SCR terminal count (gate connections) How many gate terminals does a standard SCR (silicon controlled rectifier) have?

Introduction / Context:
Terminal identification is basic but critical. An SCR is a three-terminal device: anode, cathode, and a single gate used to initiate conduction at the chosen firing angle.

Given Data / Assumptions:

• Standard SCR structure (not SCS or TRIAC).
• Single gate that requires a trigger current pulse.

Concept / Approach:

To turn on an SCR in the forward-blocking state, a suitable gate current pulse is injected between gate and cathode. Only one gate terminal exists, and there is no additional control terminal like in SCS devices.

Step-by-Step Solution:

Verification / Alternative check:

All SCR datasheets and symbols show a single gate lead. Multi-gate thyristor variants are different devices.

Why Other Options Are Wrong:

Options with 3, 4, or 6 gates are not applicable. A gate-less device would be a diode or Shockley diode, not an SCR.

Common Pitfalls:

Confusing SCR with TRIAC (still one gate) or SCS (two gates), or mixing total leads with number of gates.

Final Answer:

1