Encoder Report

TITLE: ENCODER INSTRUCTIONAL AIMS: The trainees must be able to: 1. Describe the function of an encoder. 2. Design the internal circuitry for an encoder. TOOLS.EQUIPMENT AND MATERIALS: Breadboard, Power Supply, IC 74147,7432,7400,7408,LED and Jumper Wires DRAWING, DATA TABLES: Refer to pages with the procedure instructions. GENERAL INSTRUCTION: Trainees are going to examine the concept of a code converter using encoder. CONCEPT. An encoder performs a function that is the opposite of decoding. It receives one or more signals in an un-coded form and outputs a code that can be processed by another logic circuit.

EXERCISE 1 Four to Two Line Encoder. 1. One IC 7432 Quad 2-input OR gate onto the logic breadboard was inserted. 2. The circuit as shown below was constructed.

3. Data switches for the truth table of the circuit was set as below.The output indications of L1 and L2 was record as in the table. Four to Two Line Encoder Truth Table Inputs Outputs SW4= SW3= SW2= SW1= L2=B L1=A 3 2 1 0 0 0 0 1 0 0 0 0 1 0 0 1 0 1 0 0 1 0 1 0 0 0 1 1

EXERCISE 2 Basic Encoder Circuit : Decimal to Binary Code 1. IC 7408 AND gate and IC 7400 NAND gate was insert into logic lab breadboard. 2. The circuit was construct as below.

3. Data switches as in Decimal to Binary Code input table was set and the output indicator of A,B,C and C was recorded in the table.

Basic Encoder Truth Table : Decimal to Binary Code

I1 0 1 1 1 1 1 1 1 1

I2 1 0 1 1 1 1 1 1 1

I3 1 1 0 1 1 1 1 1 1

Encoder : Decimal to BCD Output Table INPUT OUTPUT I4 I5 I6 I7 I8 I9 A B C 1 1 1 1 1 1 0 0 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 0 0 1 0 1 1 1 1 1 0 1 0 1 0 1 1 1 1 0 1 0 1 1 0 1 1 1 0 1 1 1 1 1 0 1 1 0 1 1 1 1 1 1 0 1 1 0 0 1 1 1 1 1 0 1 0 0

D 1 0 1 0 1 0 1 0 1

EXERCISE 3 Encoder : Decimal to Binary Code. 1. One IC 74147 (ENCODER) DECIMAL to BINARY CODE was insert onto the logic lab breadboard. 2. The circuit was construct as in the paragraph below. 3. Data switches was set as in DECIMAL to BINARY CODE INPUT truth table.The output indicator of L1, L2, L3 and L4 was recorded.

Encoder : Decimal to Binary Output Table INPUT OUTPUT 1 2 3 4 5 6 7 8 9 A3=L A2=L A1=L =S1 =S2 =S3 =S4 =S5 =S6 =S7 =S8 =S9 4 3 2 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 1 1 0 1 1 0 1 1 1 1 1 1 1 1 0 1 1 1 0 1 1 1 1 1 1 0 1 1 1 1 1 0 1 1 1 1 1 0 1 1 1 1 1 1 0 1 1 1 1 0 0 1 1 1 1 1 1 0 1 1 1 0 0

A0=L 1 0 1 0 1 0 1 0

1 1

1 1

1 1

1 1

1 1

1 1

1 1

0 1

1 0

0 0

1 1

1 1

Question: 4. The 74147 Decimal to BCD Encoder yields a unique output _LOW___ for each input state detected. 5. The 74147 Decimal to CD Encoder has active LOW (LOW/HIGH)inputs and active LOW (LOW/HIGH) outputs. 6. Refer to the logic symbol below, determine the output level for the 74HC147 encode i. ii. iii.

I3 is LOW all other input are HIGH I3 and I7 is LOW and all other input are HIGH I9 is LOW all other input are HIGH

CONCLUSION: From the experiment, we could know more about the encoder that used in electronic nowadays. The IC of HIGH input or LOW input can represent by the bubble at their input or output. There was the way we learn more about the IC for encoder with construct it using schematic circuit.

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