Thyristor Semiconductor Products Page 51 Thyristor

2014 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 12/14/14 Teccor brand Thyristors AN1006 500 mV V E R T H O R I Z S T E P I T V FM 2 A Figure AN1006.4 V FM = 1 V at I PK = 20 A SCRs SCRs are half-wave unidirectional rectifiers turned on when current is supplied to the gate terminal. If the current supplied to the gate is to be in the range of 12 A and 500 between 1 mA and 50 mA, then a non-sensitive SCR is required. To connect the rectifier: 1. Connect Anode to Collector Terminal (C). 2. Connect Cathode to Emitter Terminal (E). Note: When sensitive SCRs are being tested, a 1 k resistor must be connected between the gate and the cathode, except when testing I GT . To begin testing, perform the following procedures. Procedure 1:V DRM / V RRM / I DRM / I RRM To measure the V DRM / V RRM / I DRM , and I RRM parameter: 1. Set Variable Collector Supply Voltage Range to appropriate Max Peak Volts for device under test. (Value selected should be equal to or greater than the device's V DRM rating.) 2. Set Horizontal knob to sufficient scale to allow viewing of trace at the required voltage level. (The 100 V/DIV scale should be used for testing devices having a V DRM value of 600 V or greater; the 50 V/DIV scale for testing parts rated from 300 V to 500 V, and so on.) 3. Set Mode to Leakage . 4. Set Polarity to (+). 5. Set Power Dissipation to 0.5 W. ( 0.4 W on 370) 6. Set Terminal Selector to Emitter Grounded-Open Base . 7. Set Vertical knob to approximately ten times the maximum leakage current (I DRM , I RRM ) specified for the device. (For sensitive SCRs, set to 50 A. ) Note: The CRT screen readout should show 1% of the maximum leakage current if the vertical scale is divided by 1,000 when leakage current mode is used. Procedure 2:V DRM / I DRM To measure the V DRM and I DRM parameter: 1. Set Left-Right Terminal Jack Selector to correspond with location of test fixture. 2. Set Variable Collector Supply Voltage to the rated V DRM of the device and observe the dot on CRT. Read across horizontally from the dot to the vertical current scale. This measured value is the leakage current. (Figure AN1006.5) WARNING: Do NOT exceed V DRM /V RRM rating of SCRs, Triacs, or Quadracs. These devices can be damaged. 100 nA 100 V E R T H O R I Z S T E P V DRM I DRM Figure AN1006.5 I DRM = 350 nA at V DRM = 600 V Procedure 3: V RRM / I RRM To measure the V RRM and I RRM parameter: 1. Set Polarity to (-). 2. Repeat Steps 1 and 2 (V DRM , I DRM ) except substitute V RRM value for V DRM . (Figure AN1006.6) 100 nA 100 V E R T H O R I Z S T E P V RRM I RRM Figure AN1006.6 I RRM = 340 nA at V RRM = 600 V Thyristor and Rectifier Testing Using Curve Tracers (continued)

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