View
224
Download
1
Category
Preview:
Citation preview
8/20/2019 Fun Electronics Projects for the Experimenter (1)
1/189
r
ths
illu|EII
F-
F d
6 1 1
8/20/2019 Fun Electronics Projects for the Experimenter (1)
2/189
rurProlcGB
lr tln
hoilmomtl
During
more han
20
years,
he author,
s
a
collaborator
ithAmerican,
European
ndLatin
Americanlectronics
agazines*,
as
published
large
assortment
f
practical
ircuits sing
ommon
arts.
Nowmany f those
projects
re ncluded
n thisvolume,mostof
which
ou
canbuild
n
one
evening.
he
projects
angerom un ypes hrough
ractical
types
o amusement
ypes.Of course,
hereareotherdevices
hatcan be
used o
teach
ou
something
bout ircuits r components.
An mportant
eature
f
heses
rojects
re
he deaso
Explore,ntended
or
students
ooking
or
projects
n
science r
o use n
practical
esearch.
We
can
considerhisbook
as a source ookof
theeasiest nd
un-to-make
of he
hundredsf
projects
reated nd
published
y
heauthor uring
hese
last
years.
But,as
the
projects
re
n a wide
angeof types,
we
should eparate
he
electronics
xperimenters
nto wo
groups:
heones
whowant o
improve r
expand
omeotherarea
of theirelectronics
nterest, uchas
computers,
radio,nstrumentation,
udio, ecurity nd
even
games;
nd
he ones
who
want o
learn omethingbout
electronicircuits nd
devices r
want
new
ideaso
use
n science
rojects.
Most f heprojectsescribedereinanbestand-alones ndividualcces-
sories;
herever
ossible
he
circuits
ave een esigned
o hat
hey
an
be
ganged
ithoneor
more ther
rojects.
orexample,
any
rojects
f audio
etfects r
generators
anbe
ganged
ith
audio mplifiers
r
high-powerut-
put
stages.
All
he
projects
resimple,
ith
ew ow-cost
omponents
hatcan
be
maden
oneevening f
work.
Tomake t easy or he readero chooseheprojects eadded odes fter
each
itle o ndicatehe
kind
of
experimenterfor
homheyare
ntended:he
code
P
(Practical)
ndicates
project
uilt or
practical
se.
Thecode
E'
(Experimental)
ndicateshat he
project
s intended
or
heexperimenter
o
teach omethingbout
ircuits r devlces.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
3/189
trolrcc
Of course,
ou
can
also
ind
projects
with
both codes
E
and P)which
an
dther
be mounted
o teach
something
rknd
be used or
a
practical
nd.
The
presentations
f the
projects
re
practical.
lectronics
omponents
re
listed
with
each
circuitdiagram.
ut
secondary
arts
such
as sockets,
has-
sis,enclosures, iscellaneousardware nd so on, are not
specified, ince
the reader
s
free o
choose hesenon-critical
tems
according
o
his
prefer-
ences
and demands.
The
manner n
which he
circuitswork
and
can be modifieds
explainedn
practical
erms
so the reader
an
acquire
ome
knowledge
f
practical
lec-
tronics
as he
progresses
hrough
he book.
Although
many
of the
projects
we
enjoyed
onstructing
s heyaredescribed
here, oumay hinkof possiblemodifications.e ustrecommendhatyougo
aheadand modify
he circuits
o
yourpersonal
nds.There s
a
wide
atitude
in
circuitmodifications
nd
most
of
them
will
be of
value
o
the experimente
who
wants
o see how
hingswork,
even hough
each
project's rimary
ntent
is or
he
builder
who
desires functional
tem
of equipment
s he
result
f his
work.
As
the
book
ncludes
asy-to-build
rojects,
he
authorhopes t
will help
you
to learn
many
of the undamentals
f electronicsn
an
easyand
un
way,
and,
if you'rea student, rovide source orschoolprojects.
Newton
C.
Braga
.
Mini-Projects
s
he itle
of a column
ublished
y heauthor
uring evera
years
n
a
Brazilian
lectronics
agazine
amedEletr6nicaTotal
Total
Elec-
tronics).
8/20/2019 Fun Electronics Projects for the Experimenter (1)
4/189
frnFdocahlhclnulmtmol
MlcRo-PowER
EDFLASHER
E/P)
A simple
LED lasher
an be built
witha TLC7555 imerusedas a low-
frequencyscillator
nd
drive o an
LED.
C1 uns n a
low requencyeter-
mined y
R?R3andC1.
Frequencys n he
ange etween.1
and5
Hz
but
you
canalter
t bychanging l.This
capacitor
an
angerom
1
to
10uF.
Duty ycle
sdeterminedy
R2/R3
atio
nd
s mportant
napplications
here
you
need eductionf
energy onsumed.Though
igure shows
ixed
esis-
tors
or R2
and
R3,
you
can
use rimmer
otentiometers
f
youprefer.
he
potentiometers,fcourse, rehandyoralteringhe
requencyndduty
ycle
of theoscillator.
Rl values epend
pon
he
power
upply
oltage.
With
power
upplies
e-
tween
and6
volts,R1
s 470
ohms.
With
power
upplies
etween
and9
volts,
Rl is
560
or
680
ohms.
With
power
upplies
n he ange etween
and
12volts,
l must e
1,000
hms.The
ircuit rains nly
50uA
rom 6-vol
power
upply.
Figure
showsheschematic
iagram
or
he
Micro-Power
ED
Flasher. t
the
heart f hecircuit
s Ol,
a 555
imer.
Use
he
partsplacement
iagram s
a
guide
whenassembling
he
Micro-
Power ED
Flasher. omponents
lacement,
sing
terminal trip
as chas-
sis,
s shown
n Figure
2.
Take pecial are
with
positions
f
polarized
omponents,
uchas
the
LED
andelectrolytic
apacitor.
After ouaresure hatyouhavewiredall hecomponentsorrectly,ut he
batteries
n
hebattery
older. heLEDshould
lash.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
5/189
R1
560s,
c1
4.7pF
Dl
Rg
1N914
4KT
Figure
I
H. lGt t@
l {
Figure
2
8/20/2019 Fun Electronics Projects for the Experimenter (1)
6/189
mtnfffifrtchrmlffi
PartsList
-
Micro-Power
EDFlasher
lC1
-
TLC7555CMOS
ntegrated
ircuit
Timer
LEDI - Commoned,greenor yellowLED
D1
-
1N914
general
urpose
ilicon iode
Rl
-
560
ohm,
114W,5%
esistor
R2
-
1,000,000hm,
114W,5%
esistor
Rg
-
4,700ohm,
114W,5%esistor
C1 - 4,7 uF,6 M/DCelectrolyticapacitor
C2
-
10
UF,
2
W\/DC
electrolytic
apacitor
81
-
6
to 12VAA cells,9V
batteryor
power
supply
ldeas o
Explore
learnmoreabout
he circuitand devices:
o
AlterR2and
R3
(minimum
alues
re
1,000 hms
or
both)
andsee
how he
lashing atechanges.Of course,
f
you
want,
you
can
replace
R2
and
R3 with
1,000,000-ohmrimmer
potentiometers.
o Explain ow he astable 55works n this circuit.
o
Alter
C1
n a
rangebetween and
100
uF and
observe
lashing
ate
alteration.
xplainwhat
happens.
o
What
s
duty-cycle?
8/20/2019 Fun Electronics Projects for the Experimenter (1)
7/189
FroFGtl
lmPomrlMmficr
Science
xperiments
ith
he clrcuit:
o
LED
s
a monochromatic
ight
source.You
can
perform
ome
ex-
periments
n
optics
using hiskind
of light
source.
Chromatic
ilters
an
be used n
some
experiments
nvolving
EDs.Tryto
se
LEDs
of differ-
entcolors red,yellow, reenand, f possible, lue).
.
Light lashes,
s the
ones
produced
y this
circuit,
an be
used n
hypnotic
xperiments.
o
The
circuit
can
be used
o indicate
operation
f
otherelectroni
devices.
Wired
o
the
power
supply
of
a
monitored
evice,
he
blinker
LEDwill
ndicate
ts
operation.
Rememberhat he heoryn hisbook sspecificallyelatedo theassociated
experiments
nd
projects.This
ook s
designed
s an ntroduction,
ot
as an
in-depth
reatment
f electronics.
f
you
are interested
n
finding
out more
about he
subjects
ouched
on
in
this
book,
several
exts
can
be
found
or
further
eading.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
8/189
frnPrrre$hrfiosrrhdlu
SET-RESET
LIP-FLOP
E)
With
his
pQect
we can
show
how
wo
NAND
ates
f a
7400
C
(TTL
nte-
grated
Gircuit)
an
be
wired
o
perform
s an
R-S
lip-flop.
