汽车控制系统中螺线管电流的测量 By Scott Beversdorf Chuck Whiting Solenoids in Automotive Control Applications A solenoid is a linear motor with a fixed range of travel. Solenoids may be designed for simple on-off applications, acting much like relays. For example, they are used this way in starters and door locks. On the other hand, a linear, or proportional, solenoid is one whose position can be controlled in a precise manner. They are used to operate pistons and valves for accurate control of fluid pressure or flow in applications such as transmissions and fuel injection.