LAB 3: Product Analysis

1
ENG H192 Hands-on Lab

• LAB 3 Product Analysis

2
Product Analysis
Objectives

• Combine previous lab experiences to better
  understand the workings of a completed product.
• Develop an appreciation for horsepower and
  wattage considerations in product design.
• Expand the library of electrical schematic
  symbols used to designate components.
• Develop reverse engineering skills.

3
Product Analysis
Contents

• Power Conversion and Approximation
• Schematic Components
• Motor Discussion

4
Power Conversion
watt for James Watt, abbr. W, unit of power, or
work done per unit time, equal to 1 joule per
second. It is used as a measure of electrical and
mechanical power. One watt is the amount of power
that is delivered to a component of an electric
circuit when a current of 1 ampere flows through
the component and a voltage of 1 volt exists
across it.
5
Power Conversion

• horsepower, unit of power in the English system
  of
• units. It is equal to 33,000 foot-pounds per
• minute or 550 foot-pounds per second or
  approximately 746 watts. The term horsepower
• originated with James Watt, who determined by
• experiment that a horse could
• do 33,000 foot-pounds of work
• a minute in drawing coal from
• a coal pit.

6
Schematic Symbols
Commonly Used Symbols
DC Source
AC Source
Motor
Ground
Resistor
Capacitor
Fuse
SPST Switch
N.C. Push Button Switch
N.O. Push Button Switch
Female Connector
Male Connector
7
Part II
Shaded-Pole Motor Lecture
8
Breakaway View
Stator Winding
Rotor
Laminated Core
Poles Shaded with Copper Wire
9
Shading Theory
10
Shading Theory
11
Shading Theory
12
Shading Segments
13
Flux Wave Rotation
14
Motor Speed
Motor theory tells us that the speed of an ac
motor is directly proportional to the frequency
and inversely proportional to the number of poles
as follows Thus, for a 2-pole motor running
at 50 hz
15
Motor Slip
The rotor of an induction motor will not rotate
at the theoretical speed due to slip. The
equation for slip is Thus, if the anticipated
rpm was 3600 and the actual rpm was 3440