
| LVOC |
Low Voltage
Open Circuit |
| IR |
Insulation Resistance |
All transformers |
Between selected windings |
Winding isolation check where safety is not involved |
| HPDC |
Hi-Pot (DC) |
All transformers especially those used for safety insulation |
Between selected windings usually primary to secondary, screens and core |
High voltage safety insulation |
| HPAC |
Hi-Pot (AC) |
| LSB |
Inductance with Bias Current (Series Circuit) |
Transformers for use in applications where passing significant (dc) bias current is part of the normal operation |
One winding |
Correct number of turns
Right grade of core material Core correctly assembled |
| LPB |
Inductance with Bias Current (Parallel Circuit) |
| WATT |
Wattage |
50Hz Iron core transformers |
One winding |
Correct core material
Properly assembled |
| WATX |
Wattage (External Source) |
50Hz Iron core transformers |
One winding |
Correct core material
Properly assembled |
| SURG |
Surge Stress Test |
All transformers, especially those using fine wire |
Selected windings |
To identify shorted turns |
| TRIM |
Trimming Adjustment |
Transformers with variable / trimmable components |
|
To adjust transformer to give specific measured values |
| OUT |
Output To User Port |
|
|
Allows the AT to perform external switching as part of the test program. |
| R2 |
DC Resistance Match |
SMPS, audio & telecom |
All windings |
Checks matching between windings |
| L2 |
Inductance Match |
SMPS, audio & telecom transformers |
All windings |
Checks matching between windings |
| C2 |
Capacitance Match |
SMPS, audio & telecom transformers |
All Windings |
Checks correct winding position on bobbin |
| GBAL |
General Longitudinal Balance |
Audio & telecom transformers |
Selected Windings |
Checks common mode rejection ratio |
| LBAL |
Longitudinal Balance |
Audio & telecom transformers |
Selected Windings |
Checks common mode rejection ratio |
| ILOS |
Insertion Loss |
Audio & telecom transformers |
Selected Windings |
Checks losses within the transformer |
| RESP |
Frequency Response |
Audio & telecom transformers |
Selected Windings |
Checks losses over a range of frequencies |
| RLOS |
Return Loss |
Audio & telecom transformers |
Selected Windings |
Checks losses returned by a transformer |
| Z |
Impedance |
Audio & telecom transformers |
Selected Windings |
Checks impedance at a given frequency |
| ZB |
Impedance + bias |
Audio & telecom transformers |
Selected Windings |
Checks impedance at a given frequency |
| STRW |
Stress Wattage |
Line frequency & High Frequency Transformers |
One Winding (Usually the primary) |
Checks integrity of inter-turn insulation, the magnetic material and joints |
| STRX |
STRW (External Source) |
|
|
|
| ANGL |
Impedance Phase Angle |
Audio & telecom transformers |
Selected Windings |
Finds phase shift between Voltage and Current on a winding. |
| PHAS |
Interwinding Phase Test |
Audio & telecom transformers |
Selected Windings |
Measures phase shift between a pair of windings |
| ILK |
Leakage Current Test |
Medical applications |
Between Primary and Secondary Windings |
Checks for a common mode current due to capacitance |
|
LSBX* |
Inductance with External Bias (Series Circuit) |
Wound components that usually carry a significant DC Bias current in normal operation. |
Selected Windings |
Checks number of turns, right grade of correctly assembled core material, where bias current is greater than LSB test can handle.
|
|
LPBX* |
Inductance with External Bias (Parallel Circuit) |
Wound components that usually carry a significant DC Bias current in normal operation. |
Select Windings |
Checks number of turns, right grade of correctly assembled core material, where bias current is greater than LPB test can handle. |
|
ZBX* |
Impedance with External Bias |
Audio & Telecom |
Selected Windings |
Checks impedance at a given frequency, while applying a greater bias current than is possible with ZB test. |
| ACRT |
Hi-Pot Ramp (AC) |
All transformers especially those used for safety insulation |
Between selected windings usually primary to secondary, screens and core |
High voltage safety insulation |
| DCRT |
Hi-Pot Ramp (AC) |
All transformers especially those used for safety insulation |
Between selected windings usually primary to secondary, screens and core |
High voltage safety insulation |