U.S. patent number 3,714,575 [Application Number 05/061,945] was granted by the patent office on 1973-01-30 for code controlled broadcasting system.
This patent grant is currently assigned to Amalgamated Music Enterprises, Inc.. Invention is credited to Theodore Rogalski.
United States Patent |
3,714,575 |
Rogalski |
January 30, 1973 |
CODE CONTROLLED BROADCASTING SYSTEM
Abstract
A radio broadcasting system includes a transmitter which
transmits a program signal such as music on one channel, periodic
message signals such as advertising commercials on another channel
and a plurality of code signals of different frequencies occuring
in time at the beginning of selected ones of the message signals. A
plurality of radio receivers each receive the program, message and
code signals and include means for audibly reproducing the program
and message signals. Each receiver includes first and second
filtering means responsive to only the program or message signals,
respectively, together with switching means for connecting either
of the first and second filtering means in the receiver circuit.
Each receiver also includes a control circuit operative in response
to the presence of a particular one of the code signals to cause
movement of the switching means from one of the filters to the
other. The control circuit includes feedback adjusting means in the
frequency responsive input portion thereof, a high resistance
coupling from input to output, and time delay means associated
therewith which together assure that receiver operation is switched
from program to message signal reproduction only in response to the
particular intended code signal and not in response to other
control signals closely spaced in frequency or to transient or
spurious signals.
Inventors: |
Rogalski; Theodore (Buffalo,
NY) |
Assignee: |
Amalgamated Music Enterprises,
Inc. (Syracuse, NY)
|
Family
ID: |
22039182 |
Appl.
No.: |
05/061,945 |
Filed: |
August 7, 1970 |
Current U.S.
Class: |
455/526;
455/701 |
Current CPC
Class: |
H04H
20/31 (20130101) |
Current International
Class: |
H04H
1/00 (20060101); H04h 001/04 () |
Field of
Search: |
;325/51,53,54,55,57,64,392,466,308 ;179/15BT,15FD ;340/311
;343/200,228 ;330/21,26,31 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Safourek; Benedict V.
Claims
I claim:
1. A radio broadcasting system comprising:
a. a transmitter for transmitting a program signal on one channel
and periodic message signals on another channel;
b. coding means in said transmitter for generating plurality of
code signals, each of a different frequency, and corresponding in
time to the beginning of selected ones of the message signals;
c. a plurality of radio receivers, each of said receivers normally
audibly reproducing said program signal and each including means
for switching operation to audibly reproduce said message signals
and then switching operation thereof to resume reproduction of said
program signal;
d. control means in each of said receivers operative in response to
only a particular predetermined one of said code signals and
connected to said switching means for switching operation of said
receiver to audibly reproduce said message signal upon the
occurrence of said particular one of said code signals, said
control means including frequency responsive circuit means tuned to
the frequency of said particular code signal and having means for
providing a constant voltage at the output of said frequency
responsive circuit means in response to the presence of said
particular code signal frequency, rectifier means connected to the
output of said frequency responsive circuit means, and a high
resistance path connecting the output of said rectifier means to
transducer means, and
e. each of said receivers including first and second speaker means
connected to the output thereof and wherein said apparatus includes
means responsive to the presence of said message signal and to the
operation of said control means for disconnecting one of said first
or second speaker means from the output of said receiver for the
duration of said message signal.
2. Apparatus according to claim 1 wherein each of said receivers
includes a first filter means for passing said program signal and
rejecting said message signal, second filter means for passing said
message signal and rejecting said program signal, switching means
being connected in controlled relation to said control means for
placing one of said filter means into operation in said receiver in
response to the operation of said control means.
3. Apparatus according to claim 2 wherein said first filter means
normally is in operation in said receiver and wherein said
switching means removes said first filter means from operation and
places said second filter means into operation in said receiver in
response to the operation of said control means.