This ircuit
sa
pulse-triggeredlip-flop
hat
needs
egative-going
ulses
o
be
triggered.
his
circuit
perates
s
follows:
s
we see,
t haltwg_outngls;
nolmd
output
alled
(LED1)
nd
an
nverted
utput
alled
(LED2).Whe
one
output
s 1 he
other
ecessarily
illbe0 and
ice-versa
ecause
heyare
complementary.
Thecircuit
asalso
wo
nputs
amed
(SET)
nd
R
(RESET)
s shown
n
theschematic
iagram,
here
he
rigger
ignals
re
applied.
R nput
s
wired
o
Q
output
nd
S
nput
s
wired
o
Ooutput,
orming
closed
loop
or hedigital
ignals.
When
negative-going
rigger
ulse
sapplied
o S
nput
heoutputQ
swingi
to the
1 staie.
As histutput
s wired
o
R nput,
he
1 state
auses
utput
Q
to
all o a 0
evel.
ut
Q
output
s
also
wired
o S
nput ausing
feedbackth
makes
tsoutput
emain
t
1
also
atter
he rigger
ulse
asdisappeared.
o
trigger
he
lip-flop
gain,
hanging
he
output
tates,
eshould
pply
nega
p -goingpulseoR nput.Thisulse ausesheoutputogo o1 andas his
output
s
wired
o R
nput,
he rigger
ulse
lso
causes
he
outputQ
to
go
o
0level.
Azero
n this
output
oes
o
R input,
ndalso
after
he
rigger
ulse
isap
pears
heoutputs
emain
n their
states.
See
hat
he circuit
as
wo stable
tates,
nd
we
only
can
change
hese
states
withset
or
reset
S
or
R) negative-going
ulses
pplied
o
its nputs.
Our
project
s a
manually-triggered
lip-flopndcanbeconstructediring
switch
o
the
R-S
nputs s
shown
n Figure
1.
Logic
tates
re
ndicateqby
wo
LEDs.
ED1
lows
witha
1
at
Q
output
nd
LED2
lows
with
a
1
at
d
outPut.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
9/189
Ffd0crz
sH-i$fff,llHrr
The
circuitmust
be
powered
y
a S-voltegulated
ower
upply
s t
usesa
TTL
C.
Currentequirements
ange
ypically
rom
5 to
15
mA.
Components
lacement
n
a small
rinted-circuit
oards
shownn
Figure
.
Experimentsike hiscanalsobeperformednwhatelectronicsxperimen
erscall
breadboards".
These
reboards
n
which
he
parts
of experiment
can
be emporarily
ssembled.
y
using
readboards
t is
notnecessary
o
teo\/7
$1"
t'\tt
ffin
Figure
I
Figure
2
r8
8/20/2019 Fun Electronics Projects for the Experimenter (1)
10/189
Frndrctrffithe halmffil
solder
he
components.
his
s
why hey
are
also
called
solderless
boards"
The
circuit
an
be
used
o
teach
much
about
lip-flops,
sed
n computers
s
counters
nd
n
memories
nd
many
other
applications.
Observation:n digitalelectronics n electrical ignal s eitherhighor low.
These
wostates
ale
used
o
represent
inary
bits
1
and
0.
Since
digital
ogic
lOs operate
rom a
single-ended
ower
supply,
a
high state
represents
voltage
ear
he supply
oltage
nd
a
lowstate
epresents
voltage
ear
0V'
Panrs
Lsr
-
SET-RESET
UP-FIoP
fC1
-
74OO
TL
Integrated
ircuit
LEDs - Red,greenoryellow ommon EDs
R1,
R2
-
330
ohm,
114W,5Y"
esistors
51
-
SPDT
toggle
switch
ldeas
o
ExPlore
To
earn
more
about
he
circuit
nd
devices:
o
The
common
lip-flop
s
a
fundamental
ounter
ircuit.
Mount
ther
units
ike
his
and
use
hem
o explain
owcounters
nd
memorie
work
n computer
ircuits.
ach
lip-flop
an
store
a
bit.
.
Find
he
ditferences
etween
-S
and
J-K
lip-flops
nd
how
hey
are
used
n
ogic
ircuits.
Science
xperiments
nd
projects
sing
his
circuit:
o
Replace
1
by
a-magnetic
reed)
witch
r a
microswitch
nd
use
thiscircuit
s
a one-event
emory
n experiments.
t can
detect
nd
memorize
hen
a Switch
n an
ure,
alarm,
r
mechanical
rocess
s
closed
ora
moment.
-
tf
8/20/2019 Fun Electronics Projects for the Experimenter (1)
11/189
Hn
ProfmBf
ilo lrnulmrnml
MIN|-METRONOME
P)
Heresa dandywo-transistoretronomehich oucanbuildntoa sma
plastic
ase.
You
can
usean old
nonworkingransistor
adio o
house his
gadget.
n mostcase
you
can
merely emovehe
main
circuitry
ut
retai
some
parts,
uch
as the on-otf
olume ontrol
otentiometer,
peaker nd
battery
older.
f
you
havedone his,
you
have
ust
eliminated
he ollowin
items:
PKR,
1,and
81.
Thecircuit anbe
powered
ith woorfourAA ells
nddrains bout
0mA
Assoonas 31 isclosed,hemetronorfletbrtq lacking.yadjustingoten
tiometer
1
you
ind he
beat'or
frequencyf clacking
ou
wish o set.
Tocalibrate,
ou
have nly
o synchronize
our
metronome
itha commerc
type
or any
known ource.
Figure
shows
he
schematic
iagram
or
he
Mini-Metronome.
t he
hea
of
thecircuit re
Q1
and
Q2,
as a
two-stageirect-coupled
mplifier,
hic
allows
hecircuit
o
generate
ntervalled
ulses.
Figure
2showsa
mechanicalviewf
themetronome,
sing
terminal tri
as
chassis
for hesmall
omponents.
Position f
the
polarized
omponents,
uchas Gl, C2
and
he transisto
should e
observed
n hemounting.
rt
8/20/2019 Fun Electronics Projects for the Experimenter (1)
12/189
;fdcr8
ilrl-IrEwm
Q1
R1
10K
*_J
Q 2
| s t \
Bc5s8
| t
t l
c 2 d
I
100pF
T I
I t ?
l a r :
|
3/6V
T-
SPKR
4l8A
+ r \
c1
lOpF
R2
1 K
P1
1 M
Ftgure
1
Figure
2
\
t0
8/20/2019 Fun Electronics Projects for the Experimenter (1)
13/189
HftFCIFfrilTtrlffiHT
-
- --
Parts
List
-
Mini
Metronome
Q1
-
8C548
NPN
ransistor
Q2 - 8C558 PNP ransistor
51
-
SPST
toggle
or slide
switch
81
-
3V
or 6V
-
two or
four
AA cells
SPKR
4 or I
ohm,
2
to
4-inch
oudspeaker
P1
-
1,000,000
hm
Potentiometer
Rl
-
10,000
hm,
1l4W,5olo
esistor
PA
-
1,000
hm,
114W,5%
esistor
C1
-
10
pf,
6
VVVDC
lectrolytic
apacitor
C2
-
10
Uf,
6
WVDC
electrolytic
apacitor
ldeas
o
ExPlore
To
earn
more
about
he
circuit
and
devices
r
to
get
better
performance:
o
Replace
1
by any
capacitor
n
the
range
etween
and
10
pF
Observe
hat
will
happen
o the
beat
ate.
Explain
t'
o
Replace
ransistor
2
withaTlP32
on
a small
eatsink
nd
powe
thecircuit
rom
a 9V
or
12V
power
upply.You'll
ave
extra
ower
or
your
experimental
etronome
nd
can
use
t
in
arger
laces.
o
.
Remove
Pl
and
ouch
with
your
ingers
he
points
where
t
was
wiied.
Will
he
circuit
perate?
an
you
explain
hat
s
going
n?
-
2a
8/20/2019 Fun Electronics Projects for the Experimenter (1)
14/189
Prtlm8
thl-ilrtrrnrm
Science xperiments
nd
ditferent
ses or he
circuit:
o
The
metronome
an
be used n
gymnastic
xercises
r
n
running
to find
he
correct
hythm.
hemetronome
an
be
housed
n
a smal
plastic
ox,
powered
ycells
andeasily
arried ith
he unner.
o
Biological
xperimentsith
sounds
an
be
made
with his
device
experimentsn
animal
onditioning,or
example.
n
8/20/2019 Fun Electronics Projects for the Experimenter (1)
15/189
filnH.f0c03ffisrhoilm
PENDULUM
LARM
(E/P)
Any
movement
hat
swings
he
pendulum
ensor
riggers
his
alarm,
nabling
a
relay.
