Peak Forward Blocking Current - IDRM What It Is: With no gate signal applied, peak forward blocking current is the maximum anode current that flows with the SCR in the blocked (Off) state. On the curve tracer, the Collector Supply drives the anode and the gate is held open. What The Display Shows: The display shows anode voltage on the horizontal axis, and the resulting anode current on the vertical axis.  The specification is met when with the specified anode voltage applied, anode current is less than or equal to the specified maximum. How To Do It: 1. Set controls: A: Max Peak Volts to the lowest setting above the specified VDRM B: Max Peak Power Watts to the lowest setting that satisfies (IDRM x VDRM) C: Horizontal Volts/Div to display VDRM between the 5th and 10th horizontal divisions D: Vertical Current/Div to display the IDRM between the 5th and 10th vertical divisions E: Collector Supply Polarity to +DC F: Configuration to (Base/Open, Emitter/Common) G: Variable Collector Supply to minimum % (full ccw) H: DotCursor ON 2. Apply power to the SCR: A: Position the Left/Right switch as appropriate B: Slowly increase the Variable Collector Supply % until the specified VDRM   is reached 3. Compare to data sheet specifications: Check that at the specified VDRM, IDRM is less than or equal to the specified maximum