Electro-Pneumatics

Basics

1. Electro-Pneumatic Circuits
Dr. S.N.Teli
Professor, Mechanical Engineering,
BharatiVidyapeethCollege of Engineering, NaviMumbai
Email: [email protected]
1
Dr. S. N.Teli

2. Electro-Pneumatic Circuit
2Dr. S. N. Teli
Que1: Explain about Relay.
Solution:Arelayisanelectricallyoperatedswitch.Itconsistsofasetofinput
terminalsforasingleormultiplecontrolsignals,andasetofoperatingcontact
terminals.Theswitchmayhaveanynumberofcontactsinmultiplecontactforms,
suchasmakecontacts,breakcontacts,orcombinationsthereof.
Thisisadrawingofade-energizedrelay,
Whennocurrentisflowinginthe
electromagnetcoilthearmatureispulledupby
thespringanditsCOMcontactconnectstothe
NCcontact.
This is a drawing of an energized relay. When a
voltage is applied to the electromagnet coil the
current flowing in the coil produces magnetic
energy in the iron core which pulls the armature
down. When the armature pulls down the COM
contactswitches from NC to NO.

3. Electro-Pneumatic Circuit
Fig: Direct Method
Solution:
3Dr. S. N. Teli
Que2: Draw electric circuit for AND logic using direct and indirect
method.+24V
0V
S1
3
4
S2
3
4
OutputB
1 +24V
0V
S1
3
4
S2
3
4
BR
A1
A2
R
3
4
1 2
2
Fig: In Direct Method
R-Relay

4. Electro-Pneumatic Circuit
Fig: Direct Method
Solution:
4Dr. S. N. Teli
Que3: Draw electric circuit for OR logic using direct and indirect
method.
Fig: In Direct Method+24V
0V
S1
3
4
S2
3
4
B
12 3 +24V
0V
S1
3
4
S2
3
4
R
A1
A2
Relay
R
3
4
B Output
12 3 4
4

5. Electro-Pneumatic Circuit
5Dr. S. N. Teli
Fig:Latching
Que4: Explain Latching logic Concept.
Solution:Asimpleexampleof
suchasituationisabulb,which
isstartedbypressingabutton
switch.Althoughtheswitch
contactsdonotremainclosed,it
isrequiredthatthebulb
continuetorununtilastop
buttonswitchispressed.
Thelatchingusedtostaythe
bulbrununtilthepushbuttonis
pressedagain.
START-NormallyOpen(NO)
Pushbutton;OFF-Normally
Closed(NC)Pushbutton.START
3
4
OFF
1
2
R
A1
A2
+24V
0V
R
3
4
R
3
4
START
R
R
STOP
R
Bu lb
Bu lb
Relay
1
2 3 4
6
7 8 9
8
9
8
9

6. Electro-Pneumatic Circuit
6Dr. S. N. Teli
Que5: Explain on-delay and off-delay timer.
Solution:
On-delayTimer:
Ex:WhentheS1switchisonthe
lubricantpump(LP)willstart
immediately,butgrindingmachine(GM)
willstartafterpresettime(say8Sec)of
timer.HereTisOn-delayTimer.
Off–DelayTimer:
Ex:Inacarwhenkey(Switch)ison
bothEngine(E)andfanareonattime.
Whenkeyisoff,theenginewilloff
immediatelybutfan(F)willoffafter
presettimeoftimer(Say15Sec).