4. Apparatus according to claim 1 wherein the duration of each of
said code signals is relatively much shorter than the duration of
said message signals and wherein said control means includes
holding circuit means for maintaining operation of said control
means in response to the presence of said message signal and for
the duration of said message signal.
5. Apparatus according to claim 1 wherein said control means
includes timing means whereby the duration of said code signal must
be greater than the time constant of said timing means for
operation of said control means to be maintained.
6. In a radio broadcasting system wherein a transmitter transmits a
program signal on one channel, periodic message signals on another
channel, and a plurality of code signals of different frequencies
and occurring in time at the beginning of selected ones of the
message signals, a radio receiver comprising:
a. means for detecting the program, message and code signals;
b. means for audibly reproducing the program and message
signals;
c. first filtering means connected to said reproducing means for
passing the program signal and rejecting the message signal;
d. second filtering means connected to said reproducing means for
passing the message signal and rejecting the program signal;
e. switching means for connecting either of said first or second
filtering means to said detecting means; and
f. frequency responsive control circuit means including a resonant
circuit having an input and an output and tuned to the frequency of
a particular one of said code signals, means for connecting the
input of said resonant circuit directly to the output of said
receiver detecting means, transducer means having an output
operatively connected to said switching means, said control circuit
means having means coupling the output of said resonant circuit to
said transducer means with a horizontal frequency response at the
frequency of said particular code signal so that the signal applied
to said control circuit means must correspond in frequency
precisely with the frequency to which said resonant circuit is
tuned in order to operate said transducer means thereby causing
movement of said switching means from said first filtering means to
said second filtering means in response to the presence of only
said particular one of said code signals.
7. A radio receiver according to claim 6 wherein said switching
means normally connects the output of said detecting means to the
input of said first filter means and is moved to the input of said
second filter means in response to the operation of said control
circuit means.
8. A radio receiver according to claim 6 wherein the duration of
each of said code signals is relatively much shorter than the
duration of said message signals and wherein said control circuit
means includes holding circuit means coupled to said reproducing
means for maintaining operation of said control circuit means for
the duration of said message signal.
9. A radio receiver according to claim 6 wherein said control
circuit means includes timing means whereby the duration of said
code signal must be greater than the time constant of said timing
means for operation of said control means to be maintained.
10. A radio receiver according to claim 6 including first and
second speaker means connected to the output thereof and further
including means responsive to the presence of said message signal
and to the operation of said control circuit means for
disconnecting one of said first or second speaker means from the
output of said receiver for the duration of said message
signal.
11. A radio receiver according to claim 6 wherein said means
coupling the output of said resonant circuit to said transducer
means comprises:
a. first amplifier means having an input and an output;
b. means including a variable capacitor for connecting the output
of said resonant circuit to the input of said amplifier;
c. rectifier means coupled to the output of said amplifier
means;
d. second amplifier means having an input and having an output
connected to said transducer means; and
e. a high resistance path connecting said rectifier means to said
input of said second amplifier means.
12. In a radio broadcasting system wherein a receiver includes
first and second transmission means to be in operation during
corresponding first and second modes of reception and switching
means for connecting the receiver detecting means selectively to
either of said transmission means, a control circuit for operating
said switching means in response to the reception of a particular
code signal, said control circuit comprising:
a. a resonant circuit having an input and an output and tuned to
the frequency of said particular code signal;
b. means connecting the input of said resonant circuit to the
output of said receiver detecting means;
c. first amplifier means having an input and an output;
d. means including a variable capacitor for connecting the output
of said resonant circuit to the input of said amplifier;
e. rectifier means coupled to the output of said amplifier
means;
f. second amplifier means having an input and an output;
g. a high resistance path connecting said rectifier means to said
input of said second amplifier means;
h. capacitive timing means connected to the input of said second
amplifier means whereby the duration of said code signal must be
greater than the time constant of said timing means for operation
of said control circuit to be maintained;
i. means for coupling said output of said second amplifier means to
said switching means whereby the latter is moved in response to
operation of said second amplifier means; and
j. holding circuit means coupled to one of said first and second
transmission means and to the input of said second amplifier means
for maintaining operation of said control circuit for the duration
of one of said modes of reception upon cessation of said code
signal.
