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A COURSE IN BASIC ELECTRICITY

A P ro je c t P re s e n te d to t h e F a c u l t y o f t h e S c h o o l o f E d u c a ti o n The U n i v e r s i t y o f S o u th e r n C a l i f o r n i a

In P a r t i a l F u lfillm e n t o f t h e R e q u ir e m e n ts f o r t h e D e g re e M a s te r o f S c ie n c e i n E d u c a ti o n

Ly B e r tr a m Solom on A u g u s t 1950

UMI Number: EP46584

All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion.

UMI Disssrtation Publishing

UMI EP46584 Published by ProQuest LLC (2014). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code

uest ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346

(B i

>*'/

sur*

P*

This project report, w ritten under the direction of the candidate’s adviser and approved by him, has been presented to and accepted by the Faculty of the School of Education in partial fulfillm ent of the requirements fo r the degree of M aster of Science in Education.

Date.

...............................

A dviser

Dean

ii TABLE OF CONTENTS CHAPTER

PAGE PART I .

ELECTROSTATICS

HOW TO MAKE DEVICES THAT OPERATE BY STATIC ELECTRICITY I.

HOW TO MAKE A PITH BALL AND ELECTROSCOPE STAND .........................

How t o f o r m t h e b a s e

2

2

1.

BASE:

2.

SUPPORT:

3*

PITH BALL:

k.

ELECTROSCOPE:

5.

ASSEMBLY:

How t o p u t s t a n d t o g e t h e r

.

.

b

6.

OPERATION:

How t o t e s t f o r c h a r g e s

.

.

b

How to b e n d t h e

2

s u p p o r t arm

b

How t o s h a p e t h e p i t h b a l l How t o f a b r i c a t e t h e l e a v e s

b

HOW TO MAKE AN ELECTROPHORUS

7

1.

D ISC:

How to s h a p e t h e d i s c .........................

7

2.

HANDLE:

How to m ake t h e h a n d le ....................

7

3.

CONSTRUCTION: e le c tro p h o ru s

k.

OPERATION:

How t o a s s e m b le t h e .................................................................

How t o u t i l i z e PART I I .

th e e le c tr o p h o r u s

9 9

MAGNETISM

HOW TO MAKE MAGNETIC PROJECTS 12

HOW TO MAKE A HORSESHOE MAGNET 1.

MATERIAL:

2.

SHAPE:

3.

'MAGNETISM:

....................

12

..............................

12

How t o m a g n e tiz e th e s h a p e d s t e e l

lb

How t o

s e l e c t th e m e t a l

How t o b e n d t h e s t e e l

ill CHAPTER

4.

PAGE

4.

FIN ISH :

5.

USE:

How t o p a i n t t h e h o r s e s h o e m a g n e t

How t o do t h i n g s w i t h t h e m a g n e t

.

. . .

14

HOW TO MAKE A MAGNETIC C O M P A S S ................................ 1.

BODY:

How t o m ake t h e b a s e

2.

COVER:

3.

DIAL:

4.

NEEDLE:

5.

CONSTRUCTION:

16

...................................

16

....................

16

...................................

18

How t o m ake t h e c o v e r l i d How t o m ake t h e f a c e

How t o m ake t h e p o i n t e r ..................

18

How t o p u t t h e co m p ass

t o g e t h e r ............................................................................. 6.

APPLICATION:

14

19

How t o f i n d d i r e c t i o n s w i t h

t h e c o m p a s s . . ................................................................... PART I I I .

19

ELECTRO-CHEMISTRY

HOW TO MAKE BATTERY EQUIPMENT 5.

6.

HOW TO MAKE A BATTERY 1.

JAR:

2.

ELECTRODES:

3.

ELECTROLYTE:

4.

ASSEMBLY:

5*

APPLICATION:

...........................................................

How t o a d a p t a c o n t a i n e r

22

.........................

How t o make t h e e l e c t r o d e s

22

. .

22

How t o p r e p a r e t h e e l e c t r o l y t e .

22

How t o p l a c e t h e p a r t s t o g e t h e r

.

24

How t o h o o k b a t t e r i e s i n

s e r i e s a n d p a r a l l e l ....................................................

24

HOW TO MAKE A HYDROMETER F L O A T ................................

27

1.

CONSTRUCTION:

How t o

sh ap e th e f l o a t

. . .

27

iv i&E How t o w e i g h t t h e f l o a t .........................

WEIG-HT: SCALE: USE:

How t o m a rk t h e g r a d u a t i o n s

..

. .

27

. . . .

29

..................................................

32

How t o c h e c k a s t o r a g e b a t t e r y PART IV .

27

ELECTRICAL MEASUREMENT

HOW TO MAKE METERS TO MAKE A GALVANOMETER BASE:

How t o make th e b a s e

FORM:

How t o p r e p a r e t h e c o i l fo rm

COIL:

How t o w in d t h e c o i l

ASSEMBLY:

................................... . . . .

32

...................................

3^

..............................

3^

How t o p u t t o g e t h e r

OPERATION:

32

How t o m e a s u re c u r r e n t

34

. . . . . .

TO MAKS A METER MOVEMENT.............................................

36

PANEL:

36

How t o b u i l d t h e m e te r m ovem ent m ount .........................

36

...................................

38

FORM:

How t o make t h e c o i l fo rm

COIL:

How t o w in d t h e c o i l

VANE:

How t o fo rm t h e t i n v a n e

.........................

38

.

38

How t o m o u n t t h e p a r t s

. . .

39

CALIBRATION:

How t o p r e p a r e t h e s c a l e

. . .

39

UTILIZATION:

How t o m e a s u re v o l t a g e a n d

....................................................................................

39

INDICATOR:

How t o a t t a c h t h e w ir e p o i n t e r

CONSTRUCTION:

a m p e ra g e

V

CHAPTER

PAGE PART V.

ELECTROMAGNETISM

HOW TO MAKE ELECTROMAGNETIC APPARATUS Q.

10.

HOW TO MAKE AN ELECTROMAGNET.............................................

43

1.

BASE:

How t o o o n s t r u c t t h e b a s e .............................

43

2.

COIL:

How t o

....................................

43

sh ap e th e p a r t s o f th e s w itc h

45

3.

SWITCH:

4.

ASSEMBLY:

m ake t h e c o l l

How t o

How t o p l a c e t h e p a r t s on th e

b a s e ...............................................................................................

45

5.

CONNECTIONS:

. . .

45

6.

APPLICATIONS:

. . . .

45

How t o w ir e t h e p r o j e c t How t o p i c k u p m e t a l

HOW TO MAKE A SIMPLE BUZZER 1.

BASE:

2.

SUPPORTS:

3.

COIL:

4.

ARMATURE:

5.

CONSTRUCTION:

6.

WIRING:

7.

..............................................

How t o m ake t h e b a s e

....................................

How t o fo rm t h e m o u n ts

How t o m ake t h e c o i l How t o

47 4?

.....................

49

....................................

49

s h a p e t h e a r m a tu r e

. . . .

How t o a s s e m b le t h e p a r t s

.

50 .

50

e l e c t r i c a l l y ...........................................................................

51

How t o c o n n e c t t h e p a r t s

OPERATION:

How t o h o o k y o u r b u z z e r i n

c i r c u i t s ..................................................................................... PART V I.

51

CIRCUIT WIRING

HOW TO MAKE CIRCUIT CONTROL DEVICES 11.

HOW TO MAKE A SAFETY SWITCH

..............................................

55

vl CHAPTER

PACE

1.

BASE:

How t o p r e p a r e t h e b a s e ..............................

