close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2403624

код для вставки
July 9, 1946.
I. WOLFF
2,403,624
APPARATUS FOR AND METHOD ‘OF PULSE KEYING
Filed Dec‘. 50, 1937
wgrl pa
sin.““.0Lox ,
{noun
~ Patented I July
1946
r 2,403,624
'_ {UNITED/STATES PATENT oFFICE
1
2,403,624-
/
'
.
APPARATUS FOR AND METHOD OF PULSE
-
_
KEYING
Irving Wolff, Merchantville,
J., assignor to
Radio Corporation of America, a corporation of
Delaware
- Application December 30, 1937, Serial N0.V182,418
’ 11 Claims.
1
(c1.250—17)
'
.2
.
' My invention- relates to an apparatus for and a ‘
method of pulse keyingand more speci?cally to a ‘
keying system in which the marking pulses are .
of extremely short duration.
~ _ ‘I am aware that numerous high speed mechani
cal keying systems have been devised for form
ing telegraphic characters. It has also been pro
posed to use multivibrators for generating a key
ing pulse, The multivibrator is used to establish
currents of saw-tooth wave form. These currents
are applied to a limiter which selects the peaks
and thereby establishes a short marking impulse.
>
-
-
>
'
ampli?er l is. biasedLne'gatively with respect to
cathode I6 byaibiasing battery l1.’
.
The anode. of the ampli?er‘ ‘I is connected
through a low impedance inductor I9 to the pos
itive terminal of a B battery 2|. The negative
terminal of ‘the battery 2| is‘connected to the
positive terminal of the biasing battery I'I, cath
ode I6, and ground. The inductor I9 is coupled
through‘ a blocking capacitor 23 to the grid 24
of a second ampli?er 25. ,The grid Ziisbiased
negatively with respect to. cathode 26 by a grid
resistor 21 vwhich is connected to the'fnegative
terminal of the biasing battery 25. The natural
period of the inductor 25 and associatedcapac
quired, the multivibrator type keying may su?ice.
When‘ larger powers and extremely short mark 15 ities is preferably of the order of the natural pe
riod of the applied pulses 29.
'
'
ing pulses are required, the problem is not as
The anode of ampli?er 25 is connected through
easily solved. For example, in systems which re
a low. impedance inductor 3| to the positive termi
quire marking pulses of the order of a micro
second or..less duration and substantial amounts - nal of the B battery 2!. A potentiometer 33 is
of power,‘ it becomes increasingly di?icult to 20 shunted. across the inductor 3|. The inductor is
coupled through a network 35 and a serially con
shorten thepulses and equally dif?cult to effi
nected source 31 of biasing voltage to key an oscil
ciently amplify the pulses.
1
lator 39 or the like. ‘The output of the oscillator
I propose to apply the initial pulses-to a device
In systems in which small keying powers are re
which not'only ei?ciently ampli?es the pulses
but also shortens the duration of the’ pulse. The 25
device in certain respects resembles a resistance
coupled ampli?er in which inductors are sub
stituted for the resistances, and in which only
the positive pulses are transmitted. Keying or
is applied to an antenna 4| or otherload circuit.
‘Having described the circuit, the mode of oper
ation will be set forth; In the condenser charg
ing circuit of the multivibrator, pulses of current
are available. These discrete pulses l5 are applied
to the primary 90f the transformer 5. The pulses
marking devices of this type are used to ‘start and 30 l5 are suitably phased by the transformer‘ II so
that the grid I4 is driven positive with respect to
stop oscillators,v ampli?ers, or modulators.
In
practice, myinvention may be applied to obstacle
detectors operating on the radio echo principle,
radio operated altimeters, television synchroniz
ing impulses and the like.
I
'
One of the objects of my invention is to provide
means for generating keying pulses of very short
duration and substantial amplitude.
its cathode I6.
p
1
"
‘
_
r The ampli?ed positive pulses act on the in—
ductor I9 and, due to, its differentiating effect
in a mathematical-sense, create negative pulses
during the rise and positive pulses during the fall
of current of pulses I8. Due to the action of
the resonant circuit, including inductor l9 and
.
itsassociated capacities in tubes 1 and 25, and
Another object is to provide means for eniciently 40 the ‘shunt resistor 21 and grid circuit losses in
amplifying pulse currents having a, duration of
tube 25; a highly damped wave train- 29 is
the order of microseconds.
created. It will be observed that the duration
An additional object is to provide means for
of the ?rst negative and ?rst positive portions
amplifying pulse currents of short duration and
oi the wave train 29 is substantially equal to
simultaneously decreasing the pulse duration.
the duration of the applied-positive pulse, Thus
A still further object is to provide means for
the original pulse duration is decreased.
keying an obstacle detector transmitter by mark- '
The wave train 29 is applied through the
ing pulses of extremely high periodicity.
‘ blocking capacitor 23 to the input of the second
‘My invention may be best understood by refer
ampli?er 25. This ampli?er is biased so that
ence to the accompanying drawing which is a‘ 50 its output current is near cut-01f. Because of
this bias, the ?rst positive pulse of the wave
schematic diagram. A multivibrator I,' which
train '29, and sometimes the following positive
generates currents of saw-tooth wave form 3, is
connected through a‘ transformer 5 to a vacuum ‘ pulse, will actuate the ampli?er 25. The in
tube ampli?er l. The‘primary 9 of the trans
ductor 3| will have established therein vampli?ed
former 5 may be shielded from thesecondary ll. 55 wave trains 30 which are highly damped due to
byan electrostatic screen I3. The secondary. II
theresistance 'of the potentiometer‘ 33, and the
energy absorbing characteristics of the oscil
is preferablyof low impedance and, together'with
lator input. The duration of the positive pulses
the'input capacity of the ampli?er ‘I, may be ar
of the wave trains 30 will again be shortened.