Thecircuit
an
be
used
o
protect
ars,
arge bjects,
omes
nd
other
laces
as
he
sensor
an
be used
o detect
ny
movement.
hisdevice
an
alsobe
used
orscientific
xperiments,
s suggested
t
theend
of
thesection.
The
relay
andrive
powerful
ound
ystems,
uch
as sirens,
orns,
amps,
etc.
Thecircuit
an
be
powered
y
a
l2-voltbattery
when
used
n
cars,
or
instance)
r
a
power
upply.
urrent
rain
s
very ow
about
00
uA)
when
he
relay
s
deenergized,
xtending
attery
ife.
Theschematic
ircult
f
he
Pendulum
larmsshown
n Figure
.Thecircuit
hasas
its
heartan SCR
Silicon
ontrolled
ectifier),
hich
energizes
he
relay
when
he
sensor
etects
ny
movement.
A mechanical
iewof
thecircuit
mounting,
sing
terminal
tripas
chassis,
is shown
n Figure
2.
Relay oil
voltage
s chosen
ccording
o the
power
upply
oltage.
ou an
usea miniDPDT AMiniRelayRadio hack 75'249)r, orheavyoads,
10AminiSPDT
elay
Radio
hack
75-248).These
elays re
rated
o
12
VDC
and drain
only
38
mA
(their
oil
resistance
s about
320
ohms).
As
equivalent
ypes an
be
used,
ou
should
akecare
with erminal
ayout.
Reset an
be
made
witha
momentary-typ6
witch
Push-On)
ired
etween
theSCR
anode
ndcatode,
r by
using
heon-otf
witch.
Positions
f
polarized
omponents,
uch
as
the SCR
and
diode,
hould
e
::t::r :tairs
are
atso
iven
n Fisurc2.
Norice
hatoperation
ccurs
hen
the
vertical
or
horizontal)
are
wire
ouches
he
ringduring
ny
movement
2l
8/20/2019 Fun Electronics Projects for the Experimenter (1)
16/189
fl0l0c|
Penilulumlhrm
(sEE
TEXT)
X1
R1
scR
Ttc106
Figure
I
Figure
2
'B
8/20/2019 Fun Electronics Projects for the Experimenter (1)
17/189
m'lrfrctstrhrhuffim
PartsList
-
Pendulum larm
SCR
-TlC106
requivalent
ilicon
ontrolled
ectifier
D1
-
1N914 requivalent
eneral-purpose
ilicon iode
K1
-
12V elay
see
ext)
S1
-
SPST
lideor
oggle witch
Rl
-
22,OOOhm,
114W,5%
esistor
R2
-
10,000 hm,
114W,5%
esistor
X1 - Pendulumensorsee ext)
ldeas o
Explore
To earnmoreabout
ircuit nddevices:
o
Replace
elay
with
a
12Y
200mA ncandescent
amp.Does
he
circuitwork?
o
Explain hat
Dl
is
doing
n hiscircuit.
s
t necessary
f he elay
s
replacedyan
ncandescent
amp?
o
Explain
owanSCR
works
Science
rojects
nd
ditferent ses
or hiscircuit:
o
Replace
1 by a
reed
switch
o
get
an alarm
riggered y
a
mag-
netic ensor.Youanalso eplace 1bf a microswitchr other indof
momentary
witch.
o
In
biological
xperiments
he alarmcan
be used
o detect
mal
movements
n animal
rapsor cages.
t0
8/20/2019 Fun Electronics Projects for the Experimenter (1)
18/189
Frfhct
?oildumllrrm
o
Replacing
l
by wo
metal
wires
enables
he
circuit
o
be riggered
by water.
Water
evel
detectors
an
be made
using
his kind
of
sensor,
and t
can
be used n
many
experiments
nd
practical
pplications.
o
lnstalled
n
your
car, his
circuit
an
be used
as an
alarm,
driving
hehornor a siren.
o
By replacing
1
with
a
large
metal
plate,
he
circuit
an
be used
o
detect
wind.
Air
low
can
move
he
plate
so
that
he
bare
wire
ouching
the loop
causes
he
alarm o
trigger.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
19/189
runPnFctlollhEnul
MEDIUM-WAVE
F
PRESELECTOR
P)
The
sensivity
f
most
moderately-priced
M
eceivers
s
poor
n he
medium-
wave
and.
orse
yet,
selectivity
lso
drops
tf
sharply
ithin
he
upper
art
or
tn"
band,
making
ne
receiv-er
ighly
usceptible
o
images,
oise
and
annoying
eterodYnes.
Even
he
best
antenna
nd
a
good
booster
mplifier
an't
make
p
or
hese
deficiencies
n
a common
eceive/s
ront
end.
But,
using
n
RF
preselector
b;trd;
the
antenna
nd
he
eceiver's
ntenna
nput
erminals
ill
give
ou
realncreasen hereceptionuality.
This
ircuit
matches
he
antenna
mpedance
ith
he
eceive/s
ntenna
nput
according
he
requency
f
the
uned
tation'
Figure
shows
chematic
iagram
f
the
Medium-wave
reselector'
Figure2
shows
n
exploded
iew
of
the
circuit,
which
an
be
housed
n a
small
lastic
ox.
Ll
is
ormed
y
urns
f
No.28
enameledire,wound na 5/16-incherrite
form.
aps
re
made
ach
15
or
20
urns
and
ts
number
s not
critical'
he
number
f
taPs
an
be
altered.
Attach
our
antenna
nd
ground
o
the
nput
erminals
f
the
preselector
Tune
o
the
desired
tation
n
your
eceiver,
nd,
by
choosing
he
best.posi-
tion
of
the
alligator
lip
on
he
trip
anO
y
adjusting
V
find
he
best
signal'
The equired
ntenna
ill
depend
pon
he
station
ou
want
o
tune'
A
ran-
dom
ength
f
wiie
willgive airlygoodperformancehroughheA{ band'
Antennas
ith
engths
-etween
s
ano
150
eet
are
ecommended
or
best
performance.
-
tf
8/20/2019 Fun Electronics Projects for the Experimenter (1)
20/189
Filf0cr
5 tdhmtmtrlffiffir
A
G
To
Receiver
Figure
I
Figure
2
{
el
g l
8/20/2019 Fun Electronics Projects for the Experimenter (1)
21/189
HrfilFcNrtrffisuhM
- - - -
Parts
List
-
Medium-Wave
F
Preselector
L1
CV
X1
-
Medium-Wave
oil
-
see
ext
-
365
pF
miniature
ariable
apacitor
-
Alligator
lip
-
2-position
arrier
triP
ldeas o ExPlore
To
earn
more
about
he
circuit
nd
devices:
o
Explain
he
mportance
f
a
good
ground
onnection
n hiscircu
What
s he
meaning
f
"impedance"?
o
Use
a
newcoil
with
20
urnsand
apsevery
turns
o
tuneshor
wavestations.
o
Make
seoond
oil
20
urns)
n
hesame
errite
od o
plug
h
antenna
nd
ground.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
22/189
ftnFillectiffimmlhleilcr
ELECTRONIC
ISHING
URE
(P)
This
circuit
mitates
he
sound
f
wet
bugs
milling
bout
he
surface
o attra
curious
ish.
The
circuit
s basically
Hartley
udio
oscillator
perating
n
a
frequen
between
00
and
2,006
Hertz.
Powered
y
an
AA
cell,
t can
housed
n a
clea
empty
eanut
utter
ar
with
he
buzzer
ircuitry
mounted
pside-down
n
h
.ofti.Vou
must
be
carefull
ot
o
drill
n such
a
way
as
o
allow
water
o
ea
tnrougn
he
cap.
ilicon
ubber
an
be
used
o
close
ny
water
eak'
CapacitorCl
ould
ive resonantfrequencyof
pproximately
,000
Hz'
b
p1
would
ive
a
wid6
ariation
n
signaltone
enerated
n
he
audio
ange
You
an
also
use
a
low-impedance
arphone
s
a
transducer,
onnecting
t
the
second
oil
output) f
the
ransformer'
To
operate,
nscrew
he
cap,
hrow
S1
ON,
put
he
cover
ack
on,
and
dr
the
ish
ure
nto
he
water
n ne
vicinity
f
where
ou
will
be
ishing'
llow
minuteseforeeelinghemn. f necessary,diustP1 oa new
signal
on
Figure
I shows
he schematic
iagral
for
the
Fish
Lure.
observe
hat
h
se-condary
oil
of
the
small
udio
ransformer
s
not
used
n
his
circuit.
construction
etails
f
the
Electronic
ishing
ure,
sing
terminal
trip
chassis,
s shown
n
Figute
2.
