close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2108154

код для вставки
‘Feb. 15, 1938.
I
> '
“c. J. VAN LOON
'
‘2,108,154
RECEIVER TUNING CIRCUITS
Filed July 30, 1936
l7
\
,
jams/e KNOB
FREQUENCY
‘c ‘e Ld
3
.
9
r0 1. F.
AMPUF/ERH
4
22
’ ‘/2
WT
‘DC~
,4?‘
.
v
_
'
~
~
INVENTOR
CAREL JAN VAN LOON
BY
I
v
‘
,
"
,
‘
MM/
ATTORNEY
‘
2,108,154
Patented Feb. 15, 1938
UNITED STATES PATENT 'QFFICE
2,108,154
RECEIVER TUNING CKRCUITS
Carel Jan van Loon, Eindhoven, Netherlands, as
signor to N. V. Philips’ Gloeilampenfabrieken,
Eindhoven, Netherlands, a corporation cf the
Netherlands
Application July 30, 1936, Serial No. 93,354
In Germany October 26, 1935
11 Claims.
This invention relates to a circuit arrangement
for assisting the tuning of wireless receiving sets.
Such arrangements are particularly desirable for
sets having automatic volume control, since in
5 this case it is often very difficult for laymen to
?nd the point of correct tuning. The circuit
arrangement according to the invention serving
for assisting tuning is set into operation upon
accurately tuning to the desired carrier wave.
The tuning may be assisted, for example, in that
an optical device is set into operation upon the
correct tuning being reached, or in that not until
this moment the low frequency ampli?er part of
the set is caused to, become operative. The in-
(01. 250-40)
grid 2 of a pentode 3. The screening grid is
connected to a point of a resistance I8 by which
the voltage supply leads are bridged. The cath
ode is connected to the negative conductor by
way of a resistance which provides negative grid
bias. The output circuit of the valve includes a
circuit 4 which comprises an inductance and a
capacity and which may be tuned to the inter
mediate frequency, although as an alternative an
aperiodic circuit may be used. The voltage ac
tive in the output circuit is supplied via a con
of the recti?ers is preceded by greater selectivity
denser 5 to a recti?er B, l which jointly with two
resistances 25b and I3 constitutes a closed direct
current circuit. The output circuit of the tube
3 is in addition coupled via the condenser 8 to a 15
circuit 9 of low damping tuned to the intermedi
ate frequency carrier wave. The voltages occur~
ring in this circuit are supplied to the recti?er
‘i, H, and bring about a voltage drop across the
resistances i2 and H3 in such manner that the
upper point of the resistance l2 becomes neg
ative relatively to the lower.
The two recti?ers may be separated from each
than the other.
other, but preferably, as shown in Fig. 1, they
' vention is, however, primarily intended for a
device in which upon correct tuning further ro
tation of the tuning member is prevented, for
example, by a brake being brought into oper
ation.
According to the invention, two recti?ers are
coupled to the high—frequency or intermediate
frequency ampli?er in such a manner that one
In addition, the recti?ers are
25 connected in such a manner that the recti?er
voltage of one recti?er in?uences the other in
such a manner that this latter recti?es only in
the immediate vicinity of the resonance frequency
and that the recti?ed current of this recti?er is
used for the control of the device by which tun
ing is assisted.
Preferably, the part of the receiving set that
assists tuning solely serves this purpose and rec
ti?cation of the high-frequency oscillations and
— ampli?cation of the low-frequency oscillations
are effected by other valves separated therefrom.
The circuit arrangement is preferably ar
ranged in such manner that the direct current of
the recti?er which is preceded by the greatest
40 selectivity brings about the control.
In order that the invention may be clearly un
derstood and readily carried into effect a circuit
arrangement of this kind will be described here
inafter, by way of example, with reference to
“ the accompanying drawing.
In the drawing:
Fig. 1 shows a circuit diagram of one form of
the invention,
Fig. 2 graphically shows the operation of the
invention, and
Fig. 3 shows a modi?ed form of the invention.