2.

CONTACT:

3.

SWITCH:

k.

MOUNTING-:

How t o

shape t h e m e t a l s t r i p

How t o make t h e a r m a t u r e How t o f a s t e n

55

. . .

55

....................

57

th e p a r t s to th e

b a s e .............................................................................................. 5.

HOOK UP:

How to e l e c t r i c a l l y c o n n e c t t h e

s w itc h 6. 12.

57

.....................................................................................

SET UP:

How t o o p e r a t e t h e

s a f e ty s w itc h

57

.

57

HOW TO MAKE A LIGHT D IM M E R ...................................................

60

1.

MOUNT:

How t o m ake t h e b a s e .........................

60

2.

ROTOR:

How t o fo rm t h e c o n t a c t arm

3.

LINKS:

How t o p r e p a r e t h e r e s i s t a n c e l i n k s

4.

CONSTRUCTION:

. . . .

60 .

How t o p u t t h e p a r t s t o g e t h e r .

PART V I I .

60 62

ELECTRICAL POWER

HOW TO MAKE MOTORS AND GENERATORS 13.

HOW TO MAKE A GENERATOR............................................................. 1.

B A S E : ...............................................................................................

2.

FIELD:

How t o c o n s t r u c t t h e f i e l d m agnet

3.

ROTOR:

How t o b u i l d t h e a r m a t u r e

COMMUTATOR: 5. 1L.

CONTACTS:

How t o p r e p a r e t h e b r u s h e s

HOW TO MAKE A TOY MOTOR

65 .

.....................

How t o make t h e c o m m u ta to r

65

. . . . .

........................................................

65 67 67 67 70

OHASIS:

How t o

FIELD:

c o n s t r u c t t h e b a s e ....................

How t o m ake t h e f i e l d

ARMATURE:

..

. .

70

.. . .

70

. .

72

....................

72

How t o b u i l d t h e a r m a tu r e

COMMUTATOR:

How t o fo rm t h e c o m m u ta to r

CONSTRUCTION: WIRING:

c o lls

How t o p u t t o g e t h e r

72

How t o p u t t h e m o to r I n o p e r a t i o n

PART V I I I .

70

POWER DISTRIBUTION

HOW TO MAKE ELECTROMAGNETIC FORCE DEVICES TO MAKE A STEP-DOWN TRANSFORMER

.........................

76

CORE:

.........................

76

How t o c o n s t r u c t t h e c o r e

PRIMARY:

How t o w in d t h e p r im a r y c o i l

SECONDARY: BASE:

.

. .

76

. . .

78

...................................

78

How t o w in d t h e s e c o n d a r y

How to s h a p e th e b a s e

CONTACTS:

How t o m ake t h e t e r m i n a l s t r i p

78

MOUNTING:

How t o a s s e m b le t h e p a r t s

78

CONNECTIONS:

. . . .

How to w i r e t h e t e r m i n a l s t r i p .

79

TO MAKE A SHOCKING TRANSFORMER..............................

81

BASE:

How

to b u i l d th e b a se

...................................

81

CORE:

How

to p r e p a r e th e c o re

..............................

81

COIL:

How

t o w in d th e p r i m a r y a n d s e c o n d a r y

. . .

...........................................................................

81

INTERRUPTER:

How t o m ake t h e c i r c u i t b r e a k e r

83

tu rn s

v lii CHAPTER 5»

PAGE ASSEMBLY:

How t o f a s t e n

t h e p a r t s on t h e

b a s e ............................................ 6.

GRIPS;

7.

HOOK UP:

83

How t o c o n s t r u c t t h e h a n d g r i p s How t o

PART IX .

c o n n e c t th e d e v ic e

• .

. . . .

83 83

THERMO-ELECTRICAL EQUIPMENT

HOW TO MAKE CURRENT CONSUMING APPLIANCES 17.

HOW TO MAKE A SOLDERING I R O N ..............................................

87

1.

SHANK:

87

2.

HOUSING:

How t o d r i l l h o l e s i n t h e s h a n k . . . How t o f i t h o u s in g

a id sh an k

t o g e t h e r ..................................................................................... 3.

HANDLE:

How t o

4.

CORE:

5.

ELEMENT:

6.

CONSTRUCTION:

s h a p e t h e h a n d l e .........................

How t o m ake t h e c o p p e r t i p

89

How t o w in d t h e h e a t i n g e le m e n t . .

89

How t o p l a c e t h e p a r t s

OPERATION:

How t o

.......................................

89

s o ld e r w ith th e s o ld e r in g

i r o n .............................................................................................. 18.

HOW TO MAKE AN ELECTRIC LIGHT FLASHER 1.

BASE:

2.

THERMOSTAT:

3.

CONTACTS:

4.

89

....................

to g e t h e r an d w ire 7.

87

How t o m ake t h e b a s e

90

.....................

92

...................................

92

How t o b u i l d a b i - m e t a l l i c

s trip

92

m o u n t s .........................................................................................

92

COIL:

9^

How t o

c o n s tr u c t th e c o n ta c t

How t o w in d t h e h e a t i n g e le m e n t

. . .

ix CHAPTER 5*

PAGE ASSEMBLY:

How t o PART X.

p u t p a r ts to g e th e r

. . . .

94

COMMUNICATION

HOW TO MAKE DEVICES THAT INTERCHANGE SOUND AND ELECTRICAL ENERGY 19.

HOW TO MAKE A CARBON MICROPHONE 1.

MIKE:

How t o m ake t h e m ic ro p h o n e u n i t

2.

BASE:

How t o s h a p e th e

3.

HOLDER:

How

m ount

20.

. . ........................ . . .

97 97

s t a n d .........................

97

t o c o n s t r u c t th e m ic ro p h o n e

..........................................................................................

4.

CONSTRUCTION:How t o a s s e m b le t h e p a r t s

5.

CONNECTIONS:

6.

USE:

99

..

99

How t o h o o k u p t h e m ic ro p h o n e .

99

How t o o p e r a t e t h e m i c r o p h o n e .....................

99

HOW TO MAKE A CRYSTAL S E T .............................................................. 102 1.

CHASIS:

2.

COIL:

3.

SELECTOR:

4.

CRYSTAL:

5.

ASSEMBLY:

6.

HOOK UP:

BIBLIOGRAPHY

How

t o b u i l d t h e b a s e ........................... 102

How t o m ake t h e c o i l How t o fo rm th e

.......................................... 102 s l i d e r .....................10 4

How t o m ount t h e c r y s t a l

. . . . .

104

How t o p l a c e t h e p a r t s

on t h e b a s e

104

How t o c o n n e c t t h e p a r t s ........................... 1 0 4

..........................................................................

107

X

L IST OF FIGURES FIGURE

PAGE

1.

PITH BALL AND ELECTROSCOPE S T A N D ..............................

3

2.

ELECTROPHORUS

..........................................................................

8

3.

HORSESHOE MAGNET

......................................................

13

4.

MAGNETIC C O M P A S S .....................................................................

15

5.

BATTERY

.........................................................................................

23

6.

HYDROMETER F L O A T .....................................................................

28

7.

GALVANOMETER...............................................................................

33

8.

METER MOVEMENT..........................................................................

37

9.

ELECTROMAGNET

..........................................................................

44

10.

SIMPLE BUZZER

..........................................................................

48

11.

SAFETY SWITCH

..........................................................................

56

12.

LIGHT DIMMER

13.

. . . . .

......................................................

6l

GENERATOR

...................................................................................

66

14.

TOY MOTOR

....................................................................................

71

15.

STEP-DOWN TRANSFORMER

......................................................

