Page 368 - Electronic Mechanic - TP - Volume - 2

ELECTRONICS MECHANIC - CITS

MODULE 22: Servo motor

EXERCISE 237: Control servo motor

Objectives

At the end of this exercise you shall be able to:
• to learn the basic specifications of a servo motor
• to demonstration how to control a Servo Motor using a 555 timer IC.

Requirements

Tools/Equipments/Instruments
• Combination Plier 250mm - 1 No. • 555 Timer - 1 No.
• Screw Driver set 150mm - 1 Set. • 6 Volt battery - 1 No.
• Wire Stripper - 1 Set. • Two push-buttons resistors - 2 Nos.
Materials/Components • One transistor 1K, 4.7K, 33K, 10K,
68K, BC547) - 5 Nos.
• Servo motor - 1 No. • Capacitors 0.1uf - 1 No.

Procedure

The servo motor is a closed-loop mechanism that incorporates positional feedback in order to control the
rotational or linear speed and position. The motor is controlled with an electric signal, either analog or digital,
which determines the amount of movement which represents the final command position for the shaft.
Working Principle:
The position sensors provide a feedback signal corresponding to the present position of the load. This sensor
is normally a potentiometer that produces the voltage corresponding to the absolute angle of the motor shaft
through gear mechanism.

Advantages:

• The speed control characteristics of this motor are good.
• They generate less amount of heat.
• They offer high efficiency, more torque per weight, reliability & reduced RF noise.

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