In the circuit arrangement shown in Figure l
the voltage of an intermediate frequency ampli
?er stage (not shown) of the receiving set is
supplied through a condenser I to the control
are housed in a single bulb and have one com
mon cathode. As shown in Fig. 1, the resist?
ance I3 is included in both recti?er circuits. The
resistance it constitutes the input circuit of a
recti?er valve M, the output circuit of which
includes a magnetic braking device I5 which, as
will be described hereinafter, prevents any fur
ther movement of the tuning knob ll upon the
correct tuning of the latter to a carrier wave.
For this purpose, the shaft of the knob has
mounted on it a braking disc it of soft iron. In 35
stead of using a magnetic braking device, it is
also possible to use an electrostatical one.
The device operates as follows:
When the grid of the tube 3 has not supplied
to it signal voltages, neither of the two recti?ers 40
carries current and the grid of the valve M has
such a potential that a current ?ows in the an
ode circuit. The magnetizing effect of this cur
rent is neutralized by a constant current passing
through a second coil H5’, or by a permanent
magnet, so that the tuning knob can be moved
freely. Now, when approaching to the point of
correct tuning, a voltage ?rst occurs through the
circuit 4 so that a recti?ed current flows through
the resistances 24 and I3. The voltage drop
across the resistance !3 is such that the upper
point of this resistance becomes positive rela
tively to the lower one. When approaching still
more to the correct tuning, a voltage will also
occur across the second circuit 9. Due to the 55
2
2,108,154
voltage drop across the’ resistance 13, which is
justment of the tuner element, a control network
also active in the second recti?er circuit, a cur
for said means comprising a pair of recti?ers, a
rent will not flow in the second recti?er circuit
until the alternating voltage active across the
resonant signal input circuit, tuned to a desired
circuit 9 has an amplitude which exceeds the
signal frequency, coupled to one recti?er, a sec
ond signal input circuit, tuned to said desired
value of the voltage across the resistance l3.
This action is illustrated in Figure 2 by means
frequency coupled to the second recti?er, the
selectivity at the second circuit being greater,
of a few curves. The curve (1. represents the volt
age across the resistance l3 as a function of the
means for impressing signals on said signal cir
cuits, means responsive to current flow in said
one recti?er for preventing current flow in the 10
10 frequency of the arriving signal.
The point 6
corresponds to the resonance frequency of the
circuit 4. The curve 1) represents the voltage
across the circuit 9 as a function of the fre
quency. It is obvious that the recti?er ‘I, II is
15 not caused to become operative until this voltage
second recti?er until the signal amplitude at the
second input circuit attains a desired value, and
means responsive to current ?ow in the second
recti?er for controlling the operation of said ?rst
means, said tuner control means comprising a 15
exceeds the voltage across the resistance l3, con
sequently, when in tuning a frequency corre
sponding to one of the points 0 or d is reached.
Not until then has the resistance [2 occurring
magnetic brake device constructed to prevent
adjustment of the tuner element when energized.
3. In combination with the adjustable tuner
through it a potential drop which applies such
adjustment of the tuner element, a control net
a bias to the tube [4 that the brake is set into
operation. It is easy so to proportion the cir
cuit 9 that the device is set into operation at a
Work for said means comprising a pair of recti
frequency which differs very little for example
25 by a few hundred cycles, from the natural fre
quency of the circuit 9.
In the circuit arrangement described it is en
sured that the action of the brake is practically
independent of the intensity of the signal voltage
and the adjustment is but slightly critical.
The
tube M can be connected so that the anode cur
rent increases upon the arrival of a signal. In
this case, the second coil on the magnet core of
the brake can be dispensed with. The control
voltage for the braking device may also be de
rived from a further resistance, for example I2,
since it can be obtained by adequate proportion
ing that the current of the recti?er path 6-—1
ceases when the current across the second path
40 attains a given value. Numerals iii and I9 de
note appropriate I. F. bypass condensers.
Figure 3 shows a slightly different circuit ar
rangement which diifers from that shown in
Figure 1 in that the valve 3 also serves as a brak
45 ing valve.