77

16.

SHOCKING TRANSFORMER...........................................................

82

17.

SOLDERING I R O N ..........................................................................

88

18.

ELECTRIC LIGHT FLASHER

........................

93

19.

CARBON MICROPHONE

................................................................

98

20.

CRYSTAL SET

...............................................................................

103

. . . . . .

xi PREFACE TO TEACHERS T h is c o u r s e h a s b e e n w r i t t e n w i t h t h e h o p e t h a t I t w i l l p r o v i d e t h e l e a r n e r w i t h a m ore p r a c t i c a l a n d f u n c t i o n ­ a l le a rn in g p ro c e ss in th e f i e l d o f b a s ic e l e c t r i c i t y .

A l­

th o u g h t h i s c o u r s e i s d e s i g n e d p r i m a r i l y f o r a n e l e c t r i c s h o p , t h e same m a t e r i a l a n d p r o j e c t m e th o d c a n b e u s e d i n g e n e r a l s c ie n c e and p h y s ic s c l a s s e s . T h e re a r e n u m ero u s e l e c t r i c a l d e v i c e s w h ic h c o u l d h a v e b e e n In c lu d e d in e a c h o f th e p a r t s .

Due t o t i m e a n d s p a c e

th e s e d e v ic e s have n o t b e e n p r e s e n te d a s i n d iv i d u a l c h a p te r s b u t a r e m e n tio n e d a s an a c t i v i t y f o r l e a r n i n g t h e sam e p r i n ­ c ip le .

T he p r e s e n t a t i o n o f two d e v i c e s u n d e r e a c h p r i n c i p l e

g iv e s th e le a r n e r a s u f f i c i e n t sp re a d and p re v e n ts lim ite d c o v e ra g e o f th e

s u b je c t by le a rn in g by s p e c ia l c a s e .

x il PREFACE TO STUDENTS You a r e on y o u r way t o c o n q u e r t h i s m y s t i f y i n g f i e l d of e le c tric ity

b y b u i l d i n g d e v i c e s w h ic h a o t u a l l y w o rk a n d

c a n b e u s e d f o r some p r a c t i c a l p u r p o s e . T h is c o u r s e o f f e r s y o u p r o j e c t s t o c o n s t r u c t ,

p o s s ib le

h o b b i e s , l o t s o f f u n , w ay s o f e a r n i n g m oney, w ay s o f s a v in g tim e ,

s a f e ty fro m e l e c t r i c a l h a z a rd s and c ra f ts m a n s h ip . Y o u r p r e s e n t l i f e d e p e n d s v e r y h e a v i l y on e l e c t r i c i t y

a n d you n e e d t o l e a r n a b o u t e l e c t r i c a l p r i n c i p l e s now m ore th a n e v e r b e f o r e . w o rk .

H ere i s a n i n t e r e s t i n g way t o

le a r n th e

1

PART I .

ELECTROSTATICS

HOW TO MAKE DEVICES THAT OPERATE BY STATIC ELECTRICITY L i g h t n i n g m akes you Jump b u t w h a t m akes l i g h t n i n g Jump?

Why do s t a t i c

c h a r g e s b e h a v e a s t h e y do ?

c o n tro l s t a t i c e le c t r ic ity ?

How c a n we

The a n s w e r s t o t h e s e q u e s t i o n s

w i l l be y o u rs a f t e r you h av e b u i l t an d o p e ra te d th e e le c tr o ' s t a t i c d e v i c e s i n t h e n e x t tw o c h a p t e r s .

CHAPTER 1 HOW TO MAKE A PITH BALL AND ELECTRISCOPE STAND A.

MOTIVATION:

B e n e f i t s d e r i v e d f r o m t h i s l e s s o n on how

t o b u i l d a p i t h b a l l a n d e l e c t r o s c o p e s ta n d * 1.

COMFORT:

P r e v e n tio n o f sh o c k s due to

s t a t i c e le c ­

tric ity .

B.

2.

A LONGER L IFE :

3.

AMUSEMENT:

DIRECTION:

P ro te c tio n a g a in s t lig h tn in g .

T r i c k s you c a n p e r f o r m w i t h t h e s t a n d .

Some h e l p f u l h i n t s i n c o n s t r u c t i n g t h e p i t h

b a l l an d e le c tr o s c o p e s ta n d . 1.

BASE: a.

(S e e F i g u r e l )

How t o fo rm t h e b a s e .

Saw w ood t o

s iz e in a m ite r box.

b.

C h eck f o r s q u a r e n e s s w i t h a t r y

sq u a re .

c.

M ark t h e b e s t s u r f a c e a s t h e t o p .

d.

L o c a te t t e

e.

D r i l l a h o le s l i g h t l y s m a lle r th a n th e d ia m e te r

c e n te r o f th e to p s u r f a c e .

o f t h e s u p p o r t arm w i r e .

2.

f .

F i l e o r s a n d p a p e r a c h a m p h e r on t h e t o p s u r f a c e .

g.

S a n d p a p e r a l l s u r f a c e s t o a sm o o th f i n i s h .

h.

A p p ly s h e l l a c o r l a c q u e r .

SUPPORT:

How t o b e n d t h e s u p p o r t a rm .

a.

C u t th e w ire to le n g th .

b.

B en d t h e c u r v e w i t h a r o u n d n o s e p l i e r s .

c.

S h a p e t h e h o o k w i t h a c o m b in a tio n a n d r o u n d n o s e

At S !J R £~ / PiTff BAiL STAND

p lie rs . d.

F l a t t e n t h e e n d w i t h a b a l l p e e n ham m er.

e.

F i l e th e ends to sh ap e.

PITH BALL:

How t o

sh ap e t h e p i t h b a l l .

a.

C ut th e p i t h o r c o rk in to

sq u a re c u b e s.

b.

S an d p ap er th e c o m e r s u n t i l a ro u n d b a l l i s sh ap ed .

c.

A tta c h a

d.

Make

s i l k th re a d to

tw o o f t h e s e .

ELECTROSCOPE: a.

th e b a ll w ith g lu e .

How t o f a b r i c a t e

C ut th e s t r i p

th e le a v e s .

o f a lu m in u m f o i l w i t h a s c i s s o r s .

b.

B en d

th e s t r i p i n h a l f .

c.

T rim

th e en d s even a n d s q u a re .

ASSEMBLY: a.

How t o p u t s t a n d t o g e t h e r .

F o rc e th e w ir e s u p p o rt i n t o th e h o le i n th e to p o f th e b a s e .

b.

A tta c h th e p i t h b a l l s by lo o p in g a ro u n d th e h o o k o n t h e a rm .

c.

P l a c e t h e e l e c t r o s c o p e l e a v e s on t h e f l a t t e n e d p o r tio n o f th e hook.

OPERATION: a.

How t o t e s t f o r c h a r g e s .

C h a rg e t h e p i t h b a l l n e g a t i v e l y b y t o u c h i n g i t w i t h a comb t h a t h a s b e e n r u b b e d w i t h f u r .

b.

C h a rg e i t p o s i t i v e l y w i t h a g l a s s r o d r u b b e d w ith s i l k .

X-}

c.

C h a rg e t h e e l e c t r o s c o p e l e a v e s i n

t h e same

m a n n e r.

7.

(1 )

U n lik e f o r c e s a t t r a c t e a c h o t h e r .

(2 )

L ik e f o r c e s r e p e l e a c h o t h e r .

SOURCES: a.

W here t o g o t o o b t a i n f u r t h e r a s s i s t a n c e

B o o k s:

Jo h n so n 2 4 -4 5 ;

G h ira rd i 3 2 -3 4 ;

C ra w fo rd 5 5 -5 6 ♦ b.

