The speed control on this type of mixer results from the interaction of mechanical action and electronic control. Two variations of electrical control can be found but each uses the same mechanical action.
Two small spring steel plates are fixed to the cooling fan on the lower end of the armature shaft. They are slightly bowed and joined at either end by a small weight. Only the top plate is secured to the fan and shaft. When the motor rotates, the weights on each end of the joined plates are forced outwards by centrifugal force. As they are formed in a bowed configuration and joined at either end, the outward movement of the weights causes the lower plate to be forced downwards. The degree of movement is proportional to the rotational speed of the armature. This movement is used to actuate a switch on the speed control panel. Read the rest of this entry »
