Páginas DesdeRadio Electronics January 1991
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Transcript of Páginas DesdeRadio Electronics January 1991
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8/18/2019 Páginas DesdeRadio Electronics January 1991
1/4
UILD A
NEGA
TIVE ION GENER TOR
I F
Y O U V E S EE N D VE RT IS E
-
me n ts fo r n eg
a tiv
e ion
gene
ra
to
rs
in mail- o rde r
ca
ta
l
og s
and wondered how
t
hey work.
t
hi s
project is for
you. The simple vers ion de
sc
ri
bed h
er
e p ro
vi d
es in
si gh t
in to th e ir theory and
app licatio
ns ,
an d is bo
th
in
formative and en te rt a in ing .
Som e of
th
e d
e m o n
s t r a
tions you ca n do w i th
.i
t will
a m a z e y o u a n d your
friends .
Many cla im s
ha v
e been
mad e for th e benefioial at
t r i b u tes
o f
n eg a t ive at
mospher ic io
ns
on human
and
plan
t life , es
pecia
llyby a
Dr. Albe rt Kru eger of the
Un ivers ity of Ca lifo r
nia
.
Stu d ies h ave s hown that
negative
io n
s promote
ph
ys
ical
a n d
men ta l alertness
a n d w
e ll-b
e i n g ,
w h i l e
positive at mosp h er ic ions
(su
ch
as in
pollu
ted a ir )
ca u se d
isc
om f o
r t
a n d
la
ssi
tu de.
Certa in negative
io n
prop
erti es can be demons trated.
F
or
example, the su r round-
ing air after a thunde rsto rm
smells cle
an
an d fre
sh
.
du
e
to gen erat io n of n egative
i
ons
fr
om
lig h t n i ng. The
negative ions t tac h to
sm oke . du
st.
a n d p
ol l
en
p
articl
es,
brin
ging the m to
t
he
g r ound to di s
ch
a rge ,
leavt n g fr esh , c le an a ir.
Tha t s w hy a cool ro
om
with
a b reeze is invi gora ting .
comp a re d wi
th on
e that s
st i
flingly h eated . Cool a ir is
gen e ra lly n eg atively i
oni
zed ,
wh
erea
s h ea ted a ir is ge ne
ra
lly
po s
itively i
on i
z
ed
.
Negative ions a re a ir
mo l
ecu les
with
on
e or more excess elec
trons ,
produ
ced in th is
case
by a
low-power. 9 to 14-
ki l
ovol t DC
supp ly
Th
e po
si
tive terminal is
gr o
u n
ded, a nd the othe r th e
em
itte
r ) is a n eedle ex
pose
d to a ir.
To generate positive ion s . the po
l
ariti
es w
ould
be reversed.) Extra
electro
ns on
t
he
em i
tt e
r s surface
produce a hi
gh
local elec tric fi
el d
owing to its pointed s
ha
pe . Th e
electrons ex it th e em itter needle s
uild this negative
ion generator and
u
some
charge
in your life
ANTHONY J CARISTI
WARNING Thisarticle deals with and
involves subject matter and the use of
materials and substances that may be
hazardous to health and life. Do not at-
temptto implement or use the information
contained herein, unless you are experi-
enced and skilled with respect to such
sub
ject matter,
materi a
ls , and sub -
stances. Neither the publisher northe au-
thor make any representation as for the
completeness or the accuracyof the infor-
mation contained herein, and disclaim
any liability for damages or injuries,
whether caused byor arisingfromthe lack
of completeness, inaccuracies of the in-
formation, misintepretations of the direc-
tions,misapplication of the information, or
otherwise.
surface due to th e polariza
tion of surrounding ai r mol
ecu les b
etween
the emitter
n e
edle
a n d
g r oun
d.
T h
e
elect rons collide
w it h t he
air
mol
e
cul
es a n d p r o d u ce
negat ive io ns .
A co mmo n misc onc ep
tion reg
ardin
g
high
-voltage
corona
or
arcing is that elec
trons
ar
e overcrowded on
the tip , and
forced
off by
mutual
r
epulsion
. What ac
tually
causes corona is
th e
high electric field
at
th e tip.
w hich is direct ly propor
tional to
th
e voltage. and is
enhan ced by
sharpenin
g
an
electrode
ti p
to a fine
point
.