M o tio n p i c t u r e s :

P rin c ip le s o f E le c t r i c i ty

a

G .E . 1945 20 m in s d c o l o r l o a n ; W hat I s E l e c t r i c i t y . c. C.

F ilm s t r i p :

ACTIV ITIES:

W e s tin g h o u s e 20m in s d .

S ta tic E le c tr ic ity .

Some l e a r n i n g

Jam H andy.

e x p e rie n c e s to en h an ce th e

b u ild in g o f th e s t a n d . 1.

C o n s tru c t th e d e s c r ib e d s ta n d .

2.

B u ild a l a r g e r s ta n d f o r th e s c h o o l.

3*

D e s ig n a s t a n d o u t o f s c r a p m a t e r i a l t h a t you may h a v e a t hom e.

4. D.

Draw a d ia g ra m o f t h e s t a n d .

EVALUATION:

Some q u e s t i o n s t o d e te r m i n e t h e l e a r n i n g

t h a t h a s ta k e n p l a c e . 1.

TRUE-FALSE:

P la c e X in th e c o r r e c t sp ace f o r tr u e

o r fa ls e . T a.

( )(

F ) You c a n make t h e e l e c t r o s c o p e w o rk w i t h

th e p i t h b a l l s , b.

( )(

) To c h a r g e t h e p i t h b a l l p o s i t i v e l y you s h o u ld t o u c h t h e b a l l w i t h a comb r u b b e d w ith f u r .

BEST ANSWER:

P l a c e t h e n u m b er o f t h e c o r r e c t a n s w e r

in th e p a re n th e s e s . a.

( ) The e l e c t r o s c o p e f o i l l e a v e s (1 ) C o p p e r.

(2 ) B r a s s .

s h o u ld

b e made o f

(3 ) A lum inum .

(^ ) S ilv e r . b.

( ) The s t a n d s h o u l d b e u s e d t o d e t e r m i n e t h e m a t e r i a l 1s : (l)

S tre n g th .

( 2 ) C h arg e*

(3 ) S t r e s s .

( 4 ) W e ig h t. RATING- SCALE:

Have t h e i n s t r u c t o r c h e c k a n d g r a d e

e a c h o f th e f o llo w in g : a. b.

( ) B ase. (

) S u p p o rt.

c.

( ) E le c tro s c o p e L eav es.

d.

( ) O p e ra tio n .

(

) T o ta l.

7 CHAPTER 2 HOW TO MAKE AN ELECTROPHORUS A.

MOTIVATION: tro s ta tic 1.

R e w a rd s f o r s t u d y i n g t h i s s e c t i o n o n e l e c ­

e le c tric ity *

POPULARITY:

E x h ib itio n o f th e t r i c k s t h a t can be

w o rk e d w i t h t h e e l e c t r o p h o r u s w i l l m ake y o u t h e l i f e o f th e p a rty * 2.

CRAFTSMANSHIP:

E v id e n c e t o y o u r f r i e n d s a n d f a m i l y

t h a t y o u e a n make a n e l e c t r o p h o r u s . 3*

CONTROL:

P e rfo rm a n c e o f s t a t i c c h a rg e s in a c c o rd a n c e

to y o u r w is h e s . B»

DIRECTIONS: o ru s. 1.

(S e e F i g u r e 2 )

D ISC : a.

P r o c e d u r e i n v o l v e d i n m ak in g a n e l e c t r o p h ­

How t o

L a y o u t a c i r c l e on t h e s h e e t o f m e t a l w i t h a com pass.

b.

sh a p e th e d i s c .

(A c o f f e e c a n c o v e r c a n b e u s e d . )

C ut o u t th e c i r c l e w ith a v ia tio n o r s c r o l l t i n s n ip s .

c. 2.

F ile o f f a l l th e b u r r s .

HANDLE:

How t o m ake t h e h a n d l e .

a.

C u t o f f l e n g t h fro m a d o w e l r o d w i t h a saw .

b.

S h a p e t h e d o w e l w i t h a s l o y d k n i f e by w h i t t l i n g .

c.

F i l e th e le n g th in to f i n a l sh ap e.

d.

R ound t h e e n d w i t h a f i l e .

8



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e.

S a n d p a p e r a l l s u r f a c e s sm o o th .

f.

A p p ly s h e l l a c o r l a c q u e r .

CONSTRUCTION: a.

How t o a s s e m b le t h e e l e c t r o p h o r u s .

P l a c e a s m a ll am o u n t o f s e a l i n g w a s on t h e c e n ­ t e r o f th e d i s c .

b.

H e a t t h e d i s c o v e r a lo w f la m e u n t i l t h e wax m e lts .

c.

P r e s s t h e h a n d l e a g a i n s t t h e wax i n a n u p r i g h t p o s itio n .

d.

A llo w t h e wax t o s o l i d i f y .

e.

C le a n t h e

s u r f a c e o f t h e e l e c t r o p h o r u s w i t h some

s t e e l w o o l. OPERATION:

How t o

u tiliz e

th e e le c tro p h o ru s .

a.

C ut a p ie c e o f p h o to g ra p h ic f ilm t o s i z e .

b.

Rub t h e f i l m

w ith a p ie c e o f f u r to c h a rg e th e

film . c.

P la c e th e d i s c f l a t a g a in s t th e f ilm .

d.

T ouch y o u r f i n g e r to t h e to p s u r f a c e o f th e d is c (1 )

The n e g a t i v e c h a r g e s a r e g r o u n d e d t h r o u g h y o u r body le a v in g th e d is c p o s i t i v e l y c h a rg e d .

(2 ) e.

T e s t th e c h a rg e w ith an e le c tr o s c o p e .

SOURCES: a.

T h is c h a r g e s th e e le c t r o p h o r u s b y in d u c tio n

B o o k s:

W here t o g e t f u r t h e r a s s i s t a n c e , J o h n s o n 24—2 5 ; Q - h ir a r d i 3 2 -3 4 '.

10 *

b.

M o v ie s :

Summer S to rm *

M odern 19^-6 15m in s d

lo a n . c.

F ilm s t r i p :

A d v e n tu r e s I n E l e c t r o n s .

G -E . c o l o r . C.

A CTIV ITIES:

Some w o rk t o do a s p r a c t i c e I n b u i l d i n g a n

e le c tro p h o ru s . 1.

C o n s tru c t th e e le c tr o p h o r u s a s o u tlin e d In t h i s c h a p te r.

2. 3. D.

Make a n e l e o t r o p h o r u s o f a d i f f e r e n t d e s i g n . S k e tc h an e le c tr o p h o r u s and l a b e l a l l th e p a r t s .

EVALUATION: 1.

M e a su re m e n t o f w h a t h a s b e e n l e a r n e d .

TRUE-FALSE:

P la c e X In th e c o r r e c t sp a ce f o r tr u e

or fa ls e . 2.

BEST ANSWER:

P l a c e t h e n u m b er o f t h e c o r r e c t a n s w e r

in th e p a re n th e s e s . 3.

RATING SCALE:

H ave t h e I n s t r u c t o r c h e c k a n d g r a d e

e a c h o f th e fo llo w in g : a.

(

P is e .

b.

(

H a n d le .

c.

(

C o n s tru c tio n

d.

(

F in is h .

e.

(

O p e ra tio n .

(

T o ta l.

11

PART I I .

MAGNETISM

HOW TO MAKE MAGNETIC PROJECTS Why d o e s a c o m p a ss p o i n t n o r t h ?