13. A control circuit according to claim 12 wherein said means
connecting the input of said resonant circuit to the output of said
detecting means comprises the series combination of first and
second diodes connected in opposed relation.
14. A control circuit according to claim 12 wherein said first
amplifier means comprises a triode, wherein said means including
said variable capacitor is connected between said resonant circuit
and the grid of said triode, and wherein said means further
comprises a fixed capacitor connected to said variable capacitor
and means connecting the junction of said fixed capacitor and said
variable capacitor to the cathode of said triode.
15. In a radio broadcasting system wherein a receiver includes
first and second transmission means to be in operation during
corresponding first and second modes of reception and switching
means for connecting the receiver detecting means selectively to
either of said transmission means, a control circuit for operating
said switching means in response to the reception of a particular
code signal, said control circuit comprising:
a. a resonant circuit having an input and an output and tuned to
the frequency of said particular code signal;
b. means including a variable capacitor connecting the input of
said resonant circuit to the output of said receiver detecting
means;
c. a field effect transistor having a gate terminal and an output
terminal, said gate terminal being connected to the output of said
resonant circuit;
d. amplifier means having an input and an output, said input being
connected to said transistor output terminal,
e. rectifier means coupled to the output of said amplifier
means;
f. transducer means having an input and an output;
g. a high resistance path connecting said rectifier means to said
input of said transducer means; and
h. means for coupling said output of said transducer means to said
switching means whereby the latter is moved in response to a signal
on said input of said transducer means.
Description
BACKGROUND OF THE INVENTION
The present invention relates to radio broadcast systems, and, more
particularly, to a system including a single transmitter and a
plurality of receivers for broadcasting a program on one channel to
all receivers and periodic messages on another channel to selected
ones of the receivers, selection being accomplished by coded tones
generated along with the particular messages.
One area of use of the present invention is in the broadcasting of
background music simultaneously to a large number of business
establishments for the pleasure of the customers therein and
interrupting the music periodically with speech messages, such as
advertising, at selected ones of groups of establishments to
provide the customers with information. In recent times there has
been a significant growth in the broadcasting of background music
to business establishments such as supermarkets or banks. The
geographic area included within the normal broadcast range of
available equipment generally will contain several supermarket
chains each having a considerable number of branches, or likewise,
several banks each having a large number of branches. The
proprietor or manager of each establishment would like to interrupt
the music periodically and substitute an advertising message. With
equipment heretofore available, this of course can be done at each
location by turning off the broadcast equipment and by using
separate audio equipment to broadcast the commercial.
It would, therefore, be highly desirable to provide a radio system
with the capability of broadcasting background music along with
periodic commercial messages, the commercial being received by
selected ones of the receivers and selection be accomplished by
coded control signals. One requirement which is immediately
apparent is proper routing of commercial messages to the various
receivers because of the obvious undesirability of having an
advertising message intended for one establishment being improperly
received by an entirely different establishment. Such a system
might be constructed so that any failure in the portion thereof
which provides the routing of messages would result in continued
transmission of the music rather than improper routing of the
messages. In addition, the larger the number of radio receivers in
a given system the closer will be the frequency spacing between the
coded control signals thus making more difficult the design of the
control signal responsive portions thereof. In particular, that
portion of the receiver must have a high degree of sensitivity
whereby it causes switching of receiver operation from program to
message reception only in response to the occurrence of a
particular one of the code signals.