7. Electro-Pneumatic Circuit
7Dr. S. N. Teli
Que6: if Switch S1 is on then Bulb A is on but Bulb B is on after 5 sec.
If Switch S1 is off, both Bulb should off. Draw a Electric logic ladder.S1
3
4
+24V
0V
R
3
4
R 5
A1
A2
Bulb A
Bulb B
On-delay timer
Switch
1 3
3
Fig:On-delay Timer
Solution:

8. Electro-Pneumatic Circuit
8Dr. S. N. Teli
Fig:Off-delay Timer
Solution:
Que7: If Switch S1 is on both bulbs on same time and if switch s1 is
off both bulb should off after 4 Second. Draw a Electric logic ladder.S1
3
4
+24V
0V
Bulb B
off-delay timer
Switch
R5
A1
A2
R
3
4
Bulb A
1 2
2

9. Electro-Pneumatic Circuit
9Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Que8: Draw Electro-pneumatic Circuit for A+A-4 2
5
1
3
A+ A-
S1 S2 S1
3
4
A+ A-
+24V
0V
S2
3
4
1 2
S1 and S2 are sensors; A+ and A-are Solenoids
Fig: Electric Ladder Logic Circuit

10. Electro-Pneumatic Circuit
10Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Que9: Draw Electro-pneumatic Circuit for A+A-using Relay. 4 2
5
1
3
A+ A-
S1 S2
S1 and S2 are sensors; A+ and A-are Solenoids; K1 and K2 are Relays
Fig: Electric Ladder Logic CircuitS1
3
4
A-
+24V
0V
K2
3
4
K1
3
4
K1
A1
A2
A+
S2
3
4
K2
A1
A2
1 2 34 5
2 5

11. Electro-Pneumatic Circuit
11Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution: 4 2
5
1
3
A+ A-
S1 S2 S1 and S2 are sensors; A+ and A-are Solenoids; K1 and K2 are Relays
Fig: Electric Ladder Logic Circuit
Que10: Draw Electro-Pneumatic Circuit for A+ A-using latching Circuit.S1
3
4
+24V
K1
A1
A2
0V
K1
3
4
Relay
S2
1
2
S1
3
4
A+
S2
3
4
S1
1
2
K2
A1
A2
K2
3
4
A-
K2
3
4
1 2 3 4 5
6
2 5
6

12. Electro-Pneumatic Circuit
12Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution: S1& S2 are sensors; A+& A-are Solenoids; T1&T2 are on-delay timers
Fig: Electric Ladder Logic Circuit
Que11:Draw an Electro-Pneumatic Cktfor(Delay)A+(Delay)A-.+24V
0V
S1
3
4
T1 5
A1
A2
On-delay Timer
T1
3
4
A+
S2
3
4
T2 10
A1
A2
T2
3
4
A-
On-delay Timer
1 2 3 4
2 4 4 2
5
1
3
A+ A-
S1 S2

13. Electro-Pneumatic Circuit
13Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution: S1& S2 are sensors; A+& A-are Solenoids; T is on-delay timer.
Fig: Electric Ladder Logic Circuit
Que12: Draw Electro-Pneumatic circuit for A+ (delay) for multi-cycle. 4 2
5
1
3
A+
S1 S2 +24V
0V
S1
3
4
R
A1
A2
S2
3
4
T 5
A1
A2
R
3
4
T
1
2
R
3
4
A+
12 34 5 6 7
4
7
2

14. Electro-Pneumatic Circuit
14Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Fig: Electric Ladder Logic Circuit
Que13:Draw the Electro-pneumatic circuit for A+B+(AB)-4 2
5
1
3
Y1 Y2
4 2
5
1
3
Y3 Y4
S1 S2
S3 S4 +24V
0V
S1
3
4
Y1
S4
3
4
Y2Y3
S2
3
4
Y4
12 3 4 5

15. Electro-Pneumatic Circuit
15Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Fig: Electric Ladder Logic Circuit
Que14: Design Electro-Pneumatic Circuit for A+B+B-A-4 2
5
1
3
Y1 Y2
4 2
5
1
3
Y3 Y4
S1 S2
S3 S4 S1
3
4
K1
A1
A2
K1
3
4
S4
1
2
K1
3
4
Y1
S2
3
4
K1
3
4
Y3
S4
3
4
K2
A1
A2
K2
3
4
S1
1
2
K2
3
4
Y4
S3
3
4
K2
3
4
Y2
+24V
0V
1 2 3 4 5 6 7 8
2
3
4
6
7
8

16. Electro-Pneumatic Circuit
16Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Fig: Electric Ladder LogicCircuit
Que15: Design Electro-Pneumatic Circuit for A+A-B+B-4 2
5
1
3
Y1 Y2
4 2
5
1
3
Y3 Y4
S1 S2
S3 S4 +24V
0V
S1
3
4
S3
3
4
K
1
2
Y1
S2
3
4
K
A1
A2
K
3
4
S4
1
2
S3
3
4
S1
3
4
K
3
4
Y3
S4
3
4
Y4
S2
3
4
Y2
12 3 4 5 6 7
4
6
2

17. Electro-Pneumatic Circuit
17Dr. S. N. Teli
Fig: Pneumatic Circuit
Solution:
Fig: Electric Ladder LogicCircuit
Que16: Design Electro-Pneumatic Circuit for A-B+(delay)B-A+4 2
5
1
3
Y1 Y2
4 2
5
1
3
Y3 Y4
S1 S2
S3 S4 +24V
0V
S2
3
4
K1
A1
A2
K1
3
4
S4
1
2
K1
3
4
S1
3
4
S3
3
4
Y3
S4
3
4
K1
3
4
Y2
K2
A1
A2
S2
1
2
K2
3
4
K2
3
4
Y4
S1
3
4
Y1
K1
1
2
S3
3
4
S4
3
4
T 5
A1
A2
T
3
4
1 2 3 4 56 78 9 10 11
3
4
6
1 11 10
11

18. Electro-Pneumatic Circuit
18Dr. S. N. Teli
Solution:
Que17: Design Electro-Pneumatic Circuit for (AB)+A-C+C-B-4 2
5
1
3
Y1 Y2
S1 S2
4 2
5
1
3
Y3 Y4
S3 S4
4 2
5
1
3
Y5 Y6
S5 S6 +24V
0V
Y1
S3
3
4
Y3
S2
3
4
Y2
S5
3
4
Y5
S1
3
4
S4
3
4
S6
3
4
K
3
4
K
A1
A2
S2
1
2
S3
3
4
S4
1
2
S1
3
4
K
3
4
Y6
S5
3
4
K
3
4
Y4
1 2 3 4 5 6 7 8
6
7
8

19. Electro-Pneumatic Circuit
19Dr. S. N. Teli
Solution:
Que18: Draw an Electro-Pneumatic Circuit for 4(A+A-) delay for
multi-cycle.4 2
5
1
3
A+ A-
S1 S2 +24V
0V
S1
3
4
A+
C
1
2
S2
3
4
C 5
A1
A2
R1
R2
T
3
4
S2
3
4
A-
C
3
4
T 10
A1
A2
1 23 4 5 6
61 4
Fig: Pneumatic Circuit Fig: Electric Ladder LogicCircuit

20. Electro-Pneumatic Circuit
20Dr. S. N. Teli
Solution:
Que19: Draw an Electro-Pneumatic Circuit for A+B+C+C-B-A-4 2
5
1
3
Y1 Y2
4 2
5
1
3
Y3 Y4
4 2
5
1
3
Y5 Y6
S1 S2 S3 S4
S5 S6 +24V
0V
S1
3
4
K1
A1
A2
K1
3
4
Y1
K1
3
4
S4
1
2
S2
3
4
K1
3
4
K3
A1
A2
Y3
K3
3
4
S6
1
2
S4
3
4
K3
3
4
K5
A1
A2
S6
3
4
K5
3
4
S6
1
2
K6
A1
A2
K6
3
4
S3
1
2
K3
3
4
K6
3
4
Y6
S5
3
4
K6
3
4
K5
3
4
Y5
K3
3
4
S2
3
4
S3
3
4
Y2
K4
A1
A2
K4
3
4
Y4
K4
3
4
S1
3
4
1 2 34 56 7 8 9 1011 12 1314 15 16 17 18 19 20
7
8
9
12
11
12
15
16
17
18
19

21. Dr. S.N.Teli
21