The
exact
ocations
f
components
s
n
critical.
T1 salsonotcritical.ny500:8
r
1,000:8
ransistor
ransformer
ith
en
tapped
rimary
an
be
used.
we
canalsosuggesthatanysmallransi
transformer
an
be
experimented
ith'
EO
8/20/2019 Fun Electronics Projects for the Experimenter (1)
23/189
Pnm
0
$oe[cnhHshlnf
un
S1
1.5V
(')
SEETEXT
R1
1 K
Figure
1
Figure
2
It
8/20/2019 Fun Electronics Projects for the Experimenter (1)
24/189
Fr}Idccufor[nHrcilmEmGl
PartsList
Electronic ishingLure
Q1
-
8C548
general-purpose
PN
silicon
ransistor
T1
-
500:8or 1,000:8ransistor
ransformer
(RadioShack2TS-1380s suitableor his ask)
P1
-
100,000
hm
rimmer
otentiometer
R1
-
1,000
hm,
114W,5%esistor
C1
-
0.01uF
metal ilm
or ceramic
apacitor
S1
-
SPST
oggle
r slide witch
BZ - Piezoelectricransducer r crystalearphone
(Radio
hack273-073r equivalent)
81
-
1.5V AA
cell
ldeas
o
Explore
To earnmore
about
he
circuit:
o
ReplaceBZby
a
low-impedance
weeter r small oudspeakeron-
nected o the transformer econdary
oil.
o
ChangeC1
values n
the range
between .001and0.22uF.
Ob-
servewhat hapenswith one
pitch.
A higher-value
apacitor
ives
a
lower one.
o
The circuitalso
operates
rom
a
3V
or
6V
power
supply
without
making
nychanges.
ft
8/20/2019 Fun Electronics Projects for the Experimenter (1)
25/189
Plolocl
HGGtorlcHrillululc
Science nd ditferent
ses
or
he
device:
o
You
anmake everalexperiments
nanimalconditioning,ncluding
the
ones
hat ive n the water. ry
o
alter
he RC network
P1,
R1 and
Cl) to
get
onesof ditferent
itch.
ry o usediodes, mall ransformer
coils
and other
passive
omponentsn this
experiment.
ounds
ike
those
produced
ysongbirds anbe
generated
ith
a
few
components
arranged n the
correct
way.
Can
you
discover
how
o do
it?
o
Removehe
piezoelectric
ransducer
nd
wire
electrodes
n ts
place.
The
device an be useas a nervstimulator. xperiments
ithanimals
and
plants
can be made.What
physiological
unctions
re atfected?
Can
circadian hytms
r
internal
iological
locksbe atfected y con-
tinuousexposureo sounds?
o
Electrodes
laced
ntowater
and wired n
place
of the transducer
will
produce
current ield.You an
pedorm
nteresting
cientific
ork
relating ow ish
andother
Water
eings eact o the
current
ield.
Can
the current ieldsaffect
physiological
unctions?f
you
experiment
ith
plants,
elect
a
fast
growing
ouse
plant.
80
8/20/2019 Fun Electronics Projects for the Experimenter (1)
26/189
ftn
rdccEhr[tcHnilmms
FREE-POWER
M
RECEIVER
RE)
Thisprojectusesa strangeway o get ts power.t usespower extracted
from
he uned
tation
o
give
o
the amplifier
ransistor.
itha
reasonably
strong
pplied
modulation
nvelope,
his
ypeof detector
roduces
strong
demodulated
utput.
Naturally,
he
closer
ou
are
o a strong
tation,
he
more urrent
our
adio
willbe
able
o supply.
For
best
esults,
ou
must
oeverything
ossible
o deliver
strong
ignalto
the ransistoretector. erecommendgoodantennandground,he at-
ter
preferably
eing
madeo a
water
ipe
or solid
xternal
round
omposed
of a
pipe
driven
t
east
feet
ntomoist
arth.
his
s mportant
orensuring
maximum
ignal
ickup.
I
lf
you
have
lenty
f space
vailable,
he
ongerheantenna
up
o about
00
feet),
hebetter
he
results.
Figure
shows
he schematic
iagram
f the
Free-Power
M
receiver.
b-
servehat heheartof thecircuitsa germaniumransistorhatworks sa
detector
ndaudio
mplifier.
Gomponents
lacement
n a
terminal
tripused
as
a chassis
s shown
n
Figurc
2.The erminal
trip
anbe
ixed nanexperiment
oard
hatcanbe
constructed
sing
ome ommon
ools
and
materials.
Ql
isany
germanium
ransistor,
uch
s
GE-2 r
2N107.You
an
ind
germa-
nium ransistors
n
old
nonworking
M ransistor
adio
eceivers.
onworking
AM radios analsosupplyhevariable apacitornd he oopstickferrite
rod).
Earphone
ust e
a
high-impedance
rystaltype.
ow-impedance
arphones
don't
unction
n hiscircuit.
_
8/20/2019 Fun Electronics Projects for the Experimenter (1)
27/189
Pnffi
r Foailrmlilrsrffi
Figure
I
s - 4 ^ o
Figurc
2
t8
8/20/2019 Fun Electronics Projects for the Experimenter (1)
28/189
frn?nfffihrucmlffi
--
Parts
List
-
Free-Power
M
Receiver
Q1
-
NPN
or
PNP
germanium
ransistor
see
ext
XTAL- Crystal arPhone
L1
-
LooPstick
see
ext
CV
-
365
pF
variable
apacitor
see
ext
Rl
-
12,000
hm,
114W,57
esistor
C1
-
1 uF,
25
WVDC
lectrolytic
apacitor
ldeas
o
ExPlore
To
earn
more
bout
hecircuit:
o
Replace
l by
15
urns
of
No.
28
wire,
wound
n
a
ferrite
od,
o
tune
short'wave
tations.
o By eplacing l withagermaniumiode nd emoving1andC1
you'litransform
his
adio
nto
a simple
rystal
et'
o
Alter
R1
n a
range
etween
,7}Oand
7,000
hms
o
get
better
performance,epending
n
he
ransistor
sed'
o
Replace
he
ransistor
itha
silicon
ype,
uch
s
he
8C548'
What
will
haPPen
ithsensivitY?
science rojectnvolvinghecircuit nd,uncommonses:
o
Explain
ow
rystal
ets
unction
nd
ellabout
adio
istory.
f
you
are
nterested
n
more
adio
istory
everal
exts
an
be
ound
n
the
public
ibrarY.
o
lf
you
want
o
earn
more
bout
adio
eceivers,
ry
o
ind
nforma
tion
about
eterodyne
nd
super-hereterodyne
ypes'
-
tl
8/20/2019 Fun Electronics Projects for the Experimenter (1)
29/189
HEFfdffiffnrffilmrbl
DUAL-LED
LASHER
E,P)
Thiscircuit
sesa
one-gate
scillator,
itha
4093
CMOS
G,
o
produce
50%
duty-cycle
lasher
n two
LEDsor a bi-color
ED. he circuit
an
be
poweredya 3 to 12-voltower upply nd s usefulnseveral xperiments
and
practical
pplications.You
anuse
t as
part
of alarms,
arning ystems,
games,
oys, ndsome
cientific
xperiments,
s
wewilldescribe
ere'
R2and
R3
values epend
pon
he
power
upply
oltage, ccording
o the
following
able:
Power Supply
3 Volts
5
Volts
6
Volts
9
Volts
12
Volts
R2, R3
220ohms
330 ohms
470 ohms
820
ohms
1,000 hms
Formore utput oucanusea transistorizedutput tage rivingncandes-
cent
amps.
Experiments
o observe
ightetfects n animals
nd
plants
an
beconducted
ith hiscircuit.
Pl andC1
determine
lash ate.
Flash
ate
can
be adiusted
y
P1,butCl
also
canbe
altered
n a
large ange f
values,
ccording
o theapplication
you
ntend
or hedevice.
Schematic
iagram
or he
Dual-Led
lasher
s
shown
n Figure
1.
One
gate
of a 4093C s usedasoscillatornd heotherwoareusedas nverters.
Components
lacement
n a
PCboard
s
shown
n
Figure2.You
analso
usea
breadboard
r solderless
oard
o mount
t
as an
experimental
ircuit.
Positionf
he
polarized
ieces,
uchas
LEDs, letrolytics
nd
C,should
e
observed.
tf
8/20/2019 Fun Electronics Projects for the Experimenter (1)
30/189
,,
trmAl
ld.|nm*ol
P1
R1
tM
100K
cl
1pF
(.)