SUMMARY OF THE INVENTION
The present invention provides a radio broadcast system wherein
there is transmitted from a single transmitting station a program
signal such as music at a first frequency, periodic message signals
such as commercials at a second frequency, and a plurality of code
signals at different frequencies and occurring in time in
correspondence with the beginning of selected ones of the message
signals. Each of a plurality of receivers normally audibly
reproduces the program signal and is provided with a frequency
responsive control circuit which in response to the occurrence of a
selected one of the code signals switches the receiver operation to
audible reproduction of a message signal. The frequency responsive
control circuit for each receiver is constructed in a manner such
that it has a high degree of sensitivity to insure that it provides
switching only in response to a particular one of the code
signals.
While several specific embodiments of the principles of the present
invention are illustrated in the accompanying drawing and described
in detail in the following specification, it is to be understood
that such embodiments are by way of example and that various
mechanical modifications may be made without departing from the
spirit of the invention, the scope of which is limited only as
defined in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a radio broadcasting system of the
present invention;
FIG. 2 is a block diagram of one of the receivers included in the
system of FIG. 1 according to the present invention;
FIG. 3 is a schematic diagram of a control circuit according to the
present invention included in the receiver of FIG. 2;
FIG. 4 is a block diagram of an alternative embodiment of a
receiver included in the broadcasting system of the present
invention;
FIG. 5 is a schematic diagram of a speaker selection control
circuit included in the receiver of FIG. 4; and
FIG. 6 is a schematic diagram of an alternative embodiment of the
control circuit shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A radio broadcasting system according to the present invention
includes a single transmitting station and a plurality of radio
receivers for broadcasting a program, such as background music, on
one channel to all receivers and periodic messages, such as
commercials, on another channel to selected ones of the receivers.
Selection is accomplished by generating coded tone signals along
with the messages according to which receiver is intended to
receive a particular message, the receivers, in turn, being
provided with control means responsive to particular ones of the
code signals. Referring now to the block diagram of FIG. 1, the
broadcasting system of the present invention includes a
transmitter, designated generally at 10, for transmitting from an
antenna 11 a program signal on one channel and periodic message
signals on another channel. The standard transmitter mixer and
output amplification stages are represented by block 12, the output
of which is connected to antenna 11. Connected to the input of
transmitter stages 12 are a program signal source 13, a message
signal source 14, and a coding means 15 as shown in FIG. 1. In a
particular application of the present invention the program signal
consists of music, and block 13 thus would represent a conventional
record player or tape recorder having the acoustical output signal
thereof converted and translated through a noise suppressor,
preamplifier and automatic volume control and applied to the input
of the mixer included in block 12. In this same application the
message signal consists of speech such as commercial messages and,
therefore, block 14 would include a tape recorder or microphone
having the acoustical output signal thereof translated through an
amplifier to the input of the mixer included in block 12. A coding
means 15 also is included in transmitter 10 for generating a
plurality of coded tone signals, each of a different frequency,
which occur in time at a point corresponding to the beginning of
selected ones of the message signals from block 14. The code
signals from coding means 15 are applied to the input of the mixer
in transmitter stage 12, and each of the signals has a duration
relatively much shorter than the normal duration of the periodic
message signals provided by block 14.
In operation, the main carrier of transmitter 10 can be frequency
modulated into two subcarriers corresponding to the program and
message signals. Preferably, transmission of the program signal is
at 67 kilocycles although a variation within the range of 59 to 75
kilocycles is not objectionable. Similarly, transmission of the
message signals can be within the range of 37 to 47 kilocycles with
transmission at 42 kilocycles being preferred. A plurality of code
signals can be generated in the range of 20 to 35 kilocycles, with
particular ones of the code signals occurring in time at a point
corresponding to the beginning of particular ones of the message
signals. In one illustrative example, 19 code signals are generated
within the foregoing prescribed range, and the frequency spacing
was logarithmic wherein the spaces have a magnitude of 0.5
kilocycle in the lower portion of the range and a spacing of 1.0
kilocycle in the upper portion of the range. In addition, each of
the code signals preferably has a duration of about three
seconds.