How d o e s o n e p i e c e

o f m e t a l a t t r a c t a n d p i c k up a n o t h e r p i e c e o f m e t a l ?

The

a n sw e rs to th e s e q u e s tio n s w i l l be c l e a r a f t e r you have c o n s tru c te d and u t il i z e d te rs .

t h e d e v i c e s i n t h e n e x t tw o c h a p ­

12 CHAPTER 3 HOW TO MAKE A HORSESHOE MAGNET A.

MOTIVATION:

A t t a i n m e n t s g a i n e d fro m t h i s u n i t o n

m a g n e ts . 1.

ECONOMY OF TIME:

N a lls o r p in s t h a t have b een

d r o p p e d c a n b e p i c k e d up m o re q u i c k l y . 2.

MONEY:

3.

MASTERY:

P r o je c t can be s o ld . M a g n e tis m c a n b e c o n t r o l l e d a n d m ade to

w o rk f o r y o u . B.

DIRECTIONS: m a g n e t. 1.

2.

M e th o d s I n v o l v e d I n p r e p a r i n g a h o r s e s h o e

(S ee F ig u r e 3)

MATERIAL:

How t o

s e l e c t th e m e ta l.

a.

C u t o f f t o l e n g t h w i t h a h a c k saw .

b.

Be s u r e t h e m e t a l I s t o o l s t e e l .

c.

F ile th e ends sq u a re .

SHAPE:

How t o b e n d t h e s t e e l .

a.

L o c a te t h e c e n t e r .

b.

H e a t t h e s t o c k on e a c h s i d e o f c e n t e r t o a c h e r r y red .

c.

S h a p e t h e h o r s e s h o e b y ham m ering t h e m e t a l on a n a n v il. H a rd e n t h e h o r s e s h o e b y h e a t i n g t o

a ch erry re d

a n d p l u n g in g i t I n t o o i l im m e d ia te l y . F i l e th e en d s o f th e h o rse sh o e .

13

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14 & 3.

F i n i s h t h e e n d s w i t h em ery c lo th *

MAGNETISM:

How t o m a g n e tiz e t h e s h a p e d s t e e l *

a.

P la c e th e h o rse sh o e i n an e le c tr o m a g n e tic c o il*

b.

T e s t th e s t r e n g t h o f th e f i e l d w ith a co m p ass.

c.

M ark t h e p o l e s o f t h e m a g n e t w i t h a s p o t o f p a in t.

4.

FIN ISH : a.

How t o p a i n t t h e h o r s e s h o e m a g n e t.

P a i n t t h e b ody o f th e m agnet w ith m e t a l l i c p a in t•

b. 5.

L eave t h e en d s u n p a in te d .

USE:

How t o do t h i n g s w i t h t h e m a g n e t.

a.

P i c k u p m e t a l o b j e c t s w i t h t h e m a g n e t,

b*

M a g n e tiz e s c r e w d r i v e r t i p s b y r u b b i n g m a g n e t o n t h e s u r f a c e t o b e m a g n e tiz e d .

c.

P la c e a p ie c e o f p a p e r o v e r th e m agnet and s p r in k le iro n f i l i n g s to see th e l in e s o f f o r c e .

6.

SOURCES: a.

S e l e c t e d i n f o r m a t i o n on m a g n e ts .

B o o k s:

G h i r a r d l 1 0 6 -1 1 5 ;

Jo n e s 6 7 -7 6 ;

Jo h n so n 1 -2 1 . b.

M o v ie s :

E le c t r o n - A n I n t r o d u c t i o n .

C a s t l e 1 9 4 4 16 m in s d ; E x c u r s i o n s i n S c ie n c e #3*

G .E . 1 9 3 5 -1 9 4 2

lO m in s d . C.

A CTIV ITIES:

P r o j e c t s t o c o m p le te so a s t o u n d e r s t a n d

t h e p r e p a r a t i o n o f a h o r s e s h o e m a g n e t*

15

D.

1.

P r e p a r e th e m agnet a s I n s t r u c t e d .

2.

B u i l d a b a r m agne t .

3*

Draw t h e m a g n e t w i t h t h e l i n e s o f f o r c e i n d i c a t e d .

EVALUATION:

A p p r a is a l o f th e le a r n in g t h a t sh o u ld have

d e v e lo p e d a s a r e s u l t o f t h i s w o rk . 1.

TRUE-FALSE:

P l a c e X in t h e c o r r e c t s p a c e f o r t r u e

or fa ls e . 2.

BEST ANSWER:

P l a c e t h e num ber o f t h e c o r r e c t a n s w e r

in th e p a re n th e s e s . 3.

RATING- SCALE:

H ave t h e i n s t r u c t o r c h e c k a n d g r a d e

e a c h o f th e f o llo w in g : a.

( ) Shape.

b.

( ) M a g n e tism .

c.

( ) F in is h .

d.

( ) O p e ra tio n .

(

) T o ta l.

16 CHAPTER 4 HOW TO MAKE A MAGNETIC COMPASS A.

MOTIVATION:

V a lu e s d e r i v e d fro m u n d e r s t a n d i n g t h e -p rin ­

c i p l e s a n d t h e b u i l d i n g o f t h e m a g n e tic c o m m a s . 1.

HIKING:

D ir e c tio n s can b e fo u n d w ith t h i s p o r ta b le

com p ass. 2.

AMUSEMENT:

The c o m p a ss c a n b e g i v e n t o a y o u n g s t e r

a s a to y . 3.

POPULARITY: n e tic

B.

c o m p a ss.

DIRECTIONS:

BODY: a.

S t e p s t o f o l l o w i n b u i l d i n g a m a g n e tic

(S e e F i g u r e b)

co m p ass. 1.

S t u n t s c a n b e p e r f o r m e d w i t h t h e mag­

How t o make t h e b a s e .

L a y o u t a c i r c l e on t h e w ood w i t h a d ra w in g com­ p ass.

b.

C u t o u t t h e c i r c l e w i t h a c o p in g saw .

c.

C h e ck t h e s i d e s a g a i n s t t h e n e ss w ith a t r y

d.

s u rfa c e s f o r sq u a re ­

sq u a re .

D r i l l th e h o le s in l i n e w ith th e d ia m e te r o f th e c i r c l e a c r o s s t h e g r a i n o f t h e w ood.

2.

e.

F i l e t h e c u r v e d s u r f a c e s t o a sm o o th f i n i s h .

f.

S an d p ap er a l l th e s u r f a c e s .

g.

A p p ly a c o a t o f c l e a r l a c q u e r .

COVER:

How t o m ake t h e c o v e r l i d .

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b.

C u t th e two e n d s o f t h e c a r d b o a r d .

c.

B end t h e b o d y I n t o s h a p e .

d.

P l a c e t h e e n d s on t h e b o d y .

e.

G lu e t h e f l a p s down on t h e e n d s .

f.

S h e lla c th e f i n i s h e d fo rm .

COIL:

How t o w i n d t h e c o i l .

a.

C ut o f f l e n g t h o f d o o r b e l l w i r e .

b.

P l a c e t h e f o r m o n a w ood f o r m t o k e e p t h e c o i l i n shape w h ile w in d in g .

c.

Leave a 3“ l e a d o f w ir e .

d.

Wind on s i x t u r n s o f # 1 8 i n s u l a t e d w i r e .

e.

S h e lla c th e f i n i s h c o i l .

f.

Cover th e c o i l w ith a c a rd b o a rd s t r i p .

g.

W ind on 250 t u r n s o f # 3 8 e n a m e le d w i r e f o r v o l t m eter s c a le .

