ELECTRO – PNEUMATIC IlELECTRO – PNEUMATIC Il

Amalan Kejuruteraan Mekanikal IIAmalan Kejuruteraan Mekanikal II

BDA 1811BDA 1811

Department of Manufacturing & Industrial Engineering,

Faculty of Mechanical & Manufacturing Engineering

Prepared by:

Saliana binti Sanusi

saliana@uthm.edu.my

Tel: 013-3878446

Learning Outcomes:

After finish this task, students are able to:

• Explain holding circuit concept correctly• Write latching definition• Use latching technique in designing

electro-pneumatic circuit• Recognize and explain what is relay, its

construction and how it works

Holding Circuit

• Holding circuit means the electricity of a circuit is remain activate although the switch is turned OFF until the reset switch is turn ON.

This is how they work…

Remain ON

We also call this technique as “Latching” or “memory circuit”

This condition occur is because of the existing an electro-mechanical device called:

“RELAY”

WHAT IS RELAY?

• An electrical switch that can be actuated indirectly by another switch

(Automation, Production Systems and Conputer Integrated Manufacturing, Mikell P. Groover, 1987 – Prentice Hall Inc. pg 650)

A relay is a solenoid set up to actuate switch contacts when its coil is energized

Relay = solenoid + contactor

• Relay is used as an auto, indirect switch which operated when electric current flows through a “solenoid”

• Together with this solenoid in a relay is a contactor

Relay Characteristics

• Low maintenance

• Able to switch a number of independent circuit path

• Easily adaptable to various operating voltages

• High operating speed- short switching times

how does relay been constructed?

Relay advantages…1. Safety in handling high voltage application

1 phase 3 phase

2. Many contactors, so many OUTPUTS can be applied

relay

Some examples….

Many contactors

Power Relay

Tripping relay

how to connect????

RELAY

CONTACTOR