T h
e
h i
gh electric field
s trains th e air
mo lecules.
polarizin
g them by a
phe
nomenon call
ed
dipole po
larization. If
th e
electrode is
positive. electr on s are lite r
a lly ripped of f,
c re a ting
positive
ions. or if th e elec
t ro d e is ne gative . they re
forced
to accept electrons.
creating ne
gative ions
.
High-voltage supplies like
those in TV s
need
careful
design , so
no
undesired dis
c o n t i n u i t i e s l i k e
s r
p
p oin ts o r edge s cause
arc
in g. However. for th e nega
tive
io n
generat or d iscussed
here. th e goal is to generate
corona,
no
t to
avoid
it. and
th e high electric field in the
vic in i ty of a discontinuity
more readily polarizes
and
i
onizes
air
molecules
.
The reason
fo r
th e hi gh
electr ic field at the
ti p
of
needle is du e to it s sma lllocalized
radius of curvature. A sphere has
a
mu
ch
more
uniform
e
lectric
field
at
its
surface, due
to
it s
co n
s tant and
mu ch larger
radius.
The audible
hiss
caused by a
high-voltage di scharge is ca lled
co rona
wind.
and is often
heard
in older la rge-screen color TVs .
es pecially on humid
days
. wh
en
t
he br
eakdown potential of th e
»
su
rr o
und in g a i r is
reduced. mak
- z
ing th e flyback t rans former a rc. j;
You can often
also
feel it . if
th e
corona is strong enough .
Th e
negative
io n generator de-
4
-
8/18/2019 Páginas DesdeRadio Electronics January 1991
2/4
C2
1 ~ I F
04
1H4148
03
1N4148
R2
2200
.-
_
+
lM317T
TIP 8
~ ~
OJO
UT
IN
B C E
normall
y
quit
e small, while th e
flyb ack
tr
a n s f o r m e r ou tp u t
windin
g
norm all
y
h as ab o u t
2000-2500
turns . inducing - 3
to - 4 kilovolts .
Sinc
e
th
e ne
gative io n
gener
ator
nee ds to
produc
e - 9 to
- 1 4
kilovolts DC, a ladder voltage-trt
pIer
with
six diode-capacitor
rungs is u
se d
to half-wave
rectif
y
and
multiply
th e
flyback t
ra
ns
form
er output
voltage. I ts oper a
t ion
is b e s t u n d e r s t o o d in
R4
5600
02
1
8
1.. 1
+ - - -,1
4 L ~ L N E S2 : \
D CELLS)
07
SK3067/502
C5
.001
lEOl
BATTERY. :
01
OPERATED :
ft
9VAC-
- - - - ......- 02 Cl
1H4004 1000flF
C4 C3
-+---....-.-
.001 .001
H ~ h
09
SK3067/502
010
SK3067/502
.001
E
MITTER
NEE
DLE
ISEETExn
USE
EARTH GROUND
IFBATTERY OPERATED
fu n d a
m e n t a
l
fr e q u
e n cy w as
23. 26 kl-lz, altho
ug
h hi
gh
er har
monics gr e
atly
exte
nd th e to tal
b
andwid th
. Al
so ,
t
he
p
eak
-to
pe
ak b if tla r prim a ry winding
voltage is fou r ti
me s that
of
th e
supply.
Th e
as table sq
ua
re wav e in
duc es voltage
into
t
he
flyback
t r a n s f o rme r
o u t p u t
Wind ing ,
proportional
to
th e
t ransformer
t u r n s
ratio . A flvb a
ck tr an s
form
er
bifilar
primary winding
is
FIG. 1 THE SCHEMATIC OF THE NEGATIVE ion generator. T2 is a TV flyback trans
former; only its output winding is used, and new feedback and bifilar primary windings
are woundon the ferrite core. The bifilarprimary winding goes to the collectorsof astab le
1 2. Its square wave induces high voltage into the flyback transformer output winding,
boosted followed by a ladder voltage-tripler - 9 to - 14 kilovolts.
v
TO FLYBACK TRANSFORMER
FERRITE
CORE
FIG.
