Automatic
Does not require human intervention.
Auxiliary contacts
Control contacts that operate in unison with big power contacts.
Coil
Many turns of conductive wire that create an electromagnet when energized.
contacts
Two conductive points that allow or block current flow depending on whether they are closed or open.
electromechanical
A device that combines electrical and mechanical forces.
control circuit
Low power circuit using inputs and coils to determine outcomes in the big power circuit.
float switch
A switch that detects the height of liquid (or solid) inside of a tank.
Flow switch
A switch that detects the movement of fluid.
fuse
An overcurrent device with a fusible link that melts and opens the circuit.
solenoid
An electrical output device that converts electrical energy into linear mechanical force.
Jogging
The output is energized as long as the input device is activated.
Ladder Diagram
A diagram that shows the logic of a circuit using standard symbols.
Relay
A device that controls one electrical circuit by opening or closing contacts in another circuit (or part of circuit.)
Limit Switch
A mechanical input device that requires physical contact by an object with the switches actuator.
contactor
A control device that uses a small control current to energize or de-energize a larger load connected to it.
magnetic starter
An electrically operated switch (Contactor) that includes overload protection.
motor
A machine that converts electrical energy into mechanical energy by means of electrical induction.
Normally open and Normally Closed
Normally closed - Contacts have continuity (are closed) while at rest.
Normally open - Contacts do not have continuity (are open) while at rest.
Pressure Switch
An input device that detects a set amount of force and activates electrical contacts when the setpoint is reached.
Pushbutton
An electrical input device that a human needs to physically push the operator.
