(Week 9) Project, Electro-pneumatics and Design1

ELECTRO-PNEUMATICS

If voltage (V) is pressure (P), current (I) is mass flow rate (Q), what is resistance (R) in V = IR?

Resistance is viscosity ()!

A materials opposition to the flow of electric current; measured in ohms ()

To simplify

What is resistivity?

Which one actually kills you?

The danger of high voltage: high voltage means potential for large amounts of current through your body, which will injure or kill you.

Resistance opposes current. High resistance, good protection from shock.

Any V above 30 V can deliver potentially dangerous I.

Voltage or Current?

Introduction

Electro-pneumatic Combination of electrical and pneumatic system

Used when the process is repeating and setup cost is low

But

Maintenance troubleshooting is very complex

Structure circuit structure is messy when involving complex design

Components

Relay

On/Off switch

Components

Solenoid

Single valve solenoid Double valve solenoid

Symbols of Solenoid Valve

Pneumatic Circuit Symbol

Electrical Circuit Symbol

Y1

Development of Electro-pneumatic circuit

Circuit Design Structure

1.Identify sequence of movement

2.Divide sequence into groups

3.Identify limit switch status

4.Identify number of conductor line

( = number of group)

5.Identify number of reversing switch

(= number of group)

Circuit Design Structure - Example

Sequence : A+B+B-A-

Groups: K1 K2

Limit switch status:A1B1B0A0

Conductor Line: L1 L2

Reversing Switch: S1 S2

Basic Circuit

2 conductor lines

2 reversing switches

Start + A0 A+

A1 B+

B1 B-

B0 A-

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit

Electro-Pneumatic Circuit