2
THEPARTS-PLACEMENTDIAGRAM
for
the main PCboard ; 01, 02, and ICl have
U-shaped 1x l inch copper heatsinks, with silicone grease for heat transfer; each goes
on the main PC board without insulators. In the prototype, Sl , S2, Fl, and NEl were
omitted, and T2was salvaged from a small-screen TV; note the new feedback and bifilar
primary windings. Pin 7
had the highest resistance relative to the flyback transformer
output lead, so it becomes ground.
The
circuit
Th e
sc
he
ma t ic of
th e
neg
at
ive
io n generator
appears
in Fig. 1:
T2 is a TV flyback transf
ormer
with
an open
ferrite core partially
enclosed in an
aluminum brack
et.
Th
e only
original
connections
used are on e low-voltage tap as
I ground. and th e lead
connecting
to th e flyback
transformer
out
put winding
at r ight).
T he o t h e r low-voltage tap s
a re n t u se d.
and
the ne w
feed
back and bifilar p ri ma ry w in d
in gs are
wound on
the ferrite
core.
Th e bifilar primarywindin
g
goes
to
th e
collectors of
an
asta
ble multivibrator
made up
of Ql
an d
Q2. w it h t he center ta p
dr i
v
en by
the
+3 - 5
vo lt s DC
from
ICI.
Th e a sta bl e e ne r
gy-
stor
age
e l em e nt s a re t h e i n du c ta n ces of
th e n ew feedback
an d
bifilar pri
mary windin
gs.
Th
e term bifilar means a
pair
of
transformer
windings
optimally
coupled by having been wound in
th e
same direction. either
adja
c
ent
to
or
. preferably.
superpo
sed
on top
of
on e
another
.
Th e
f
ee d
back winding goes
to
th e bas
es of
Ql and
Q2 for positive feedback.
w it h t he c en te r t ap driven
by the
+
3 -5 volts
DC
from
ICI
through
R3.
Th e
transistors ar e
then
for
ward-biased by
th e opposite en d
s
of
each
halfof
th e
feedback wind
ing.
When power is applied. the cur
rent
through
Ql and Q2 is une
qual, d u
e
to
diff
erence
s
in
dopin
g . la
yer th ick n
ess .
an d
base-em itter B-El turn-on volt
age. That s
what
c
ause s
oscilla
tion
; if all
th
e
astable
p
art
s w
er
e
perfectly balanced nearly
impo
s
s ible , it mi ght
not
oscillate at all.
Wh i ch
ev er
t r a n si st o r ca
r r
ie s
hi
gher
current
saturates
du
e to
positive base feedback. and the
other
cuts
off.
Wh
en
t
he sh arp in cr
ease
in
transistor current i n h al f
the bi
fil ar p r i m a ry winding is max
imiz ed . t h e induced vo ltage
revers es
.
so
the
second
tran
sisto r co n du cts and th e
first
on
e
cuts off.
Th e
collector waveform
scribed h ere is low-cost.
ea s
y to
build. and u s
es
a high-voltage
flyback transformer from an old
black-
and-whit
e
TV.
It ge
nera
tes
hi
gh
voltage . but at very low cu r
r
ent.
However.
th e
safety precau
tion
s
ta ke
n for a
ny high -
voltage
device s hould
be
observed h
er
e.
-
8/18/2019 Páginas DesdeRadio Electronics January 1991
3/4
l
SILICO NE
RUBBER
AC output
waveform
from
th e
flyback
transformer
is coupled to
th e anode of 07 via C3
and
C4,
where 07 charges C4 . The
action
is repeated again via 09 , which
chargesC5 .The DC
potent
ials
on
C3-C5
add tripling the voltage
from th
,e flyback transformer
Winding. The anode of
010
is the
output
of
the
negative ion gener
ator,
and
should
be
at
- 9 to - 14
kilovolts DC.
Power is supplied by either a
standard full-wave rectifier fol
lowed
by variab le voltage
reg
ulator
ICI , or four
series 0
cells
producing 6 volts DC. Although
SI S2 FI
and
NEI
are
s
hown
in
Fig . 1, t
hey
were om i
tted
in the
prototype . ICI co
ntro
ls th e DC
voltage fed to th e oscillator via
Rl . Since t
he
negat ive ion gener
ator outpu t must be - 9 to 4
kilovolts ,
and
the exact flyback
transforme
r
turns
ratio
is
nor
mally
unknown
adj usting RI is
mandatory.
