Electrical Parts, Controls, & Devices Part 4
Transducer | Thermostat | Thermistor | Light Dependent Resistor | Motor
Coil Solenoid | Buzzer | Fuse | Resistor | Heater | Lamp | Rheostat
Potentiometer| Timer | Transformer | Diode | Capacitor | Ground | Switches
Terms describing switch properties
Off position, offering infinite resistance to a circuit.
On position, offering zero resistance to a circuit.
Number of contact sets.
Number of conducting positions. (Single or double)
Number of conducting positions. (Three or more)
A switch that returns to its normal position when released.
Types of switches
On-Off Switch SPST:
(Single Pole, Single Throw)
An on-off switch allows current to flow only when it is in the closed or on position.
2-Way Switch SPDT:
(Single Pole Double Throw)
A 2-way switch directs the flow of current to one of two routes according to its position. Some SPDT switches have a central off position.
A relay is an electrically operated switch, commonly used in appliance control boards.
Pressure sensing switch:
This style of switch has a pressure sensing mechanism inside it, usually a diaphragm, which flexes as pressure increases and opens or closes a switch as the pressure reaches a specific level. These switches are commonly used in washing machines to sense the amount of water that has entered the washtub and prevent overflow.
Push to Make Switch:
A push to make switch allows current to flow when the switch is pressed.
Push to Break Switch:
This type of push switch is normally closed (on) it is open (off) only when the button is pressed.
Dual On-Off Switch DPST
(Double Pole Single Throw):
A dual on-off switch.Two switches that open and close at the same time.
Reversing Switch DPDT
(Double Pole Double Throw):
This switch can be used to change the direction of a motor.