ranged to resonate at substantially the period of
the applied pulse I5. The grid electrode I4 of the 60 These positive pulses 32 of the wave trains 30
2,403,624
'
'
33
will overcome the bias 3'! which normally pre
vents the oscillator 39 from functioning and
will abruptly key the oscillator. The oscillator
6. The method of establishing keying pulses of
extremely short duration which comprises gen
erating discrete discharge currents, converting
89, thus keyed, will generate oscillatory currents
34 during a portion of the ?rst positive pulse
said discrete discharge currents into discrete
pulses, transforming said discrete pulses into
v highly damped oscillatory currents, amplifying
duration. The pulse duration may be adjusted
from a fraction of a microsecond to several mi
he first positively phased oscillation, converting
croseconds. The keying pulses may follow each '
said ampli?ed oscillation into a second series of
other at the required rate of keying.
highly damped oscillatory currents, and deriving
4
It should be understood that the transformer 10 from said last oscillatory currents a positively
5 may be replaced by an inductor, blocking ca
phased pulse of extremely short duration.
pacitor and grid resistor. In order to effectively
'7. A pulse keying device including a source of
match impedances, the inductors may be used as
discrete pulses of current of a single phase,
autotransformers.
means for converting each of said pulses of sin
I claim as my invention:
'
15 gle phase into currentsrof positive and negative
1. A pulse generator device including in com
phases forming highly damped wave trains,
bination a source of rapidly varying currents,
means for selectively amplifying currents of the
means for transforming said currents into highly
?rst positive phase of eacli of said wave trains,
damped wave trains, means for amplifying the
and means for creating from said positive phase
positive pulses of said wave trains, and means 20 currents a second current having negative and
for applying the ampli?ed positive pulses to an
positive phases of less duration than said ?rst
output circuit.
mentioned currents of positive and negative
2. A pulse keying device for a transmitter in
phases.
,
cluding in combination a source of pulses, means
8. A pulse keying device including a source of
for transforming said pulses into highly damped 25 discrete pulses of current of a single phase,
wave trains, means for amplifying the ?rst posi
means for converting each of said pulses of sin
tive pulse of said wave train, means actuated by
gle phase into highly damped waves including
said ampli?ed positive pulse for creating a sec
currents of positive and negative phases, means
ond highly damped wave train, and means for
for selectively amplifying currents of the ?rst
applying the ?rst positive pulse of said second 30 positive phase of each of said waves, and means
highly damped wave train to key said trans
for creating from said positive phase currents a
mitter.
“
second current having negative and positive
3. A keying device including in combination
phases of greater amplitude and less duration
a circuit to be keyed, a source of discrete pulses,
than said ?rst mentioned currents of positive and
means for converting said discrete pulses into a
negative phases.
a ?rst series of highly damped wave trains, means
9. A pulse keying device including a source of
for amplifying the ?rst positive pulse of said
discrete pulses of current of substantially uni
wave trains, means for deriving from said ampli
form duration, means for converting said dis
?ed positive pulses a second series of highly
crete pulses of currents into highly damped
damped Wave trains, means for amplifying the
waves including positively and negatively phased
?rstpositive pulse of each of said second series
currents, the period of said two phases being 01'
of highly damped wave trains, means for de
substantially the same duration as said discrete
riving from said last-mentioned ampli?ed posi
pulses, and means for selecting in each of said
tive pulses a third series of highly damped Wave
Waves the ?rst positive phase currents and ex
45
trains, and means for applying the ?rst positive
cluding
said negatively phased currents where
pulse of said third series of highly damped wave
by the duration of said selected phases is less
trains to said circuit to be keyed.
l
than the duration of said discrete pulses.
4. A keying device including .in combination a
10. A pulse keying device including a source
keying circuit, a source of current pulses, means
of discrete pulses of current of substantially uni
for transforming said pulses into series of wave 50
form duration, means. for converting said dis
trains, means for highly damping said Wave
crete pulses of currents into highly damped
trains, said trains including negative phased
Wave trains including positively and negatively
pulses and positive phased pulses, means for am
phased currents, the period of said two phases
plifying the ?rst of each of said positive pulses,
being of substantially the same duration as said
means responsive to said positive pulses for cre~ 55 discrete pulses, means for selecting the ?rst of
ating a second series of wave trains, means-for
the positively phased currents of each of said
highly damping said second series of Wave trains,
Wave trains and excluding said negatively
said second series of wave trains including nega
phased currents whereby the duration of said
tively phased pulses and positive phased pulses
selected phases is less than the duration of said
and means for applying the ?rst of each of said 60 discrete pulses, means for amplifying said posi
last-mentioned positively phased pulses to a key
tively phased currents, and means for establish~
ing circuit.
ing currents of positive and negative phases of
5. The method of establishing and applying
a durationgcontrolled at least in part by said
keying pulses to a load circuit which comprises,
?rst mentioned positively phased currents.
65
generating discrete discharge currents, convert
11. A pulse ampli?er including a source of pos
ing said discrete discharge currents into discrete
itive pulse voltages, means for converting said
pulses, transforming said discrete pulses into
wave trains including highly damped negatively
and positively phased pulses, amplifying said
positively phased pulses, and applying the ?rst
of said ampli?ed positive pulses to said load cir
cuit.
positive pulse voltages into a highly damped wave
train having negative and positive voltage peaks,
4 and means for amplfying the ?rst positive peak
without amplifying negative peaks of said wave
train.
IRVING WOLFF.
Документ
Категория
Без категории
Просмотров
0
Размер файла
386 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа