Basic Elec. Engr Basic Elec. Engr. Lab . Lab ECS 204 ECS 204 - - PowerPoint PPT Presentation

• Asst. Prof. Dr. Prapun Suksompong

prapun@siit.tu.ac.th

1

Basic Elec. Engr Basic Elec. Engr. Lab . Lab

ECS 204 ECS 204

Lab 7

• Operational amplifier
• Inverting amplifier
• Summing Amplifier

Op-Amp 741

2

 OPerational AMPlifier

(1) Offset null + (2) Inverting input (3) Noninverting input (4) V- NC (8) V+ (7) Offset null (5) Output (6) Noninverting input Inverting input V+ , Positive power supply V- , Negative power supply Output (3) (2) (7) (4) (6)

(Not connected)

Placing op amps on the proto-board

3

 Plug in op amp chips so that they straddle the troughs on the

proto board.

 In this way, each pin is connected to a different hole set.

Powering the op amp

4

 The op amp must be powered by

voltage supplies.

 These supplies are often ignored

in op amp circuit diagrams for the sake of simplicity.

Powering the op amp

5

GND +5 V

• 5 V

Op amp tester

6

Part A: Inverting Amplifier

7

F

• i

R

R V V. R  

Part A: Inverting Amplifier

8

F

• i

R

R V V. R  

9

10

Part A: Inverting Amplifier

11

Demo: Clipping

12

Part B: Summing Am Amplifier plifier

13

 Note that you will need 4 DC Voltage Sources in this

part.

1 1 2 F 2

• 1

2

F F

• 1

2 1 2

R R V V V . R R         