VANE: a.

How t o f o r m t h e t i n v a n e .

L ay o u t t h e p a t t e r n o f t h e v a n e on a s h e e t o f m e ta l.

b.

C u t o u t th e v a n e w i t h a t i n

e.

M ark t h e h o l e s i n t h e v a n e .

d.

Punch th e h o le s w ith a m e ta l punch.

e.

B en d t h e p i v o t p o r t i o n o f t h e v a n e .

INDICATOR:

sn ip s,

How t o a t t a c h t h e w i r e p o i n t e r .

a.

W rap t h e w i r e o n c e a r o u n d t h e t o p o f t h e v a n e .

b.

S o ld e r th e p o in t in p la c e .

o.

B end t h e p o i n t e r t o f i t t h e p a n e l .

CONSTRUCTION:

How t o m o u n t t h e p a r t e -

a.

F a s t e n t h e c o i l t o t h e p a n e l w i t h w ood s c r e w s .

b.

A t t a c h t h e v a n e w ith a box n a i l w i t h b e a d s a s b u sh in g s.

c.

P u t th e b in d in g p o s ts in p la c e .

d.

A tta c h t h e w ir e s to th e p o s t s .

CALIBRATION:

How t o p r e p a r e t h e s c a l e .

a.

C lu e t h e w h i t e p a p e r on th e t o p o f t h e p a n e l .

b.

C o n n e c t t h e a m m e te r t e r m i n a l s i n s e r i e s w i t h a 0 - 3 5 a m m e te r m ovem ent.

c.

C onnect th e b a t t e r i e s to

th e c i r c u i t .

d.

M ark t h e z e r o a n d tw o o r t h r e e o t h e r p o i n t s on t h e new s c a l e .

e.

D i v i d e t h e d i s t a n c e s b e tw e e n t h e m a r k i n g s e q u a l l y .

f.

Do t h e sam e f o r t h e v o l t m e t e r w i n d i n g . (1)

Hook a v o l t m e t e r i n p a r a l l e l w i t h t h e w i n d ­ in g .

(2)

M e t e r s w i l l n o t w o r k on a l t e r n a t i n g c u r r e n t .

UTILIZATION: a.

How t o m e a s u r e v o l t a g e a n d a m p e r a g e .

M e a s u re v o l t a g e b y p l a c i n g t h e m e t e r i n p a r a l l e l w i t h t h e c i r c u i t to b e m easured.

b.

D e t e r m i n e t h e a m p e ra g e o f a c i r c u i t b y c o n n e c t i n g th e m e te r in s e r i e s .

c.

M e a s u re r e s i s t a n c e b y h o o k i n g t h e m e t e r t o a

2*0 re s ista n c e in d.

(1 )

W a t t s Law:

SOURCES: a.

E = I x R.

Ohms Law:

(2) 9.

s e rie s w ith a b a tte ry ,

W = I x E.

Where t o g e t f u r t h e r a s s i s t a n c e .

B o o k s:

C raw fo rd 10- 1 8 ; G h ir a r d i 5 1 -7 2 ,

J o h n s o n 7 3 - 7 7 , 1 1 6 - 122*; J o n e s

C.

b.

F ilm s t r i p :

g.

V isits:

271- 3 2 1.

1 8-22 .

E l e c t r i c M e t e r s . Jam H andy.

P r e c i s i o n in s tr u m e n t c o m p a n ie s.

ACTIVITY ASSIGNMENTS:

P r a c tic e in th e c o n s tru c tio n o f a

m e t e r m o vem ent.

D.

1.

Make t h e a m p e ra g e m e t e r a s i n s t r u c t e d .

2.

B u i l d a n ohm m e t e r .

3.

S k e t c h t h e m e t e r movement f o r y o u r n o t e b o o k .

EVALUATION:

A p p r a is a l o f l e a r n i n g t h a t s h o u ld have de­

v e lo p e d in t h i s c h a p t e r . 1.

TRUE-FALSE:

P la c e X in th e c o r r e c t sp ace f o r tru e

or fa lse . 2.

BEST ANSWER:

P l a c e t h e num ber o f th e c o r r e c t a n sw e r

in th e p a re n th e s e s . 3.

RATING SCALE:

H ave t h e i n s t r u c t o r c h e c k a n d g r a d e

e ach of th e fo llo w in g : a.

( ) P a n e l.

b.

( ) Form.

if-1

c.

( ) C o il.

d.

( ) V an e.

e.

( ) In d ic a to r.

f.

( ) C o n stru c tio n .

g.

( ) C a lib ra tio n .

h.

( ) M e a s u r e m e n t.

(

) T o ta l.

k2

PART V.

ELECTROMAGNETISM

HOW TO MAKE ELECTROMAGNETIC APPARATUS How c a n a c o l l o f w i r e a c t a s a m a g n e t? sm a ll e le c tro m a g n e t p ic k up la r g e a u to m o b ile s?

How c a n a The a n s w e r

t o t h e s e q u e s t i o n s and o t h e r s r e g a r d i n g e le c tr o m a g n e tis m w i l l b e c l e a r a f t e r you have c o n s t r u c t e d t h e e le c tro m a g ­ n e t i c d e v i c e s t h a t a r e s u g g e s t e d I n t h e n e x t tw o c h a p t e r s .

^3 CHAPTER 9 HOW TO MAKE AH ELECTROMAGNET A.

MOTIVATION:

A d v a n t a g e s o f s t u d y i n g a n d b u i l d i n g an

e le c tro m a g n e t* 1.

CONTROL:

O b je c ts can be p ic k e d up w h ic h a re h e a v i e r

th a n t h e m agnet I t s e l f . 2.

HOBBY:

M odel t r a i n

3*

ECONOMY OP TIME:

h o i s t s c a n b e m ad e.

M a ils a n d sc re w s t h a t have s c a t ­

t e r e d on t h e f l o o r c a n b e p i c k e d u p f a s t e r . B.

DIRECTIONS:

Some o f t h e m e th o d s I n v o l v e d i n p r e p a r i n g

an e le c tr o m a g n e t. 1.

2.

BASE:

( S e e F i g u r e 9)

How t o c o n s t r u c t t h e b a s e .

a.

C u t t h e w ood t o

b.

L ay o u t a n d d r i l l t h e h o l e s .



F i l e a c h a m p h e r on t h e t o p s u r f a c e .

d.

Sandpaper a l l s u r f a c e s .

e.

S h e lla c th e b a s e .

COIL:

s iz e in a m ite r box.

How t o m ake t h e c o i l .

a.

A nneal th e screw .

b.

P l a c e t h e f i b e r w a s h e rs on t h e b o l t .

c.

W rap t h e e x p o s e d m e t a l b e t w e e n t h e w a s h e r s w i t h tap e .

d.

Leave

l e a d s on t h e w i r e s .

e.

W in d on 15 f e e t o f w i r e o n t h e s c r e w .

44 3T

V.

a. TOP v f F W

b. S IDE V/ £ W

,j x z c .

' FIGURE, ' 9 E L S C FRO M A G N E T

f . 3.

C o v er th e f i n i s h e d c o l l w i t h t a p e .

SWITCH: a.

How t o s h a p e t h e p a r t s o f t h e s w i t c h .

Lay o u t t h e p a t t e r n o n a b r a s s s h e e t .

b.

Cut o u t an d d r i l l t h e h o l e s .

c.

B en d i n t o s h a p e w i t h a p l i e r s .

k, ASSEMBLY:

How t o p l a c e t h e p a r t s o n t h e b a s e .

a.

