ELECTRO – PNEUMATIC Il Amalan Kejuruteraan Mekanikal II BDA 1811 • • • •
Prepared by: Saliana binti Sanusi
[email protected] Tel: 013-3878446
Department of Manufacturing & Industrial Engineering, Faculty of Mechanical & Manufacturing Engineering
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… • Safety in handling high voltage application
1 phase
3 phase
• Many contactors, so many OUTPUTS can be applied
relay
Some examples…. Many contactors
Power Relay
Tripping relay
how to connect???? RELAY
CONTACTOR