SEE
TEXT
- - - t ,
z ' i
I
, l
- . \-,
\-_
LEDl
Figure
1
t{
+ 3 a
12V
ov
c1
3 E
n D r
Figure
2
ft
8/20/2019 Fun Electronics Projects for the Experimenter (1)
31/189
Iun
Plolects
ol thc
Dttrcfimcntot
Parts
List
Dual-Led
lasher
lC1
-
40938CMOS
ntegrated
ircuit
LED1
-
bi-color
r
red
and
green
ommon
EDs
(RadioShack276-012l
R1
-
100,000
hm,
114W,5%
esistor
R2,3
-
resistor ccording
o
power
supply
oltage see
ext
P1
-
1,000,000 hm
potentiometer
C1
-
1
uF,
25
WVDCelectrolytic
apacitor
ldeas
o Explore
To
earn
moreabout
he circuit
nd
devices:
o
ReplaceC1
with capacitors
n the
rangebetween
1 and
47 uF.
Observe owhigher aluesalter heflash ate.
o
Infrared
EDs an
be used
n
some
experiments.
ochange
n he
original
ircuit
s necessary.
Science
nd
different
ses
or he
circuit:
o
Remove
P1 and
R1 and
wireat this
pont
a
touch
sensor
r elec-
trodes.
oucan
control
he
flash
ateby
touch.
A
bio-feedback
evice
canbe made hiswaY.
o
By wiring
he
lC s
pin
1 to an
external
ircuit,
he
flasher
an be
controlled
y a
logic
evel.CMOS
circuits
an
be used
o control
he
flasher.
il
8/20/2019 Fun Electronics Projects for the Experimenter (1)
32/189
,
,
Pnml
mu+nnm
o
Mount
he
LEDs
n
place
f he
enses
,
.ffi
flash
ate
an
be
adjusted
o make
n
hypnotic
r
relaxingLtfect.
om
bine
his
with
a
touch
ensor
nd
you
have
n
uncommon
io-fee
back
evice.You
an
also
use
his
circuit
o make
xperiments
n
circa
dian hythms r internal iologicallocks, eterminingow heycan
be
altered
y ight
pulses.
arious
heories
ave
een
proposed
bou
this
subject.
.
Psychiatrists
re
using
phototherapy
o help
some
patients.
an
you
ind
some
application
or
he
circuitn
his
ield?
.
Pl
also
an
bereplaced
y
resistive
ransducers,
uch
as LDRs
r
NTCs,
o
give
a light-
r emperature-dependent
lash-rate
ircuit.
x
periments
anbe madewithconductivityf materialsyconnectin
probes
n
series
with
R1.
Replace
l
with
he
probes
n
his
case.
g l
8/20/2019 Fun Electronics Projects for the Experimenter (1)
33/189
IunProfcctsorstGrDcIlmGntGl
6V
X 1A POWER
UPPLY
P)
Inorder operform xperimentsndprojectsnvolving lectricityouwillneed
a sourceof
voltage. oltage equirements
or
common
projects,
uchas the
ones
n
hisbook, epend
pon heirapplications,
nd
typicallyange rom
a
few milliamperes
o one or two amperes.
lnstead
f usinga battery
ou
can usea circuit alleda
power
supply.
The
power
supply
we
show
here
can be used o
provide
V
x 1A regulated
output
o
the experimentalnd
practical
ircuitsdescribedn this
book.
The
outputvoltage s fixedby the lC.
Figure
shows he schematic
iagram
or
his
power
upply.Ol is a voltage
regufator,7806.
The
"06"
indicates
hat
t is
a
6-volt
egulator.
Figure2
shows
he
componentsayout, sing
a
terminal
tripas chassis.
The
complete
roject
an be assembled
n
a small
plastic
ox.
The ntegrated
circuit hould e
mounted
n a heatsink. ou
canalsoaddan LED n series
witha 470ohm resistor, ired n theoutputof the circuit o indicatehat t is
on.
External ircuits
an be connectedo the
power
supply
with
alligator lips.
Position f the
polarized ieces,
uch
as diodes,
he lC,
and electrolytica-
pacitors,
must
be observed.
The ransformersn't
a critical
art
of
this
project.
ypes
with
a
secondary
oil
rangingrom
7.5 to 12 volts
and currents etween
00
mA
and
14
can be
used.
5f
8/20/2019 Fun Electronics Projects for the Experimenter (1)
34/189
trolrct
g
8u
ll
Pil0tsuillr
D2
1N4002
c2
100pF
tl_
T
I
I
=
T1
12
+
'l2Y
1 A
lou
c1
1000pF
Figure
I
Fiaure
2
t
55
8/20/2019 Fun Electronics Projects for the Experimenter (1)
35/189
mFrtmctrtrtrHilffi
PartsList
-
6-Volt
Power
Supply
lOl
-
7806
positive
hree-terminalegulator
T1
-
Transformer:
rimary
17VAC
seconda
y
12+12Y 1A
D1,2
-
50V
x 1A 1N4002
r
equivalentilicon
ectifier
iodes
C1
-
1,000
F,25WVDC
lectrolytic
apacitor
C2
-
10
uF,
12WVDC
lectrolytic
apacitor
S1
-
SPST witch
ldeas
o Explore
To
earn
moreabout he
circuit r alter he
performance:
o
ReplaceC1
bya 7805, 809
or
7812
f
you
want
a 5V 9Vor 12V
power
supply. oumayalsohave o change he transformer itha
117:15+1
Vusing 7812.
.
Explain ow
he
circuit
works.
o
What s the
ditference etween
n AC
and
a DC
current?
Science nduncommon
pplications:
o
This
power
upply an
be used
n
chemical
xperiments,uch
as
theones hat nvolve urrentlow hrough ubstances.xperiments
involving
lectrolysis
ndelectroplating
re wo hat
canbesuggested.
A variable ound-wire
otentiometer
100
ohms, watts) hould e
wiredn
series ith he
power
upply utputo imit
urrentlow hrough
the
oad.You
an
alsouse heLightDimmer
escribedn his
book
or
this ask.
a
8/20/2019 Fun Electronics Projects for the Experimenter (1)
36/189
Plrflct
g
0u
r
lt Pilil $utilr
o
6V
200
mA small
ncandescent
amps an be supported
y
this
power
upply.
hese
amps re excellent
ightsources
o
work
with
microscopes.
o
Small
motors
nd
ampsnexperiments
nvolving
hysics,
echan-
icsand oboticsanbepoweredrom hispower upplywithadvan-
tages.
ou
don't
have o spend
lot
of
money n
cellsor
batteries.
o
All
circuits
escribed
n hisbook
which
equire 6V
supply
anbe
powered
y
his
power
upply.
o
Thecircuit
anbe
usedas an
excellent
ower
dapter
or
youi
6V
equipment,
uch
as small
adios,
alculators,
tc.
o 6V amps anbe usedn experimentsnvolvinglantgrowth. e-
lecta
fast
growing
ouse
lant
nd
use.a arkroom
r
cardboard
ox
to coverthem.
amps
ith
olored
ilters an
beused
nanexperimen
involving
rowth
nd
development.
o
Circadian
hythms an
also
be studied
singanimals
r
plants.
Lamps an
be
powered
n
at
night
nd
otfat
day.
What
physiologica
functions
ould
beatfected?
5t
8/20/2019 Fun Electronics Projects for the Experimenter (1)
37/189
mFilncNsfffirHrufinrm
rNsEcT
REPELLENTP)
Some ontinuousoundsan epelnsectsandalsoattract).he requency
and ntensity
epends
pon he
application
nd ype
of insect
nd
can be
found
hrough
xperimentation.
The
circuit
hown ere
generates
continuous
ound
hat
canbe
used o
repel
or
attract)
ome
ypes
f
nsects,
r n
scientific
xperiments
nvolving
animals.
Our nsect
epellent
an
be
powered
y9V
batteries,wo
M
cellsor our
AA
cells,and ts owcurrent equirementsillextendhe ifeof those ellsor
batteries.
Figure
showshe
schematic
iagram
f
the nsect
Repellent.
heheart
f
thecircuits
a 7555 C,
a
CMOS
imerwired
s
anaudio
scillator
nddriving
a
piezoelectric
ransducer.
The
components
lacement
na homemade
rinted-circuit
oards
shownn
Figure
2.
Exact
placement
s not
hat
critical.
All he
components
nd he
power
upply an
behoused
n
a small
lastic
ox.
Transducer
Z
s
a crystal
arpiece
ra
piezoelectric
ransducer,
uch s he
Radio
hack 73-073.
Position
f the
polarized
ieces,
uch
as
c2 and he
power
upply,must
be
carefully
bserved.