For this purpose the voltage active
across the resistance I2 is led back to the control
grid of this valve, and the braking device 15 is
included in the anode circuit of this valve. Thus
a saving of one tube is obtained.
In this circuit
50 arrangement it is desirable to provide a device
that limits the voltage active in the output circuit
of the valve 3. A glow discharge lamp 20 is
provided for this purpose. The resistance 23
as well as the condenser 2i serve for smoothing
55 the voltage led back. The resistance 22 is the
input resistance for the grid of the valve 3.
What is claimed is:
1. In combination with the adjustable tuner
element of a radio receiver, means to control ad
60 justment of the tuner element, a control network
for said means comprising a pair of recti?ers, a
resonant signal input circuit, tuned to a desired
signal frequency, coupled to one recti?er, a sec
ond signal input circuit, tuned to said desired fre
65 quency coupled to the second recti?er, the selec
tivity at the second circuit being greater, means
for impressing signals on said signal circuits,
means responsive to current ?ow in said one rec
ti?er for preventing current flow in the second
recti?er until the signal amplitude at the second
input circuit attains a desired value, and means
responsive to current flow in the second recti?er
for controlling the operation of said ?rst means.
2. In combination with the adjustable tuner
75 element of a radio receiver, means to control ad
element of a radio receiver, means to control
20
?ers, a resonant signal input circuit, tuned to a
desired signal frequency, coupled to one recti?er,
a second signal input circuit, tuned to said de
sired frequency coupled to the second recti?er,
the selectivity at the second circuit being greater,
means for impressing signals on said signal cir
cuits, means responsive to current ?ow in said
one recti?er for preventing current ?ow in the
second recti?er until the signal amplitude at the
second input circuit attains a desired value,
means responsive to current flow in the second
recti?er for controlling the operation of said
?rst means, said signal impressing means includ
ing an ampli?er, and said ampli?er also being 35
included in said last named responsive means.
4. In combination with the adjustable tuner
element of a radio receiver, means to control ad
ju'stment of the tuner element, a control network
for said means comprising a pair of recti?ers, a
resonant signal input circuit, tuned to a desired
signal frequency, coupled to one recti?er, a sec
ond signal input circuit, tuned to said desired
frequency coupled to the second recti?er, the
selectivity at the second circuit being greater, 45
means for impressing signals on said signal cir
cuits, means responsive to current flow in said
one recti?er for preventing current flow in the
second recti?er until the signal amplitude at the
second input circuit attains a desired value, means
responsive to current flow in the second recti?er
for controlling the operation of said ?rst means,
said tuner control means comprising a magnetic
brake device, and said controlling means includ
ing a tube in Whose space current circuit is con 55
nected said brake device.
5. In combination with the adjustable tuner
element of a radio receiver, means to control
adjustment of the tuner element, a control net
work for said means comprising a pair of recti 60
?ers, a resonant signal input circuit, tuned to a
desired signal frequency, coupled to one recti?er,
a second signal input circuit, tuned to said de
sired frequency coupled to the second recti?er,
the selectivity at the second circuit being greater, 65
means for impressing signals on said signal cir
cuits, means responsive to current ?ow in said
one rectifier for preventing current flow in the
second recti?er until the signal amplitude at the
second input circuit attains a desired value, means
responsive to current flow in the second recti?er
for controlling the operation of said ?rst means,
said signal impressing means and controlling
means both including a common ampli?er tube.
6. In combination with the adjustable tuner
3
2,108,154
element of a radio receiver, means to control
adjustment of the tuner element, a control net
work for said means comprising a pair of recti
?ers, a resonant signal input circuit, tuned to a
desired signal frequency, coupled to one recti?er,
a second signal input circuit, tuned to said de
sired frequency coupled to the second recti?er,
the selectivity at the second circuit being great
er, means for impressing signals on said signal
10 circuits, means responsive to current ?ow in
said one recti?er for preventing current flow in
the second recti?er until the signal amplitude
at the second input circuit attains a desired value,
means responsive to current flow in the second
15 recti?er for controlling the operation of said ?rst
means, and a signal amplitude limiter connected
across said ?rst resonant input circuit.