Inasmuch as radio transmitter stations similar to the one described
herein are readily familiar to those skilled in the art, the
foregoing description is believed to be in sufficient detail.
Equipment for taping messages and for recording the desired coded
tones or signals on the tape alongside the message under control of
a manually operated selector is readily commercially available for
use in such radio transmitter stations.
The radio broadcasting system of the present invention further
includes a plurality of radio receivers 20, and each receiver 20
has an antenna 21. In addition, the receivers 20 are of
substantially identical construction as indicated by the use of the
prime superscripts in FIG. 1. Each receiver 20 normally audibly
reproduces the program signal from transmitter 10 and is adapted to
also audibly reproduce the message signal from transmitter 10 upon
switching of the receiver mode of operation. Each receiver is
provided with control means responsive to a particular code signal
from transmitter 10 for switching receiver operation and thereby
resulting in audible reproduction of the message signal as will be
described in detail hereafter. A preferred use of the system of
FIG. 1 is in broadcasting background music to business
establishments for convenience of the customers therein and for
broadcasting periodic messages, such as commercials, to selected
ones of the receivers. To this end a single radio receiver 20 can
be located in one establishment and provided with several speakers
positioned around the area in which the customers normally are
present. A number of different establishments can be serviced by
the present system to be provided with the same background music
but with different commercial messages, the number being equal to
the number of code signals generated by transmitter 10. It also
will be appreciated that the same commercial message is likely to
be broadcast to all of the branches of a particular retain chain,
and therefore the total number of receivers included in the system
would be greater than the number of code signals. In other words,
the capacity of transmitter 10 in terms of the number of code
signals which can be provided is the constraint on the number of
different commercial messages which can be transmitted in the
system. The number of receivers for which the same commercial
message is intended is limited only by geographic considerations
and the radiation capability of transmitter 10.
A preferred form of receiver 20 for use in the broadcast system of
the present invention is shown in the block diagram of FIG. 2. The
other receivers for use in the system are identical in construction
to receiver 20 shown in FIG. 2 with the exception that the
frequency responsive portion of each is adjusted or modified so as
to be activated by a particular one of the code signals from
transmitter 10 as will be explained in detail hereafter. Referring
now to FIG. 2, receiver 20 includes means for detecting the
program, message and code signals from transmitter 10 comprising an
antenna 21, connected to the input of a radio frequency amplifier
and oscillator-mixer stage 22, the output of which is translated
through an intermediate frequency amplifier stage 23 to the input
of a limiter and discriminator stage 24. The program and message
signals are audibly reproduced by means including audio amplifier
stage 25, the output of which is connected to the input of each of
a plurality of speakers designated 26 in FIG. 2. The stages of
receiver 20 described so far are those of a standard or
conventional radio receiver, and one receiver found readily
adaptable for use in the present invention is available
commercially under the designation Browning CRA.
In accordance with this invention, receiver 20 is adapted to
normally audibly reproduce the program signal, but to be switched
in operation to audibly reproduce the message signal when a
particular one of the code signals from transmitter 10 activates a
control means in receiver 20. Referring again to FIG. 2, receiver
20 also includes a first filtering means 27 for passing the program
signal and rejecting the message signal. For convenience in
illustration, filter means 27 is labeled with the frequency F.sub.A
which is that of the program signal. The output of filter 27 is
connected to the input of audio amplifier 25 through line 28 and a
circuit designated 29 in FIG. 2. Circuit 29 includes conventional
subcarrier amplifier, demodulator and squelch circuits. Receiver 20
further includes a second filtering means 31 for passing the
message signal and rejecting the program signal. For convenience in
illustration, filter 31 is labeled with the frequency F.sub.B which
is that of the message signal. The output of filter 31 is connected
to the input of audio amplifier 25 through a line 32 and also
through circuit 29.
