3-14
marked C, NO, and NC. These letters stand for common, normally open, and normally closed. The
common terminal is connected to the normally closed terminal until the plunger is depressed. When the
plunger is depressed, the spring will "snap" into the momentary position and the common terminal will be
connected to the normally open terminal. As soon as the plunger is released, the spring will "snap" back
to the original condition.
This basic accurate snap-acting switch is used in many applications as an automatic switch. Several
different methods are used to actuate this type of switch. Some of the more common actuators and their
uses are shown in figure 3-14.
Figure 3-14.—Common actuators and their uses for accurate snap-acting switches.
Q10. What classification of a switch is used when you describe it as a rocker switch?
Q11. In describing a switch by the number of positions of the actuator, what are the two possible
configurations for a single-pole, double-throw switch?
Q12. What type of switch should be used to control a circuit that requires a temporary actuation
signal?
Q13. What type of switch is used if it is necessary to guard against a circuit being accidentally turned
on or off?
Q14. What is the common name used for an accurate snap-acting switch?
