What is a centrifugal switch?
The centrifugal switch is a device designed to open or close a set of electrical contacts when the machine that is connected to achieve a predetermined rotary speed. These devices use a phenomenon known as a centrifugal force to achieve this switching action. The most common use of centrifugal switches are cut -outs of starters on petrol engines and start of disconnecting windings in electric motors divided phase. The centrifugal force is a product of rotary movement and requires half of the centrifugal switch to turn along with the crankshaft or rotor and the other to be static.
If a bucket of water quickly rotates in an arc by 360 degrees, none of the water will spill from the bucket if the rotation is maintained. If a heavy ball rotates at the end of the rope in the same way, the ball rises until it is at the center of the rotation. A quick turn car will also tend to drift towards the outside of the corner. All these effects are the result of the centrifugal force that dictates,that inertia in conjunction with rotation will always force a rotating object from the center of rotation. This effect forms the core of the centrifugal switch.
The centrifugal switch usually consists of two parts. The first is a spring -charged spring spring connected to the controller and the electric switchboard. This assembly is mounted on the engine crankshaft or on the electric motor rotor. The second is a static electric switch mounted in direct contact with a rotating switching plate when the engine or engine is stationary. These two switching plates represent a closed or active electrical circuit while the machine does not turn.
When the engine or engine starts to rotate, both switching plates keep the electrical contact until the machine reaches the pre -set rotation. At this point, the centrifugal force begins to tag it is from the center of rotation and causes the driver to move the swivel switch from its static counterpart to interruptl circuit. Once the engine or engine is turned off and stops, the springs pull the weight back to its resting position to restore the connection.
The centrifugal switch is most often used to power the initial windings of electric motors with a split phase. The switch will maintain the connection until the engine reaches approximately 75% of its operating speed and then switch the starter power supply. This allows the engine to work with its running winding itself. The centrifugal switches are also used in gasoline engines for automatic starts, where they keep the electric starter of rotation until the engine reaches the pre -set speed.