SCR operating states: Forward blocking condition During the forward blocking state of an SCR (thyristor), what are the typical anode-cathode voltage and current levels, respectively?

Introduction / Context:
An SCR exhibits distinct operating states: forward blocking, forward conduction, and reverse blocking. Recognizing the voltage and current levels in each state is vital for protection and gating strategies.

Given Data / Assumptions:

• Anode positive with respect to cathode (forward bias).
• No gate trigger applied.
• Device is idealized to illustrate states (ignoring small leakage).

Concept / Approach:

In forward blocking, the SCR can withstand a high anode-to-cathode voltage but only a very small leakage current flows because the device has not been triggered into conduction.

Step-by-Step Solution:

Verification / Alternative check:

Device datasheets specify forward blocking voltage ratings and leakage currents in this state.

Why Other Options Are Wrong:

High current would imply turn-on. Low voltage/low current corresponds to an off device with no applied forward voltage, not forward blocking capability.

Common Pitfalls:

Confusing forward blocking with latching/holding current concepts that apply once turned on.

Final Answer:

high and low