Automatic Production Testing Capabilities

  • Plitron uses automated programmable production line transformer testing.  Below is shown for capability only.
  • Test parameters are chosen and programmed per model number, and test reports and certificates of compliance are available on request.
  • Not all tests are routinely performed on all production transformers, unless added to the test spec by Plitron engineers or customer engineers.
  • Items shown as grey background indicate  mandatory testing.

Test Capabilities

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
Core within specs
MAGX MAGI (External Source)
VOC Open Circuit Voltage All other windings Correct secondary and primary taps 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.
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