Relays

An electronic powered switch is called a......................

A relay picture:

• 
• 
• 
• 

A type of a relay:

• Normally open

• Latching relay

• Normally closed.

• Preset relay

Draw a single pole double through relay symbol.

Draw a double pole single through relay symbol.

NO stands for

• Normally ON contact

• Normally Ord contact

• Normally Off contact

• Normally Open contact

A characteristic of a relay:

• Offers high electrical isolation

• Switching is fast

• Has no hazardous conditions

• Uses very low current

Two factors to consider when choosing a relay:

• Coil voltage

• Reed relay

• Mercury wetted relay

• Rating of a relay

Relays that used for machine tools are called:

During an ON state of a relay the......................of a relay open/s.