In automatic control, which component adjusts the amount of turbo charging?

• A. Thottle linkage
• B. Electronic control unit
• C. Aneroid capsule
• D. Pressure regulator

Answer: (C)

Automatic boost control works by a pressure-sensing element that drives the wastegate to keep turbocharging at the desired level. The sensing element used here is an aneroid capsule, a sealed, gas-filled diaphragm that expands or contracts with boost pressure. When boost rises, the capsule moves and actuates the wastegate, releasing exhaust flow to limit further boost. This creates a self-regulating loop that automatically maintains the target turbocharger pressure.

The throttle linkage controls engine air entry but does not regulate turbo boost automatically. An electronic control unit can perform boost control in modern systems, but the question points to the traditional mechanical arrangement, where the aneroid capsule provides the automatic regulation. A pressure regulator sets or maintains a fixed pressure in a system, but it doesn’t directly modulate turbocharging in response to actual boost pressure.