S c r e w t h e c o i l i n p l a c e on t h e b a s e .

b.

B o lt th e sw itc h to th e b ase.

c.

P la c e th e te r m in a l screw s in th e h o le s .

d.

C onnect th e le a d s t o th e te r m in a ls and s w itc h p a rts.

5.

6.

CONNECTIONS:

How t o w i r e t h e p r o j e c t .

a.

P la c e a b a t t e r y in s e r i e s w ith th e e le c tro m a g n e t.

b.

To r e l e a s e t h e m a g n e tis m o p e n t h e s w i t c h .

APPLICATIONS:

How t o p i c k u p m e t a l .

a.

C onnect th e te r m in a l t o a b a t t e r y .

b.

P ic k up i r o n p i e c e s o r f i l i n g s .

c.

R e l e a s e t h e m a g n e ti s m b y o p e n in g t h e s w i t c h .

d.

C lo se t h e s w itc h a n d check t h e m a g n e tic

lin e s of

f o r c e w i t h a m a g n e tic com pass. 7.

SOURCES: a.

B ooks:

Where t o g e t f u r t h e r a s s i s t a n c e . C ra w fo rd 3 3 -^ 3 ; G -h lra rd i 1 1 7 -1 3 8 ; Jo h n so n

9 7 - 1 0 3 ; J o n e s ?2 - 7 5 . b. C.

F ilm s t r i p :

ACTIVITY ASSIGNMENTS:

E le c tro -m a g n e tism .

Jam Handy.

Work to do i n l e a r n i n g a b o u t

46 e le c tro m a g n e t c o n s t r u c t io n . 1.

C o m p le te t h e m a g n e t i c p r o j e c t a s s t a t e d .

2.

Make a s i m p l e e l e c t r o m a g n e t w i t h a n a i l , w i r e , a n d b a tte ry .

D.

3*

C o n s t r u c t a m odel t r a i n

4.

Draw t h e d i a g r a m o f

EVAI0ATION:

sem aphore.

th e e le c tro m a g n e t.

T e s t e t o a s c e r t a i n t h e am o u n t o f l e a r n i n g

due to t h i s w ork. 1.

TRUE-FALSE:

P la c e X in th e c o r r e c t space f o r tru e

or fa lse . 2.

BEST ANSWER:

P la c e

th e num ber o f th e c o r r e c t a n sw e r

in th e p a re n th e s e s . 3.

RATING- SCALE:

Have

th e i n s t r u c t o r ch eck andg rad e

each o f th e fo llo w in g : a.

( } B ase.

b.

( ) C o il.

c.

( ) S w itc h .

d.

( ) A s s e m b ly .

e.

( ) C o n n e c tio n s.

f.

( ) A p p lic a tio n .

(

) T o ta l.

k? CHAPTER 10 HOW TO MAKE A SIMPLE BUZZER A.

MOTIVATION:

A c c o m p l is h m e n t s e a r n e d b y l e a r n i n g how t o

c o n stru c t a b u zzer. 1.

PRIVACY:

A b u t t o n on t h e o u t s i d e o f t h e d o o r t o

y o u r ro om c a n b e w i r e d t o t h e b u z z e r w i t h i n t h e room to announce c a l l e r s . 2.

BURGLAR PROTECTION:

An e x c e l l e n t w a r n i n g d e v i c e f o r

y o u r home c a n b e made b y a t t a c h i n g t h e s a f e t y s w i t c h o f c h a p t e r 10 a n d a b a t t e r y t o t h e b u z z e r . 3.

TELEGRAPHY:

M o rse Code c an b e s e n t a n d r e c e i v e d

by h o o k in g th e b u z z e r t o a b a t t e r y a n d t e l e g r a p h key. B.

DIRECTIONS:

S te p s t o f o llo w i n b u ild in g th e p r o j e c t .

(S e e F i g u r e 10) 1.

BASE:

How t o m ake t h e b a s e .

a.

Saw t h e wood i n a m i t e r b o x .

b.

Check f o r s q u a r e s u r f a c e s w i t h a t r y s q u a r e .

c.

Mark t h e b e s t s u r f a c e a s t h e t o p .

d.

D r i l l th e h o le s w ith a body s iz e d r i l l .

e.

C o u n t e r s i n k t h e h o l e s on t h e b o t t o m o n l y .

f.

C u t t h e g r o o v e s on t h e b o t t o m w i t h a s l o y d k n i f e .

g.

F i l e o r s a n d p a p e r a c h a m p h e r on t h e t o p .

h.

S a n d a l l s u r f a c e s t o a s m o o th f i n i s h .

48

a T o p V>£W

k:

-■->)' 6 . s'/o r v / r w

*~4

t f •c.

a

#

m a t m

s

F

i g u

r e

/ o

3 f M P L S BO 2 2 PR

d

w

^

r t

.

i.

A p p ly s h e l l a c o r l a c q u e r .

SUPPORTS: a.

How t o

f o r m t h e m o u n ts .

O ut t h e t h r e e p i e c e s o f b a n d I r o n w i t h a h a c k saw .

b.

F i l e th e ends o f th e m e ta l square w ith a f i l e .

c.

B e n d m e t a l a s shown i n d r a w i n g by p l a c i n g 1/2® o f th e l e n g t h i n t o a m e ta l v i s e and b y s t r i k i n g t h e e x t e n d i n g e n d w i t h a b a l l p e e n hammer.

d.

M ark a n d c e n t e r p u n c h a l l h o l e s 1 / 4 " f r o m t h e e n d s and fro m th e s i d e s .

e.

D r i l l h o le s w ith th e p ro p er s iz e ta p d r i l l f o r 8 -3 2 sc re w s.

f.

D r i l l o n e h o l e i n t h e l o n g e r s i d e o f o n l y one o f th e su p p o rts f o r a 1 /4 -2 0 ta p and th e o th e r s w i t h th e 8 -3 2 t a p .

COIL:

How t o make t h e c o i l .

a.

A n n e a l a 2" 1 / 4 - 2 0 ,

i r o n , R .H .M .S .

b.

S c re w on two f i b e r w a s h e r s a b o u t 1 1 / 4 " a p a r t .

c.

W rap t h e e x p o s e d m e t a l b e t w e e n t h e w a s h e r s w i t h ta p e .

d.

W ind on 15 f e e t o f No. 22 D .C .O . m a g n e t i c w i r e . (1)

L ea v e a 4" l e a d a t t h e b e g i n n i n g a n d a t t h e end o f th e w in d in g .

(2)

Be s u r e t o w i n d t h e c o i l i n o n l y one d i r e c ­ tio n .

e.

Cover th e f i n i s h e d c o i l w i t h t a p e .

ARMATURE: a.

How t o s h a p e t h e a r m a t u r e .

C u t a s t r i p o f 20 g a u g e s h e e t i r o n o r t i n w i t h a tin

sn ip .

b.

C u t a s t r i p o f 2k g a u g e b r a s s .

c.

S o l d e r t h e b r a s s a n d i r o n s t r i p s a s shown i n d ra w in g .

d.

C e n te rp u n c h th e h o le i n t h e end o f t h e a rm a tu r e .

e.

D r i l l a b ody h o l e f o r a n 8 - 3 2 s c r e w .

CONSTRUCTION: a.

How t o a s s e m b l e t h e p a r t s .

M ount t h e s u p p o r t s o n t h e b a s e w i t h l “ 8 - 3 2 serew s. (1)

P la c e th e s h o r te r s id e o f su p p o rt a g a in s t th e b ase.

(2 )

F ile

o f f t h e e n d s o f t h e s c r e w so t h a t t h e y

a r e f l a t w i t h s u r f a c e of th e s u p p o r ts . b.