Receiver 20 further includes switching means, designated generally
at 34, for connecting either of the first or second filtering means
27 and 31, respectively, to the receiver detecting means, in
particular to line 35 connected to the output of limiter and
discriminator stage 24. Receiver 20 finally comprises a control
circuit 36 responsive to a particular one of the code signals from
transmitter 10 and which signal appears at the output of the
receiver detecting means for moving switching means 34 to cause
receiver 20 to audibly reproduce the message signal upon the
occurrence of that code signal. The input of control circuit 36 is
connected by means of a line 37, which in turn is connected to line
35, to the output of receiver limiter and discriminator stage 24.
The output of control circuit 36 is operatively connected to
switching means 34 as indicated by the dashed line 38 in FIG. 2 and
which will be described in more detail hereafter. The subcarrier
amplifier in circuit 29 is connected through line 39 to control
circuit 36 to establish a holding circuit therein as will be
described in detail hereafter.
FIG. 3 shows in detail one form of control circuit 36 constructed
in accordance with this invention. Control circuit 36 comprises an
amplifier including a triode 45 the output of which is rectified
and coupled through a high resistance network to an
electromechanical transducer for converting signals provided by
circuit 36 into mechanical movement to operate switching means 34.
Triode 45 has cathode, grid and plate terminals 46-48,
respectively. The input of triode amplifier 45 is coupled to line
37, which is connected to the input of circuit 36, in the following
manner. A tapped capacitance comprising the series combination of
fixed capacitor 49 and variable capacitor 50 is connected between
the input of amplifier 45 and ground. In particular, one terminal
of fixed capacitor 49 is connected to grid terminal 47 of triode
45, and one terminal of variable capacitor 50 is connected to
ground. The junction of capacitors 49 and 50 is connected by means
of lead 51 to cathode terminal 46 of triode 45 and through a
cathode resistor 52 to ground. An LC frequency responsive circuit
53 is connected across the series combination of capacitors 49 and
50. In particular, circuit 53 comprises an inductor 54 connected in
parallel with the series combination of capacitors 55 and 56. The
values of the components of circuit 53 are selected so that it is
responsive to the frequency of a particular one of the coded tone
signals generated by transmitter 10. The junction of capacitors 55,
56 is connected to the input terminal of circuit 36, here
designated 36a, through a resistor 57 and the series combination of
diodes 58, 59. Diodes 58, 59 are connected in opposed or
back-to-back relation wherein the cathode of diode 58 is connected
to resistor 57, the anodes of the diodes are connected together,
and the cathode of diode 59 is connected to the input terminal 36a
which, in turn, is connected to lead 37.
The output of triode amplifier 45 is rectified and coupled through
a high resistance circuit to an electromechanical transducer at the
output of control circuit 36. In particular, plate terminal 48 of
triode 45, which also is connected through a resistor 60 and a lead
61 to a standard B+ voltage source, is connected through the series
combination of a resistor 62 and capacitor 63 to the input of a
full-wave rectifier comprising diodes 64 and 65. The anode of diode
64 is connected to one terminal of capacitor 63 and to the cathode
of diode 65. Diode 65 is suitably biased by means of a lead 66
connecting the anode thereof to the wiper arm of a potentiometer 67
connected across a source of negative bias voltage 68. A full-wave
rectified signal in the form of a square wave is developed across a
voltage divider comprising resistors 69, 70 and 71 and is applied
to the input of a triode amplifier 72. Triode 72 has cathode, grid
and plate terminals 73-75, respectively. Grid terminal 74 is
connected to resistor 71 and through a capacitor 76 to ground.
