The first category, then there is no centrifugal switch […]
The first category, then there is no centrifugal switch, a single capacitor phase-shifting, such as fans, which are usually used on small motors
The second category, there is a centrifugal switch, single-phase capacitor phase-activated, such as some fans and other equipment, but for various reasons, this motor seems to be less and less. But in some special places, it does exist.
The third category, that is, there is a centrifugal switch, dual-capacitor dual-phase shift, the most common in many places, such as air compressors, cutting machines, bench drill and other places. You can go to some cutting machines and air compressors (but now seems to be a lot of cylinders in order to reduce the cost of the second motor or more, while more than two-cylinder, almost all of this motor had) look, the motor has 2 metal boxes, cylindrical, each is installed a capacitor, and one of them is to start the capacitor (large capacity) and the other is running capacitance (small capacity).
Experience Summary: This is probably the case, the centrifugal switch in the second category, only to connect and disconnect the auxiliary winding (also known as the start winding) and the connection between the capacitor and the circuit, and in the third type of motor, Control the use of secondary winding capacitor is large or small capacity.