S c re w t h e c o i l i n t o p l a c e a s i l l u s t r a t e d . (1)

F ile

th e th re a d e d end f l a t w ith th e su p p o rt.

(2)

F ile

t h e head o f th e screw u n t i l th e s l o t

i s gone a n d i t lo o k s l i k e a b u t t o n . c.

d.

F a s t e n t h e a r m a t u r e t o t h e s u p p o r t a s show n. (1 )

P la c e t h e ir o n s u r f a c e to w ard th e c o i l .

(2)

F i l e o f f th e en d o f th e

P la c e an 8-32

screw .

screw i n th e r e m a in in g s u p p o r t a s

an a d j u s t a b l e c o n t a c t screw .

51 (1)

F i l e a p o i n t on t h e t h r e a d e d e n d o f t h e screw .

(2)

P l a c e tw o n u t s on t h e h e a d s i d e o f t h e s u p ­ p o r t a s a lo c k in g d e v ic e .

e.

U se two s c r e w s a n d tw o n u t s on e a c h o f t h e screw s to s e rv e a s b in d in g p o s ts .

6.

WIRING-: a*

How t o c o n n e c t t h e p a r t s e l e c t r i c a l l y .

T h rea d th e c o l l l e a d s th ro u g h t h e h o l e s i n th e b a s e t o t h e g r o o v e s on t h e b o t t o m s i d e . (1)

Have t h e w i r e f o l l o w t h e g r o o v e s t o t h e screw h e a d s .

(2)

L o o se n t h e s c r e w s a n d p l a c e t h e b a r e p o r t i o n o f th e w ir e u n d e r th e screw h ead in a c lo c k ­ w ise d i r e c t i o n .

(3)

T ig h te n screw s w i t h a s c r e w d r iv e r and c l i p o f f e x t r a w ire w ith a d ia g o n a l p l i e r s .

b.

C onnect th e o t h e r te r m in a l p o s t an d a rm a tu re s u p p o rt w ith an e x t r a p ie c e o f w ire -

c.

C onnect a b a t t e r y to th e te r m in a l sc rew s.

d.

A d ju s t th e c o n ta c t screw and th e

a rm a tu re u n t i l

th e b u zzer o p e ra te s . 7.

OPERATION: a.

How t o h o o k y o u r b u z z e r i n c i r c u i t s .

Connect a b a t t e r y , b u t to n , and y o u r b u z z e r in s e r i e s t o make a c a l l

b.

sy ste m .

W ire y o u r b u z z e r i n p a r a l l e l w i t h a n o t h e r b u z z e r .

52 c. 8.

A t t a c h tw o b u t t o n s a n d two b u z z e r s .

SOURCES: a.

Where t o

B ooks:

get fu rth e r a ssista n c e .

C raw ford 5 2 -5 6 ; G h i r a r d i 1 1 7 -1 3 8 ; Joh n so n

1 0 2 -1 1 4 ; J o n e s 318-319b. C.

F ilm s t r i p :

E le c tro -M a g n e tism .

ACTIVITY ASSIGNMENTS:

Jam Handy.

Some .lobs f o r e x p e r i e n c e i n e l e c ­

tro m a g n e tic d e v ic e s .

D.

1.

Make t h e b u z z e r a s d i r e c t e d .

2.

B u i l d a b u z z e r o f y o u r own d e s i g n .

3.

D e sig n a r e l a y .

4.

C o n stru c t an a n n u n c ia to r.

5.

Draw t h e b u z z e r ,

EVALUATION:

c o m p lete w i t h t h e p a r t s and w ir in g .

Q u e s tio n s to t e s t th e l e a r n i n g from t h i s

c h a p te r. 1.

TRUE-FALSE:

P la c e X in th e c o r r e c t s p a c e f o r t r u e

or fa lse . T a.

( )(

F ) W i r e s h a v e to b e p l a c e d u n d e r t h e s c r e w h ead s I n a c lo c k w ise d i r e c t i o n .

b.

( )(

) I r o n p o r t i o n o f t h e a r m a t u r e s h o u l d be p l a c e d to w a rd t h e c o i l .

2.

BEST ANSWER:

P l a c e t h e num ber o f th e b e s t an sw er

in th e p a re n th e se s. a.

{ ) The c o r e o f t h e c o l l h a s t o b e :

( l ) M ag n etized .

(2 ) A n n e a le d . b.

( 3 ) T e m p e re d . ( 4 ) P a i n t e d ,

( ) The o o l l o f t h e b u z z e r s h o u l d h a v e : sm a ll l e a d .

( 2 ) No l e a d s .

(l)

( 3 ) Two 4" l e a d s .

( 4 ) T h r e e 3® l e a d p . RATING- SCALE:

P la c e X in th e space f o r p a r t s o f

th e b u z z e r t h a t m eet th e s p e c i f i c a t i o n s e x a c tl y . a.

( ) B ase.

b.

( ) S u p p o rts.

c.

( ) C o il.



( ) A rm atu re .

e.

< ) C o n stru c tio n .

f.

( ) W irin g .

g.

( ) O p e ra tio n .

(

) T o ta l.

One

54-

PART V I .

CIRCUIT WIRING-

HOW TO MAKE CIRCUIT CONTROL DEVICES How a r e l i g h t s c o n t r o l l e d I n t h e home?

How c a n l i g h t s

b e made t o I l l u m i n a t e l e s s a n d l e s s u n t i l t h e y a r e o u t ? T h e s e q u e s t i o n s a n d o t h e r s r e g a r d i n g c i r c u i t w i r i n g a n d co n ­ t r o l w i l l b e a n s w e r e d w hen y o u c o n s t r u c t t h e d e v i c e s i n t h e n e x t tw o c h a p t e r s .

55 CHAPTER 1 1 HOW TO MAKE A SAFETY SWITCH A.

MOTIVATION:

B e n e f i t s d e r i v e d f r o m t h l a l e s s o n on t h e

b u ild in g o f a s a fe ty sw itc h * 1.

BUROLAR PROTECTION: a l i g h t > b u zzer,

T h is d e v ic e can be w i r e d w i t h

o r b e l l to

I n d ic a te th e ap p ro ach

of a b u rg la r. 2.

PRIVACY:

The s w i t c h can

y o u r room t o w a rn y o u I f 3-.

TIME:

be a tta c h e d to t h e d o o r o f som eone I s c o m in g .

The s w i t c h c a n a c t a s a n a u t o m a t i c c o n t r o l

d e v i c e t o o p e n a g a r a g e d o o r w hen B.

DIRECTIONS:

2.

BASE:

up.

S u g g e s t i o n w h i c h w i l l a i d I n th e m ak in g o f

th e s a f e t y s w itc h . 1.

a c a rd riv e s

( S e e F i g u r e 11)

How t o p r e p a r e t h e b a s e .

a.

C u t t h e wood t o s i z e .

b.

L ay o u t a n d d r i l l t h e h o l e s .

c.

Cut th e g ro o v e s i n th e b o tto m s u r f a c e .

d.

F i l e a cham pher on th e

e.

Sandpaper and s h e lla c a l l s u rfa c e s .

CONTACT:

to p s u rfa c e .

How t o s h a p e t h e m e t a l s t r i p .

a.

L ay o u t t h e b r a s s a r m a t u r e .

b.

Cut t o

siz e w ith a t in n e r ’s sn ip s.

c.

L o c a te and d r i l l

th e

d.

B en d t o s h a p e w i t h a

h o le s. p lie rs .

s& r

i.ii M f

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