Once
RI is
set
the
negat ive ion
gene
rator output
voltage will be
stab
le.
o r
;:[
NPUT
FROM
I I
FLYBACK
I I
TRANSFORMER : 07 I
(MAIN
BOD
Y : f 08
WINDING : r
J
CARR IESHVDC) I :
1
~
i *
I r
I I I
I I I
C6 C7i,
:
HVDC
OUTPUT
0
..l
FINAl
HVDC
TR1PLER
OUTPUT
RUBBER
TE
STL
EAD
FL
YBACK
OUTPUT
RUBBER
TEST
LEAD
-I
RES IN t -------.
EMIITER
l _
NEEDLE
e,
:>
2
C
FIG. 4- THE NEGATIVEIONGENERATOR,showing the case, T2, plastic soda bottle, and
the top of the high-voltage PC board , wit h 05, 07, 09, and C3-C8. Both the plastic soda -<
bottle and high voltage PC board are held in place with RTV The neck is sealed with
I
casting resin to wit hin
Yo
- inch of the top; cover the needle with a cork when unused.
FIG. 3 THE PARTS-PLACEMENT di
agram for the high-voltage PC board. The
parts shown include high-voltageceramic
disc capacitors C3--C8, and selenium rec
tifiers 05--010. 05, 07, and 09 go on the
component side (solid lines), whi le 06,
08, and 010 go on the foil sid e (dashed
lines) .
segments . The AC
waveform
from the
transformer is coupled
to
05
and
06
via C3 charged
through
05
act ing as
a clamp.
The
peak-to -peak
magnitude
of t
he
AC
waveform
at
th e
anode
of 05 equals that of the fl
yback
transfo rmer
outp
u t Winding
wit
h a negative DC
component
of
half t
he
peak
-to
-peak value.
The
NOTE:The fo llowing are available from
Anthony J. Car
isti
, 69 White Pond
Road , Wald wick, NJ 07463: Two
etched and dr illed PC boards (one
each for the main and voltage-tripler
sections) for $15.95, IC1for $3.25, 01
and 02 fo r $2.75 each. Please add
$2.00 for postage and handling with
each order; NJ resid ents please add
7% sales tax.
Semic
onduc
to rs 01, 02 1N4004 sil
icon diode
03, 04 1N4148 silicon diode
D5 01o RCA SK3067/502 high-voltage
diode. 12 kilovolts PIV
LE01
l
ight-emitting diode for the bat
tery-operated version
01. Q2 TIP31B NPN transistor
IC1 LM317T adjustable voltage
regulator
Other components
F1 Q.5-amp slow-blow fuse with holder
NE1 120 volt AC neon-bulb assembly
with 47-100K built-in series resistor for
the p lug- in version (Radio Shack
272-712)
NE2 neon bulb, type NE2 (not the part
number). optional for experiment (see
text)
S1 SP sT toggle switch
S2-S PST toggle switch
T1 18 -volt center-tapped transformer
(RadioShack 273-1515 )
T2 standard TV f lyback transfo rmer
(see text)
Capacitors
C1 1000
tJ.F, 25 volts, electrolytic
C2 100 tJ.F 16volts. electrolytic
C3 C8 0 .001
tJ.F, 10 kilovolts, ceramic
disc
C9 0
.001 tJ.F, 500 volts, ceramic disc,
optional for aluminum can/neon bulb
experiment (see text)
M is cel laneous :
Plastic
case
(7.5 x 4.25 x 2.25-inches, RadioShack
270-224), enamel magnet wire, three
wire line cord, emitter needle (made
from either straight pin or sewing nee
dle), RTV silicon rubber, heat sinks, four
alkaline 0 cells (optional for battery
operation), 2-liter plastic soda bottle,
and a sewing needle.
PARTS LIST
All resistors are Yo-watt , 5%, un less
otherwise noted.
