6. Contoso
S u i t e s
6
▪ Relay
▪ It is an electromagnetic switch which use magnetic field to open and Close its contacts
❑ coil
❑ Auxiliary contacts
Electronics :-
9. Contoso
S u i t e s
9
▪ Relay
▪ moving parts in relay which is used To connect or disconnect our circuit
1- Cannot afford main loads
2- used In control circuits
❑ Auxiliary contacts:
▪ Relay may have more than one contact
▪ Max current 20 Amp
▪ Latching relay
❑ Coil:
▪ Is an electrical conductor, wire in the shape as Coil, when current is
passed through the wire of The coil it generates a magnetic field it has
standard Voltage ranges “5, 7, 12, 24…” DC “12, 24, 110, 220…” AC
Electronics :-
11. Contoso
S u i t e s
11
▪ Contactor
❑ Coil
❑ Auxiliary contacts
❑ Main contacts
❑ Parts in contactor used To connect and disconnect our loads
▪ DC powered coils, they generate a constant magnetic field that guarantees an appropriate
closing of the contacts
▪ AC powered coils generate sinusoidal magnetic fields which produce a force
that drops to zero twice each cycle (50/60 Hz). This creates an undesired
chatter or pulsation of the contacts. This harmful effect can be cancelled by
using a shading ring placed in the contactor core
▪ It is an electromagnetic switch which use magnetic field to open and Close its contacts
Electronics :-
14. Contoso
S u i t e s
14
▪ Contactor
▪ Power of your load or its maximum current
▪ Range of voltage of control circuit “to select coil”
▪ Number of auxiliary contacts and its type “NO, NC”
❑ There are some important information that you must know.
Electronics :-
15. Contoso
S u i t e s
15
Electronics :-
▪ Solid-state relay
A solid-state relay (SSR) is an electronic switching device that switches on or off when a small
external voltage is applied across its control terminals. SSRs consist of a sensor which responds
to an appropriate input (control signal), a solid-state electronic switching device which switches
power to the load circuitry.
16. Contoso
S u i t e s
16
Electronics :-
▪ Solid-state relay
17. Contoso
S u i t e s
17
Electronics :-
▪ Semiconductors
A semiconductor material has an electrical conductivity value falling between that of a conductor,
such as copper, and an insulator, such as glass. Their resistance decreases as their temperature
increases.