Final answer:
Automatic expansion valves operate similarly to power brakes and those in bulldozers, with a motorized pump doing most of the work in the system.
Step-by-step explanation:
The operating concept of automatic expansion valves is similar to that of power brakes and those in bulldozers that have a motorized pump doing most of the work in the system. In power brakes, a motorized pump assists in applying force to the brake system, enabling easy and efficient braking. Similarly, in bulldozers, a motorized pump is used to control the hydraulic system for efficient operation.