R1 1000 ohms, PC-board mounted po
tentiometer
R2 220
ohms
R3, R4 560 ohms (the former for the
astable-flyback transformer combina
tion, the latter optional for the battery
operated version)
R5 R6 200 - and 40-megohm series
h igh vol
tage
f ocus d iv
ide
r, RCA
SK3868/DIV 1 , used for an optional
high-voltage range extender for a con
ven tional h igh impedance (10
megohm) voltmeter (see text)
R7 2 7 megohms
-
8/18/2019 Páginas DesdeRadio Electronics January 1991
4/4
FIG. 5-THE BOTTOM OF THE HIGH-VOLTAGE PC board, showing 06 , 08 , and 010, and
the attachment points of the
ground
lead and both high-voltage leads.
Construction
Next,
we
ll di s cu s s
co
n
struction , foc
using
on the ma in
and vo ltage-trip le r PC
boa
rds ,
th e plastic cove r for t
he
voltage
tr
ip ler PC board made from the
top third of a 2-liter plast ic soda
bottle, the em itter n eedle , an d
t
he
cu to
ut
in
th
e
lid
of
th
e plastic
case for the flyb ack transfo
rm
er.
Fig
ure 2
shows
th
e p
art
s-place
m
en
t diagr
am
for t
he
m
ain
PC
board , and Fig . 3 the ladde r volt
age-tripler
sectio
n . R
em
emb
er
to
add S I , S2, FI , an d NEI off the
m
ain
PC bo
ard,
as s hown in Fig.
1, if you want th
em
.
Th
e main
sec
tion
includ
es
th
e
re
gulated
supp ly, oscillator, and
flyb
ack tran
sform
er
, an d goes
on
th e s ing le-s ide d PC bo
ard
men
tion ed in the parts lis t , wit h the
fo il p attern s h own h ere.
Th
e
h igh-voltage PC board conta ins
t
he
l
adder
vo
ltage
trtpl
er
, con
nec ted to the ma in PC board by
two le
ad
s , an d t
he
em
itte
r n eedle
is ab ove th e hi
gh-
vo
lt
age PC
bo
ard.
In Fig. 2 , QI , Q2 , an d ICI
n eed
heat
sinks ; you can buy
th
em, or
m
ak
e th em
from
1x l
in ch
copper bent
in
a U, with
s ilicone g
rease
for h eat trans fer.
The h ea t s in ks go on top of t
he
PC bo ard
wit
ho
ut
i
ns
ula to rs .
Neon lamp
asse
mbly NEI
acts
as
a n in i c a t or ,
n
h a s a
47
K- 100Kresis
to r
in se ries with
it . For ba tt
er
y op
era
ti
on
, u s e
L
EOI
in
se
ries
with
R4; u se al
kaline ba
tt
eries,
not
ca rbon-zi
nc
.
Us e a 3-wire cord with ground , or
an ea r th ground in
batt
ery-oper
a ted versions. The voltage-tripler
se ct ion is
built
to avoid a rc i
ng
and
sho
ck. Cut t
he
top th ird off a
2-li ter pl a sti c
soda
bo
tt l
e ,
as
shown
in
th e le
ad ph
oto ,or u se 4
in ch d iam e t
er
pl a s
ti
c PVC
plumbin
g pipe.
Use 18- gauge rubb er-co
at
ed
test
l
ead
s to con
nec
t t
he hi
gh
vo ltage PC bo
ard
to b o th the
flyba
ck tran
s f
ormer outpu
t
and
th
e n e
edl
e, to
withstand
h i
gh
vol
tage,
but n
ot until indi
ca ted
(more below).
Th
e h eavy voltage
t ripler ou tp u t lead is so ldered to
the e
mitte
r n eedle , which goes
upward through the plastic soda
b o
tt l
e an d
pr
oj ec ts o
ut
of t
he
n eck, which is filled wit h casting
re
sin
. Don t fill t
he
ne
ck
wit h res
in all t
he
way to th e top; leave
inch of the n eck open, so you can
cap
th
e needle with a wine bottle
cork
when
not
in
use.
08
06
FIN L
HVDC f oiE
OUTPUT
Th
e v
ol t
age t ripler s
how
n in
Fig. 3 co
ns
is
ts
of ceramic di s c ca
pacit
or
s C3
-C8
, a n d
hi
gh -
volt
age selen ium rectifiers
05-010
.
Note that 05 , 0 7, and 0 9 go on
t
he
compo
nent
s ide of t
he
PC
boa rd , whil
e
D
fi.