Using he nsect
epellent
s very
easy. ou
onlyneed
o
adjusthe
rimmer
potentiometer
1 o
produce
soundwith hesamepitchas the nsect ouintend
o
repel.
xperimentation
hould
emade
ntilyouind
he
best ound
to repel
specificnsect.
60
8/20/2019 Fun Electronics Projects for the Experimenter (1)
38/189
E
led
l0
In$octidhm
R2
4K7
cl0.047p.F
Figure
1
Figure
2
01
8/20/2019 Fun Electronics Projects for the Experimenter (1)
39/189
ftrF||f|Gilthlhsuh |m
Parts
List
-
Insect
Repellent
c1
BZ
R1
R2
P1
c1
c2
S1
B1
-
TLC7555
MOSntegrated-circuit
imer
-
Crystal
r
piezoelectric
ransducer
RadioShack 73-073r equivalent
-
10,000
hm,114W,5%
esistor
-
4,700
hm,114W,5%
esistor
-
100,000
hm rimmer
otentiometer
-
0.047
F metal
ilm
or
ceramic
apacitor
- 10uF,12WVDC lectrolyticapacitor
-
SPST lide
or dggle
witch
-
3V
(2
AA
cells),
V
(4
M
cells),
V
(battery)
ldeas
o Explore
To
earn
more
about
he
circuit
r
get
better
erformance:
.
Powerful
utput
anbe
obtained
ith
a transistorized
utput
tage
as shown
n Figure
3.
The
power
ransistor
hould
e mounted
n
a
heatsink.The
ransducer
s
a ow-impedance
oudspeaker
:anging
rom
4
to
8 ohms.
o
Experiments
ith
ultrasound
ah
be made
with
his
circuit:educe
Cl to 1200
F
anduse
a
piezoelectric
weeters ransducer.emovethesmall
ransformer
sed
n hese
weeters
nd
plug
he
ransduce
directly
o the
circuit
utput.
utputsn
requencies
s high
as40,000
Hz
can
be
produced
y his
circuit.
o
Explain
ow
sounds
an
be
produced
y
electronic
ransducer
suchas
he
oneused n
his
project.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
40/189
?nhd
l0 InrstirDdhnt
o
Whatareultrasounds?
Science
ndditferent
pplications:
a
Of
course,
ou
can est
he realetfects f
this deviceon
several
kinds f nsects. n attractiveiologicalxperimentanbeconducted
based n
hiscircuit.
o
Etfects f sounds n
plantgrowth
r development
an be
con-
ducted sing
hiscircuit.Can
sounds
qr
ultrasounds)
lter hecirca-
dian
hythms f
plants
nd
nsects?
o
The
continuous
one
produced
y
hiscircuit anbe
used
n
alarms
or
warning ystems.
ice
and
other mallanimals
re
repelled y
powerfulltrasounds.
o
Replace
2byan
LDR.Theircuit
ow
becomes
light-dependen
oscillator.
xperiments
ith ightandsounds an
nowbe conducted
using
hedevice.
6 to 12V
Figure 3
08
8/20/2019 Fun Electronics Projects for the Experimenter (1)
41/189
HnPnlmts||]mHlo|lmeml
ULTRASONIC
ENERATOR
E/P)
Dogs,
mice, ats
and
other
nimals
an
hear ounds
ith
requencies
p
o
4O,O0O
z.
There re
several
inds f
insects
hat
canalso
hearor
react
o
thesesounds. he circuitwe propose ereproduces continuousound
emission
n frequencies
bove
he
human
imit,or a
range etween
8,000
and
40,000
Hz.
These ounds
re
called
ultrasounds
nd
can
be used
n
several
xperimental
nd
practical
pplications.
The
device
edescribe
ere
anbe
used
o scare
ogs nd
other
nimals,
n
biological
xperiments,
nd
many ther
nterestingpplications.
The
recommended
iezoelectric
ransducer
as
ts maximum
utput
owe
between 00 and 3,000Hz, but t alsowill operate t higherrequencie
emitting
ess
power.
The
ecommended
ower
upply
s ourM cells
or a
9-volt
attery.
Our
project
unsbetween
pproximately
8,000
nd
40,000
Hz,but
you
can
easily
lter
his
ange ychanging
1,
n a
range etween
70
pF
and0.001
uF.
Frequency
anbe
setby
P1
n he
range etermined
y C1.
Rememberhat he40938C willoscillaten requenciesp o 500kHz.
The
complete
ircuit
f
the Ultrasonic
enerator,
sing
he
our
gates
of a
40938
ntegrated
ircuit,
s shown
n Figute
1.
Components
lacement
n a
printed-circuit
oard
s shown
n Figurc
2.
Thecircuit
an
be
housed
n a small
plastic
ox
and
he ransducer
illbe
fixed
n he
ront
panel.
Take are
with he
position f thepolarizedarts, uchas thetransisto
electrolytic
apacitor
nd
power
upply.
Forcontinuous
peration, 1
should
e
mounted
n a
heatsink'
The ransformer
s nota critical
art.
Any ransformer
itha
secondary
oil
ranging
rom
100 o 500
mAcan
be
used
n his
project.
-
00
8/20/2019 Fun Electronics Projects for the Experimenter (1)
42/189
F.lect l
uftmmlcecmntu
Figure I
Figure 2
0t
8/20/2019 Fun Electronics Projects for the Experimenter (1)
43/189
HiFrrN.Gt3ffimmdlmrfit]
PartsList
-
Ultrasonic
Generator
lC1
-
40938
CMOS
ntegratedircuit
Ql
-
8D135medium-powerPN iliconransistor
BZ
-
Piezoelectricransducer
RadioShack
73-090
r
equivalent
Tl
-
Transformer:
rimary
17VAC;
econdaryVx100
mA
R1
-
10,000
hm,
114W,5%
esistor
R2
-
1,000
hm,
114W,5%esistor
Pl - 100,000hm rimmerotentiometer
C1
-
4,700
F
ceramic r
metalilmcapacitor
C2
-
100
uF,
12 M/DC
electrolyticapacitor
S1
-
SPSToggle r slide witch
81
-
6V
or 9V
-
AA
cellsor battery see
ext
ldeas o Explore
To earnmoreabouthecircuit r
o
get
better
erformance:
o
You
an
eplacehe
piezoelectric
ransducerya common
weeter.
Remove
1
and
BZ
and
place
he weeter
etween 1
and
Ql's
col-
lector.Can
you
measurehe
generated
ltrasound
ower?
.
Thecircuit analso
generate
ound
n
heaudible
ange. eplace
Cl bya
capacitor
n
he
ange
etween .02and0.1uF.
o
Explain ltrasoundsnd
how hey
re
produced
yelectronic
rans-
ducers.
0l
8/20/2019 Fun Electronics Projects for the Experimenter (1)
44/189
P'rhct tt
Uhffuh8emn0r
o
What s
a
piezoelectric
aterial?
Science ndditferent
pplications:
o
Several xperiments
anbe made
sing ltrasounds.
ou
anex-
periment ithdogconditioning.singhisoscillatoroucancalla dog
using n
naudible
ound
inaudible
o humans)
o
Ghoose capacitor
etween
.01and
0.047 F o
produce
ounds
both n
the audio ange
nd
ultrasoundange. ou
an
now
conduct
experimentso
determinehe
exactupper-limit
requency eard
by
humans.You
lso anconduct
xperimentsith
animals.
t
willbe m-
portant
o have frequency
ounter n hand
o do hiswork.
o Replace Zbyelectrodes.hecircuitwillgenerate high-voltage
outputhatcan
beused
n
nerve
timulation.
se
a 10,000
hm
poten-
tiometer
o
adjust utput oltage
t his
point.
ulses
an
each
eaks
as high
as
400
volts.
o
To
get pulses
for
nerve
timulation
nd otherexperiments)
ou
onlyhaveo replace
1with
a
1
uFcapacitor
ndP1with
a
1,000,000
ohm
potentiometer.
ulses
n he rate
ange
etween
.1
per
second
to 10
per
second anbe
generated
ith his
change.
o
This
ircuit analso
beused s
a
fluorescent
ampnverter.
com-
mon luorescent
amp
4
to 20 wafts) n
place
of the ransducer ill
glow,
ven
one hat
s
weak
enougho not unction
n
heAC
power
line.
00
8/20/2019 Fun Electronics Projects for the Experimenter (1)
45/189
Hr PnhG[slorl[c
ilmmt
DC
LAMP
DIMMER
E,P)
Thiscircuit
an
be
used
o controlthe
mount
f
current
n an
ncandescent
lamp
andalso
a
DC
motor.
f
you
change
heamount
f
current
hrough
lampyouchangets brightness.nd f youchangehe amount f current
through
DC
motor
ou
change
tsspeed.
nput
oltage
an
ange
rom
6 to
12
voltsand
current
rain
n the
output
s
up
to
2A.
