letter Cy

Contactor
Usually refers to a device with large contacts that close when
current is applied to its electromagnet; however, solid state
contactors are also available. Contactors are used to control the
power applied to motors, lights, or heating components.

Control Relay
Usually refers to a device with contacts that open and close
electromagnetically, but solid state control relays are also
available. Control relays typically handle smaller currents than
contactors, but are capable of switching more rapidly.


Coulomb
A unit of electrical charge moved in 1 second by a current of 1
ampere. This is equal to approximately 6.24 x 1018 electrons.

Coulomb’s Law
A law that states that charged objects attract or repel each
other with a force that is directly proportional to the product
of their charges and inversely proportional to the square of the
distance between them.