Thyristor Semiconductor Products Page 60 Thyristor

2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/14/14 Teccor brand Thyristors AN1006 Procedure 10: V TM(Reverse) To measure the V TM (Reverse) 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) . 4. Measure V TM(Reverse) the same as in Procedure 8. (Read measurements from upper right corner of screen). Procedure 11: I H(Forward and Reverse) For these steps, it is again necessary to connect the Trigger to MT2 through a 10 resistor. The other connections remain the same. To measure the I H (Forward and Reverse) parameter: 1. Set Power Dissipation to 50 W. 2. Set Max Peak Volts to 75 V. ( 80 V on 370) 3. Set Mode to DC. 4. Set Horizontal knob to 5 V/DIV. 5. Set Vertical knob to approximately 10% of the maximum I H specified. Note: Due to large variations of holding current values, the scale may have to be adjusted to observe holding current. 6. Set Terminal Selector to Emitter Grounded-Open Base . Procedure 12: I H(Forward) To measure the I H (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 to maximum position ( 100 ). Note: Depending on the vertical scale being used, the dot may disappear completely from the screen. 4. Decrease Variable Collector Supply Voltage to the point where the line on the CRT changes to a dot. The position of the beginning point of the line, just before the line changes to a dot, represents the I H value. (Figure AN1006.21) 5 mA 5 V PER V E R T DIV PER H O R I Z DIV PER S T E P ()k DIV 9m PER DIV I H Figure AN1006.21 I H (Forward) = 18 mA Procedure 13: I H(Reverse) To measure the I H (Reverse) parameter: 1. Set Polarity to (-). 2. Continue testing per Procedure 12 for measuring I H (Reverse) . SIDACs The SIDAC is a bidirectional voltage-triggered switch. Upon application of a voltage exceeding the SIDAC breakover voltage point, the SIDAC switches on through a negative resistance region (similar to a DIAC) to a low on-state voltage. Conduction continues until current is interrupted or drops below minimum required holding current. To connect the SIDAC: 1. Connect MT1 to the Emitter Terminal 2. Connect MT2 to the Collector Terminal (C). To begin testing, perform the following procedures. Procedure 1: (+) V DRM , (+)I DRM , (-)V DRM , (-)I DRM Note: The (+) and (-) symbols are used to designate the polarity of MT2 with reference to MT1. To measure the (+)V DRM , (+)I DRM , (-)V DRM , and (-)I DRM parameter: 1. Set Variable Collector Supply Voltage Range to 1500 Max Peak Volts. 2. Set Horizontal knob to 50 V/DIV. 3. Set Mode to Leakage. 4. Set Polarity to (+). 5. Set Power Dissipation to 2.2 W. ( 2 W on 370) 6. Set Terminal Selector to Emitter Grounded-Open Base. 7. Set Vertical knob to 50 A/DIV . (Due to leakage mode, the CRT readout will show 50 nA.) Thyristor and Rectifier Testing Using Curve Tracers (continued)

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