Youcan
also
use
his
circuit
n the output
f
a 6V
or
12V
ixed
power
upply,
onverting
t intoa
variable
to 6
voltor
0
to
12voltsupply.
The
power
ransistor
hould
e
mounted
n
a
heatsink.
hecircuit
an
be
housed
n
a
small
lastic
ox
and
he
heatsink
ith
he ransistor
ixed
n
the
outside.
Thecircuit
an
be used
o control
rightness
f
a car's
panel
amps nd
n
robotics
o control
DC
motor peed
long
wide
ange
f
values.
lso,
ev-
eral
experiments
nvolving
urrent
low
control
an
be
performed
sing
his
circuit.
Thecircuit
cts
as
a
variable
esistor
r
rheostat
ith he
principal
urrent
flowing
hrough
he
ransistor
nd
he
control urrent
lowing
hrough
he
po-
tentiometer.
urrent
hrough
he
potentiometer
s onlya
few
milliamperes.
The
schematic
iagram
f
the
DC dimmer
s shown
n Figurc
t.
Ql
is an
NPN
power
ransistor
nd
he
principal
omponent
sed
n this
project.
Components
ayout
s shown
n Figure
2.
Thetransistor
oes
not show
on
the
heatsink,
owever.
Equivalent
ransistors
an
be used,
ut
akecare
with
he
maximum
urrent
they
can control.
ypes uch
as
TlP31and
TlP41
can be
used
o control
lampsup to 2 amperes. lso,a furthermodificationn Rl valuemustbe
made
o
ensure
hat,
when
P1
s set
near
ts minimum
alue,
hatcurrent
s
flowing
hrough
he
amP.
lf
equivalent
ransistors
re
used,
ake
care
with
heir
erminal
ositions,
s
theycan
be
ditferent.
-
AD
8/20/2019 Fun Electronics Projects for the Experimenter (1)
46/189
Prrfoct
2 DG
mr Iilmmu
Figure
I
F1
5A
Q1
2N3055
+12V
IN
oul
I
:
Figure
2
t3
8/20/2019 Fun Electronics Projects for the Experimenter (1)
47/189
Hr]||Fc0tffimDculmffir
PartsList
-
DCLampDimmer
Q1
P1
R1
F1
-
2N3055 Silicon
NPN
power
ransistor
- 4,700ohmpotentiometer
-
470
ohm,
2W,.5 /
esistor
-
5A
fuse
ldeas o Explore
To earnmore bout
hecircuit r
to
get
better
erformance:
o
Youcanusea
PNP
power
ransistor,
nvertingnput
polarization
Explain
hy hiscircuit anonly
controlDCcurrents.
o
A Darlington
ransistoranbeused
o reduce urrent
low hrough
the
potentiometer.
eplace 1witha 100,000 hm
common
otenti-
ometer
nd Rl
with
a
10,000 hm,
1/4watt esistor
hen
using
a
Darlington
ower
ransistor.
lPl10canbe used
n hiscase.
o
What s a rheostat?
Science
nduncommonpplications:
o
Youcan use
his
circuit
o control rightness
f microscope
ight
sources. 6V
ampcanbe used
or hat ask
and
hiscircuit
willbe
wired
between
he
amp
and
a 6V
power
upply.
he 6V
regulated
power
upply escribed
n his
book
s deal
or his
application.
o
Experiments
n
electrolysisnd
electroplatinganbe
current-flow
controlledy using
hiscircuit.
a
Thiscircuit anbe used o
control mall
motorsn robotics r
in
physics
xperiments.
tl
8/20/2019 Fun Electronics Projects for the Experimenter (1)
48/189
ffi|m n
mllmDllmmei
o
The
amountof current
n
current ieldscan
be controlled y using
this
circuitand a
DC
power
supply.Experimentsnvolving
lectrotro-
pism
can be attempted. ry o
put plants
within
a coil
o
observe
he
influence
f
the magneticield
on their
growth
and
development.
e-
member
hat there
s
a magnetic ield
arounda coil of
wire
that
is
carrying current.
Figure3
showshow his experiment
an be arranged.
The
coil
s formed
by 10 to
50
turns
of common
No.1
to 22wirearounda
cardboard oxor wood orm.An
ammeter
n
series
with
he coilcircuit anbe
used o control he amount
of currentused
n
the experiment.
Remember
hat too much
current
will
cause he coil and the transistoro
overheat.t is a good dea o add a lamp n serieswith he coil circuit. he
lampwill
add resistanceo the coil
circuit,
educing
urrent
low
to a safe
level.
Figure
3
t5
8/20/2019 Fun Electronics Projects for the Experimenter (1)
49/189
Iun
Piilcctsfuh
scilmmu
AUDrOOSCILLATOR
E)
This ow-powerxperimental
scillatoran
generate
udible
ignals
n
the
range etween
00and
2,000Hz,driving
small
oudspeakerr
a low-im-
pedance
arphone.
hecircuit an
be
powered
y2 twoor
our
AA
cells
or a
fixed6
volt
power
upply.
urrent
equirements
or hiscircuit
epend
pon
the
power
upply
oltage nd he
oudspeaker
mpedancend
range ypi-
cally
rom
10
o 300
mA.
Potentiometer
1 adjusts
he operating
requencynd
can be set
within
large ange f values. otentiometersp o 1,000,000hmscanbe used,
changing
he requency
ange
owerimit
o
about
10
Hz.
C1
can
alsobealtered,
nd
values etween.01
andO.22uF
resuitable
or
experimentation.
argeC1
values
ill
produce
requencies
n he ower
art
of
he
ange.
Thecircuit an
be usedas
part
of alarms,
ames,
oysand o
learn
more
about
ransistorized
scillators.
Figure
shows
heschematic
iagram
f theAudio-Oscillator.1
and
Q2
forma directed-coupled
mplifiernd
Rl/Cl is heclosed
oop hat
akeshe
signal ack
rom heoutput
o the
nput.
.
,
Figure2shows
he
ayout
f
hecomponents,
sing
terminal tripas
chas-
sis.
All hecomponents
nd
power
upply
anbe
housedn a small
plastic
box.
Thekeysatelegraph
omemade-typewitch,
utyou an
alsousean
SPST
toggle r
slide witch
orcontinuous
peration.
key
s recommended
f
you
want o use
heoscillator
sa
Morse
Code
ender
n demonstrations
r
prac-
tice.
Youcan
wire he
points
A and
B to the contacts f
a relay
o use he
circuit s
part
of an alarm.
tt
8/20/2019 Fun Electronics Projects for the Experimenter (1)
50/189
Pf.lcct 8 ftllrosoilrt|l
cl
0.047pF
B1
3TO 6V
Figure
I
k-\
Figure2
t0
8/20/2019 Fun Electronics Projects for the Experimenter (1)
51/189
mFmf0cilsffmHrulmdu
PartsList
-
Audio
Oscillator
Q1
-
8C548
eneral urpose
PN
ransistor
Q2
-
8C558 eneral
urpose
NP ransistor
SPKR 4
or 8 ohmsmall
oudspeaker
K
-
Telegraphic
ey
See ext
81
-
3
to
6
volts two
or ourAA
cells
Ri
-
10,000 hm,114w,5 esistor
R2 - 1,000 hm,114W,5 esistor
Cl
-
0.047 F
metalilm
or ceramic
apacitor
ldeas o Explore
To earnmore
bout hecircuit r o
get
better
erformance:
o
Change
1
or
a capacitor
n
he ange
etween
.01
and
0.22uF.
The
requencyange
f the
produced
one
will
be
altered.
With
0.01
uF
or
lower aluesor
Cl,
thecircuitwill
produce
ltrasounds.sea
tweeter
r a
piezoelectric
ransducer
n his
case.
.
Replace
1
with
a
TlP32
orTlP42
nd
poqer
hecircuitwith
a
12
volt
supply.You'll
et
muchmore
power
n he
output.
.
Explainwhy
oscillators eeda closedoop o thesignalo work.