0 8, and
010
go
on the foil
sid
e. They re common
to
most
TV s , so
most
TV repair
s
hops should
s tock them; see
th
e
parts list.
Fi
gur
e 4 sh
ows
a
phot
o of t
he
negat ive ion ge
ne
ra tor, wi
th
the
closed case , flyba ck transforme r,
plas t icso
da
bottle, an d top of t
he
hi
gh-voltage PC board show i
ng
05
,
07
, 0 9 , a n d
C3 -C8
.
Th
e
hi
gh-
voltage PC bo
ard
is h eld in
place ins id e t
he plasti
c so
da
bot
tle top using RTVs ilico
ne rubb
er,
and th e
pl a
sti
c so
da bottl
e goes
on th e top of
th
e case
th
e same
way, for a water-tight se al that
avo i
ds
con
de
nsa
ti
o
n,
a
nd
h as
good high -voltag e att r ibutes .
Th
e markings and s izes of the
hi
gh -voltage TV diodes used in
t
he
vo
ltage tripl er di
ff
er
from
t hose on s t n da r d
di
od es.
Th
ey r e
much
l
ar
g
er
, and h ave a
very
high
peak-inverse vol tage
(PIV) ra ti
ng
. Also, on a conven
ti
on
al
diod
e,
th
e cat h ode is n or
m all y m
ark
ed with a b and ,
wh
eth
er a wh i te b
and
on a black
body for such low-voltage rec
ti fi
er
s
as
t
he
IN4
00I
, or a r
ed
band on a clear glass body, as
wi
th
t
he
IN4148
or
IN914 .
In high-voltage TV
diod
es, the
body
is ge
nera
lly either wh
ite,
bla ck , or see-t
hroug
h. In Fig . 4,
05
and 07 are whi te wi th a b
and
of bla
ck
s ig
ns on th
e r i
ght
end , while 0 9 is bl ack with a
FL
YB
CK
OUTPUT
UNDERSIDE O
VOLT GE TRIPLER
P BO RD
GND
WIR
dashed
band
of wh ite - s ig
ns
on the righ t en d. The en
ds
wit h
t
he
b
and
s
ar
e t
he ca
t
ho
des
, f
or
both diode body types ; t
he
reason
for t
he
s igns on 0 3
and
05 is
th
at circu
it
power is
norm
ally
co
ns
ide re d as b eing
ex t
racted
from
th
e c
athod
e en
ds
in
TV,
and
is ca lled B . In Fig. 5 , 06 , 0 8 ,
and
010
all h ave bands of
s ig
ns
on th e ca thodes .
A 3 x 3-inch hole was made in
th
e case top for t
he
flyback trans
f
ormer
; adjust you
rs
as needed.
Dori t con
nec
t the voltage-tripler
PC board to the mai n PC board
un
til t
he fin
al c
hec
ko
ut
below;
pu
t it
as
ide and let t
he
RTV dry
overn i
gh
t .
Th
e so
da bottl
e and
the hi gh-voltage PC
board
a re
h eld in place u
sin
g RTv.
Th
e
rub
ber-co
at
ed test leads con nect the
fl
yb
a c
k-tran sformer ou
tpu t to
the voltage tripler and the voltage
tr ip le r to the em itter n eedle; t
he
th in wire is t
he Q
round.
A flyback transforme r is also
ca lled a tu ned
tran
s fo
rm
er, and
co
ns
ists of a ferrite co re s u r
ro
und
ed by a metal
br
a
ck
et, with
a l
ar
ge coil of windings coated in
pl a s ti c o r cer
ami
c
with
a n
x
m y
hi
gh
di ele
ctric
br
e
ak
down vol
tage
. Oft
en
,
as
wi
th
t
he
flyback
tr a
nsfor
mer
used in the
pro to type , t
he
re are add
it
ional
low-voltage o
utp
ut windi
ng
ta
ps
(seve n , in that ca s e ) p
laced
a round a plastic
ri n
g on o
ne
s ide
of the tr a
ns
f
ormer
coil, that have
equally h igh-voltage
br
eakdown
characteristics .
That s all we have room for.
Next m
onth
we ll fini
sh up
th is
project. R-E