Thyristor Semiconductor Products Page 59 Thyristor

2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/14/14 Teccor brand Thyristors AN1006 Procedure 5: V BO (Positive and Negative) To measure the V BO (Positive and Negative) parameter: 1. Set Left-Right Terminal Jack Selector to correspond with the location of the test fixture. 2. Set Variable Collector Supply Voltage to 55 V ( 65 V on 370) and apply voltage to the device under test (D.U.T.) using the Left Hand Selector Switch . The peak voltage at which current begins to flow is the V BO value. (Figure AN1006.19) 50 A 10 V PER V E R T DIV PER H O R I Z DIV PER S T E P ()k DIV 9m PER DIV V BO I BO +V BO +I BO Figure AN1006.19 (+)V BO = 35 V; (-)V BO = 36 V; ()I BO Procedure 6: I BO (Positive and Negative) To measure the I BO (Positive and Negative) parameter, at the V BO point, measure the amount of device current just before the device reaches the breakover point. The measured current at this point is the I BO value. Note: If I BO is less than 10 A, the current cannot readily be seen on curve tracer. Procedure 7: V BO (Voltage Breakover Symmetry) To measure the V BO (Voltage Breakover Symmetry) parameter: 1. Measure positive and negative V BO values per Procedure 5. 2. Subtract the absolute value of V BO (-) from V BO (+). The absolute value of the result is: V BO = [ I+V BO I - I -V BO I ] Procedure 8: V TM (Forward and Reverse) To test V TM , the Quadrac must be connected the same as when testing V BO , I BO , and V BO . To connect the Quadrac: 1. Connect MT1 to Emitter Terminal 2. Connect MT2 to Collector Terminal (C). 3. Connect Trigger Terminal to MT2 Terminal through a 10 resistor. Note the following: Due to the excessive amount of power that can be generated in this test, only parts with an I T(RMS) rating of 8 A or less should be tested on standard curve tracer. If testing devices above 8 A, a Tektronix model 176 high- current module is required. Kelvin fixture is not used, an error in measurement of V TM will result due to voltage drop in fixture. If a Kelvin fixture is not available, Figure AN1006.3 shows necessary information to wire a test fixture with Kelvin connections. To measure the V TM (Forward and Reverse) parameter: 1. Set Terminal Selector to Emitter Grounded-Open Base. 2. Set Max Peak Volts to 75 V. ( 80 V on 370) 3. Set Mode to Norm. 4. Set Horizontal knob to 0.5 V/DIV. 5. Set Power Dissipation to 220 watts ( 100 watts on a 577). 6. Set Vertical knob to a sufficient setting to allow the viewing of 1.4 times the I T(RMS) rating of the device I T(peak) on the CRT. Procedure 9: V TM(Forward) To measure the V TM (Forward) parameter: 1. Set Polarity to (+). 2. Set Left-Right Terminal Jack Selector to correspond with the location of the test fixture. 3. Increase Variable Collector Supply Voltage until current reaches rated I T(peak) , which is 1.4 times the I T(RMS) rating of the Triac under test. Note: Model 370 current is limited to 10 A. WARNING: Limit test time to 15 seconds maximum. 4. To measure V TM , follow along horizontal scale to the point where the trace crosses the I T(peak) value. This horizontal distance is the V TM 500 mV V E R T H O R I Z S T E P I PK V TM 1 A Figure AN1006.20 V TM (Forward) = 1.1 V at I PK = 5.6 A Thyristor and Rectifier Testing Using Curve Tracers (continued)

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