Science
rojects
ndother pplications:
o
Experimentsn
acoustics
anbe
made
with his
device.
he
circuit
can
produce
ny one
between
0
and20,000Hz,
andeven igher.
tt
8/20/2019 Fun Electronics Projects for the Experimenter (1)
52/189
;nlrcr l3
|latr
Iscffia.]
o
A telegraph
tation
anbe simulated ith
his
circuit.
ou
an
ind
Morse
Code
n
anybook
about elegraphy.
o
By eplacing with
a reed
wichwiredo
points
and
B, he
circuit
willoperates an alarm.
o
Experiments
nvolving
onductivity
f
materials
anbe
made
with
probes
lugged
o
points
and
B.
o
Connectesistive
ransducers
s LDRs ndNTCs
t
points
and
B to
get
a
light-dependent
r emperature-dependent
scillator.
a
Using
wo metal
ods
as sensors,he
circuit an
be useas a
lie
detector r bio-feedback
evice. eplace
l
with
a 0.22or 0.47
uF
capacitorndadjustPl to getseparatedulses
t the
speaker.
he
pulse
atewill
bealtered hen he
skin
onductivityf he nterrogated
person
hanges
hile
n
a stateof strain
ue o a lieor
stress.
o
A 117V+V x 250mA
ransformer
an eplace
PKR o
produce
high-voltage
ulses
n nerve
timulation
xperiments.
he
generated
pulses
an
each
oltages
s
high
as 400Vpp.
o
Experimentsn
animal
hysiology
an
beconducted
sing ounds
or highvoltage s describednotherprojects. rowth f plants ub-
mitted
o high-power
ounds
r
high-voltage
ields
an be observed
using
hiscircuitwith
practical
xperiments.
o
AC ields
anbe
generated
y
eplacing
he
speaker itha 2O-turn
coil.
The
plants
r animals
anbe
positioned
ithin
hecoil's
lectric
field.
See hesame
experiment
singheDCDimmeror
coiland
ex-
periment
etails.
tl
8/20/2019 Fun Electronics Projects for the Experimenter (1)
53/189
IunPnfmtrfimH|Oilmmr
AUDIO
SWTTCH
E/P)
Thisaudio ontrolledelay asa large umber f applicationsnd
s nterest-
ing o he
experimenter
howisheso
explore
heworking
niversef
relays
andaudio r sound ontrolledircuits.
An
audio
ignaln he
amplitude
ange etween Vppand
5
Vpp riggershe
relay,
owering
n
he
device,
ired
etween
oints
and
B.
Relay alues determinedy
power
upply oltage. ora 12volt
power
up-
plyyou
must
usea
12volt elay.
urrent
rain
epends
pon he
power
up-
ply
voltage
ndalso he
elay
sed.Using 12Y
x
38
mA
Radio
hack
75-
248'1relay,hecurrent rains owenougho allowheuseof commonells
n
thepower upply.
Cl
can
ange
etween.01and1.0uF,anddetermineshesensitivityf
he
circuit
n he
audio
ange. arge alues
ive
more
ensitivity
t ow
requen-
cies.
Thiscircuit
as
a
high-impedancenput
and
needs
strong udio ignal
o
operate.
Figure showsheschematiciagram f heAudioSwitch. bservehat he
heart f hecircuits a common
eneral-purpose
PN ransistorhatactsas
a
DCamplifier.
ln
Figure
2we show
ayout
f components
or
his
project.
he
components
canbesolderedna terminaltripused schassis.Theerminaltrip anbe
flxed n a wooden oard.
Positionf the
polarized
omponents,uchas hediodes,
ower
upply nd
capacitor 2,mustbeobserved.
To
use hisaudio
elay
ou
have
o
wire
ponts
A
and
B
to the output
f an
audioamplifier
minimum
ower
equireds
5
watts) ndadjusthe
volume
control
or
bestoperation.
A
small
ransistor
utput
ransformer
hould eused
o
operate
he elay
with
low-impedanceignals,uchas heones
rom
heoutput f audio mplifiers.
8/20/2019 Fun Electronics Projects for the Experimenter (1)
54/189
Fofeot f
lullr ilftGn
D2
1 N 9 1 4
D1
R1
1N914
, t0K
(.)
sEE
TEXT
B1
6 O R 9 V
Figure I
Figure 2
05
8/20/2019 Fun Electronics Projects for the Experimenter (1)
55/189
mrilffi||rrhsll|mmr
Figure
3
shows
how
o use his ransformer.
R,depends n
he
output
ower
f
the
amplifiernd
s
given
elow:
Output
Power
0
to 1 watt
1
to
10watts
10
o 25
watts
25to50watts
I
47
ohms,
1/4watt
100
ohms,' l l4watI
220ohms,ll2watt
PartsList
-
Audio
Switch
Q1
-
8C548
general-purpose
PNsilicon ransistor
D1
-
1N914
eneral-purpose
ilicon iode
D2
-
1N4002
ilicon
ectifier iode
Kl
-
6V
or 12V
relay
see ext
R1
-
10,000
hm,
1/4W,5% esistor
Cl
-
metal ilm
or ceramic
apacitor
see
ext
C2
-
100 uF,12WVDCelectrolytic
apacitor
81
-
6V or
12V
cells,
power
supplyor battery
t0
8/20/2019 Fun Electronics Projects for the Experimenter (1)
56/189
;TrM
lf rilm nilH
ldeas
o Explore
To earn
more
about hecircuit
nd
devices
r o
get
better
erformance:
o
Replace
l
with
a
Darlington
ransistor
such
as a BCS17)ndresistor
1 with100,000
hms. he
circuitwill ncrease
n
sensitivity.
o
Explain
ow
C1 unctionsn
his
circuit.
Science nd
different
pplications:
o
Connecthe
circuito
anaudio mplifier
utput, ith
a mioophone
plugged
o the
amplifiernput.You'll
ave
sound-operated
witch.
o Thiscircuitwitha microphonendanaudio mplifieranbeused
to close
a trap with
sound
activation
r
to
activate recording
ith
sounds.
You
can alsouse t
to
photograph
n
explosion
r the crash
of an
object
y riggering flash
with
he
produced
ound.
o
The
audio
output f
a
multimedia
ystemn
a computeran
be
used o
control
xternal evices ith
his
circuit.
R;
l-----+x
FRoM
IIF
ro
AMPLTFTER
3lE
AUDlos\
ourPUT
|
' ' l
L._--_-{'Y
8 :
1000
o
Figure
3
tt
8/20/2019 Fun Electronics Projects for the Experimenter (1)
57/189
IunPnlos lol UrG nilmomcr
6
VOLTSFROM12V
BATTERTES
P)
With hisadapter oucanpower6 volt up o 1A)devices, uchas recorders,
CD
players,
alculators,adios, attery
hargers, tc., rom
your
car battery.
The
currentadapter s
plugged
nto the vehicle ighter
socketand is small
enough
o
be
housed n
a verycompact
lastic
box.
Only
our
components
re used.
The
lC determines
he outputvoltage
and
shouldbe mounted
n a
heatsink.
apacitors re
polarized
omponents,o
you
must
observeheir
position
whenmounting.The
use s very mportant
n
order o
protect
he
deviceand car wiring
against horts.
Output ariesaccordingo the
device
ou
are
applying
ower
o. DC
exten-
sioncableswith
plugs
o fit the
device o be
powered
houldbe used.Take
care with the
output
poles.
Check
f
your
devicehas a
positive
r
negative
pole
n the
centralerminal.
The
schematic iagram
f the
12V
o
6V
x 1A
converter
s
shown n Figure 1.
The
principal
omponent
s lC1,
a
6V
voltage egulator
hat
operates
with
input
voltages angingrom
to
35
volts.
Componentsayout s
shown
n
Figure 2. All
he components
an easilybe
housed
n a
plastic
box.
The ntegrated
ircuit an be changedo alter he
output oltage.Youan use
a
7809
or
9V
x 1A
output r a
7805
or
5V
x 1A
output.
It is very mportant
hat no
parts
of the components
sed
n
thiscircuit ouch
one another. he lC has
short-circuit
nd
hermal
protection.
t
8/20/2019 Fun Electronics Projects for the Experimenter (1)
58/189
?nhcr 5
olrilsFmlzummilis
Figure 1
Figure2
gl
8/20/2019 Fun Electronics Projects for the Experimenter (1)
59/189
m?nmffimsu||nomcr
Parts
List
-
6 VoltsFrom
12V
Batteries
lC1
-
7806
ntegrated
ircuit
C1
-
1,000
uF,16WVDC
electrolytic
apacitor
C2
-
100
uF,12
WVDC
electrolytic
apacitor
Fl
-
2A fuse
ldeas
o Explore
To earnmore bouthedevice r ogetbetter erformance:
o
Replace
he ntegrated
ircuit
lOl)
with
a
7805
or 7809 o
get
out-
put
voltages
f 5V and
9V.
o
Explain
heditference
etweenhis inear
oltage
egulator
nda
switch-modeegulator
sed n
computer
ower
upplies.
o
This
ircuit an
alsobe
used
n nonregulated
ower
upplieso
get
a regulatedVx 1Aoutput.
o
lt's
possible
o
get
a nega
Recommended