Thyristor Semiconductor Products Page 63 Thyristor

2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/14/14 Teccor brand Thyristors AN1006 Procedure 2: V BO To measure the V BO 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 for 370) and apply voltage to device under test (D.U.T.), using Left-Right-Selector Switch . The peak voltage at which current begins to flow is the V BO AN1006.26) 50 A 10 V E R T H O R I Z S T E P +V BO +I BO I BO V BO Figure AN1006.26 (+)V BO = 35 V; (-)V BO = 36 V; ()I BO I BO Procedure 3: I BO To measure the I BO parameter, at the V BO point, measure the amount of device current just before the device reaches the breakover mode. 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 the curve tracer. Procedure 4: V BO(Voltage Breakover Symmetry) To measure the V BO (Voltage Breakover Symmetry) parameter: 1. Measure positive and negative values of V BO as shown in Figure AN1006.26. 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 ] Model 370 Curve Tracer Procedure Notes Because the curve tracer procedures in this application note are written for the Tektronix model 576 curve tracer, certain settings must be adjusted when using model 370. Variable Collector Supply Voltage Range and Power Dissipation controls have different scales than model 576. The following table shows the guidelines for setting Power Dissipation when using model 370. (Figure AN1006.27) Model 576 Model 370 If power dissipation is 0.1 W, set at 0.08 W. If power dissipation is 0.5 W, set at 0.4 W. If power dissipation is 2.2 W, set at 2 W. If power dissipation is 10 W, set at 10 W. If power dissipation is 50 W, set at 50 W. If power dissipation is 220 W, set at 220 W. Although the maximum power setting on the model 370 curve tracer is 200 W, the maximum collector voltage available is only 400 V at 220 W. The following table shows the guidelines for adapting Collector Supply Voltage Range settings for model 370 curve tracer procedures: Model 576 Model 370 If voltage range is 15 V set at 16 V. If voltage range is 75 V set at 80 V. If voltage range is 350 V set at 400 V. If voltage range is 1500 V set at 2000 V The following table shows the guidelines for adapting terminal selector knob settings for model 370 curve tracer procedures: Model 576 Model 370 If Step generator (base) is emitter grounded then Base Step generator is emitter common. If Emitter grounded is open base then Base open is emitter common. Thyristor and Rectifier Testing Using Curve Tracers (continued)

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