'7. In combination with the adjustable tuner
element of a radio receiver, means to control
20 adjustment of the tuner element, a control net
work for said means comprising a pair of recti
?ers, a resonant signal input circuit, tuned to a
desired signal frequency, coupled to one recti?er,
a second signal input circuit, tuned to said desired
25 frequency coupled to the second recti?er, the se
lectivity at the second circuit being greater,
means for impressing signals on said signal cir
cuits, means responsive to current ?ow in said
one recti?er for preventing current flow in the
30 second recti?er until the signal amplitude at the
second input circuit attains a desired value, and
means responsive to current ?ow in the second
recti?er for controlling the operation of said ?rst
means, said tuner element having a metallic
35 member operatively associated therewith, said
adjustment control means including a device
which acts as a magnet on said member when
energized.
8. In combination with the adjustable tuner
40 element of a radio receiver, means to control
adjustment of the tuner element, a control net
work for said means comprising a pair of recti
?ers, a resonant signal input circuit, tuned to a
desired signal frequency, coupled to one recti?er,
a second signal input circuit, tuned to said de
sired frequency coupled to the second recti?er,
the selectivity at the second circuit being greater,
means for impressing signals on said signal cir
cuits, means responsive to current ?ow in said
one recti?er for preventing current ?ow in the
second recti?er until the signal amplitude at the
second input circuit attains a desired value,
means responsive to current ?ow in the second
recti?er for controlling the operation of said ?rst
55
means, and each of said recti?ers being a diode,
the diodes having a common cathode.
9. In combination with the adjustable station
tuning element'of a superheterodyne receiver, an
intermediate frequency energy network, a recti
?er coupled thereto vto rectify signal energy in
said network, a second recti?er having an inter
mediate frequency input circuit which has a
higher degree of selectivity than the ?rst net
work, means for coupling the latter to said sec 10
ond recti?er input circuit, means responsive to
current flow in the ?rst recti?er for preventing
recti?cation by the second recti?er until the
signal amplitude at the input circuit thereof ex
ceeds a predetermined amplitude, and means re 15
sponsive to the recti?ed current output of the sec
ond recti?er for preventing adjustment of said
tuning element.
_
10. In combination with the adjustable sta
tion tuning element of a superheterodyne re 20
ceiver, an intermediate frequency energy net
work, a recti?er coupled thereto to rectify signal
energy in said network, a second recti?er hav
ing an intermediate frequency input circuit which
has a higher degree of selectivity than the ?rst 25
network, means for coupling the latter to said
second recti?er input circuit, means responsive
to current ?ow in the ?rst recti?er for preventing
recti?cation by the second recti?er until the sig
nal amplitude at the input circuit thereof exceeds 30
a predetermined amplitude, means responsive to
the recti?ed current output of the second recti
?er for preventing adjustment of said tuning ele
ment, an ampli?er including said network in its
space current circuit, and said ampli?er being 35
included in said last named means.
11. In combination with the adjustable sta
tion tuning element of a superheterodyne re
ceiver, an intermediate frequency energy network,
a recti?er coupled thereto to rectify signal energy 40
in said network, a second recti?er having an
intermediate frequency input circuit which has a
higher degree of selectivity than the ?rst net
work, means for coupling the latter to said second
recti?er input circuit, means responsive to cur 45
rent ?ow in the ?rst recti?er for preventing rec
ti?cation by the second recti?er until the signal
amplitude at the input circuit thereof exceeds a
predetermined amplitude, and means responsive
to the recti?ed current output of the second rec
ti?er for preventing adjustment of said tuning
50
element, said last means including an electron
discharge tube whose input electrodes are ener
gized by the second recti?er current output.
CAREL JAN VAN LOON.
55
Документ
Категория
Без категории
Просмотров
0
Размер файла
523 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа