This document contains the detailed note on how to reduce the block diagram with some defined steps.It also contains an example for the better conceptualization of this topic.

1. RULES FOR
BLOCK DIAGRAM
REDUCTION
by
Milap Bhanderi
Subject: Digital Electronics
Ins+tute: Silver Oak College of Engineering and Technology.
Copyright © 2017 by Milap Bhanderi

2. 1. Blocks in Series.
2. Blocks in Parallel.
3. Eliminate feedback loop.
4. AssociaIve rule for summing point.
5. ShiLing a summing point before a block.
6. ShiLing a summing point aLer a block.
7. ShiLing take off point before a block.
8. ShiLing take off point aLer a block.
9. ShiLing a take off point aLer a summing point.
10. ShiLing a take off point before a summing point.
Copyright © 2017 by Milap Bhanderi

3. 2G1G 21GG
1. Combining blocks in series
1G
2G
21 GG +
2. Combining blocks in parallel
Copyright © 2017 by Milap Bhanderi

4. 3. Moving a summing point behind
a block
G G
G
4. Moving a summing point ahead of
a block
G G
G
1
Copyright © 2017 by Milap Bhanderi

5. 6. Moving a takeoff point ahead of
a block
G G
G G
G
1
G
5. Moving a takeoff point behind
a block
Copyright © 2017 by Milap Bhanderi

6. 7. Eliminating a feedback loop
G
H
GH
G
∓1
8. Swap with two neighboring
summing points
A B AB
G
1=H
G
G
∓1
Copyright © 2017 by Milap Bhanderi

7. 9. Shifting a takeoff point after
a summing point
Y
±
Z
R C
Y
±
Z
R C
Ø C(S)=R ± Y
Z=R
Ø C(S)=R ± Y
Z=R ± Y
Copyright © 2017 by Milap Bhanderi

8. 10. Shifting a takeoff point before
a summing point
Y
±
Z
R C
Ø C(S)=R ± Y
Z=R ± Y
Ø C(S)=R ± Y
Z=R ± Y
Y
±
R C
Z Copyright © 2017 by Milap Bhanderi

9. R
_ +
_
+ 1G 2G 3G
1H
2H
+
+
C
Copyright © 2017 by Milap Bhanderi

10. R
_ +
_
+ 1G 2G 3G
1H
1
2
G
H
+
+
C
Copyright © 2017 by Milap Bhanderi

11. R
_ +
_
+
21GG 3G
1H
1
2
G
H
+
+
C
Copyright © 2017 by Milap Bhanderi

12. R
_ +
_
+ 21GG 3G
1H
1
2
G
H
+
+
C
Copyright © 2017 by Milap Bhanderi

13. R
_ +
_
+
121
21
1 HGG
GG
− 3G
1
2
G
H
C
Copyright © 2017 by Milap Bhanderi

14. R
_ +
_
+
121
321
1 HGG
GGG
−
1
2
G
H
C
Copyright © 2017 by Milap Bhanderi

15. R
_ +
232121
321
1 HGGHGG
GGG
+−
C
Copyright © 2017 by Milap Bhanderi

16. R
321232121
321
1 GGGHGGHGG
GGG
++−
C
Copyright © 2017 by Milap Bhanderi

17. Copyright © 2017 by Milap Bhanderi