Cathode terminal 73 of triode 72 is connected directly to ground,
and the output signal from amplifier 72 appears on plate 75, which
is connected to one terminal of a relay winding 77, the other
terminal of which is connected through a lead 78 to a standard B+
voltage source. It is apparent, therefore, that an output signal
from triode amplifier 72 causes energization of relay winding 77
which, in turn, provides a mechanical movement which is transmitted
through the coupling indicated by the dashed line 38 to the arm of
the switching means designated 34 in FIG. 2. It should also be
apparent that other types of signal responsive switching means can
be connected to the output of control circuit 36, such as to the
output of amplifier 72, for switching the operation of receiver 20
from one of the filters 27, 31 to the other without departing from
the spirit and scope of the present invention.
According to a preferred mode of the present invention, the coded
tone signals will have a relatively short time duration, preferably
about three seconds, which is significantly less than the duration
of typical message signals broadcasted in the present system.
Control circuit 36, therefore, is constructed to include a holding
circuit for maintaining receiver 20 in a switched condition from
one filter to the other upon the occurrence of a selected code
signal for as long as the intended message signal is present.
Referring again to FIG. 3, it is seen that a switch 80 is included
with one fixed contact 81 connected to the junction of resistors 69
and 70, and with a movable contact arm 82 normally engaging fixed
contact 81 and mechanically coupled to relay winding 77 as
indicated by the dashed line 83. A second fixed contact 84 of
switch 80 is connected through a resistor 85 to one terminal of a
coupling capacitor 86, the other terminal of which is connected to
lead 39. It will be recalled from the discussion of the system of
FIG. 2 that lead 39 is connected to the subcarrier amplifier in
circuit 29 where the message signal will be available. A half-wave
rectifier comprising diode 87 is connected to the junction of
resistor 85 and capacitor 86, the cathode of diode 87 being
connected to the junction, and diode 87 is suitably biased by
virtue of the connection of the anode thereof to potentiometer 67
and negative bias source 68. A resistor 88 is connected in parallel
with diode 87.
The broadcasting system of FIGS. 1-3 operates in the following
manner. Transmitter 10 transmits from antenna 11 a program signal
on one channel, for example at a frequency of 67 kilocycles, which
is intended for continuous transmission to each of a plurality of
receives 20, as indicated in FIG. 1. The program signal, for
example, can consist of background music which is broadcast to a
large number of business establishments such as supermarkets or
banks. Transmitter 10 also periodically will broadcast message
signals intended for only selected ones of the receivers, selection
being accomplished by the transmission of code signals by
transmitter 10 at a time corresponding to the beginning of
particular message signals. The message signals are broadcast on a
second channel, for example at a frequency of 42 kilocycles, and
advantageously can consist of advertising or other messages for the
purpose of informing customers at particular establishments.
Each of the receivers 20 shown in the system of FIG. 1 operates in
the following manner. Referring now to FIG. 2, switching means 34
normally is in the position shown in FIG. 2 whereby filter 27,
which passes only the program signal, is connected in the
transmission path of receiver 20, and filter 31 is therefore
switched out of the circuit. The program signal from transmitter 10
is received by antenna 21 and translated through receiver stages
22-24 in a conventional manner, whereupon it is applied to the
input of filter 27. Filter 27 is responsive to the frequency of the
program signal, for example 67 kilocycles, and functions to pass
that signal but to reject all other signals such as message signals
or code signals. The output of filter 27 is applied through line 28
to the input of circuit 29 which in turn is connected to the input
of an audio amplifier 25. The squelch circuit in circuit 29 is of
known construction and functions to mute the signal transmitted to
audio amplifier 25 should the signal from filter 27 decrease in
amplitude below a desired level. The program signal is audibly
reproduced and available at the output of the various speakers 26,
which would be placed at spaced locations around the business
establishment. Thus, during this mode of operation customers in the
establishment would hear music in the background for their pleasure
and enjoyment.
Each receiver 20 has the capability of switching from the program
signal to a mode of operation wherein it audibly reproduces a
message signal. It is important to note, however, that reception of
a particular message signal is only by a selected one or ones of
receivers 20, and while that happens the remaining receivers in the
system will continue to receive the program signal such as
background music. Assume that the receiver shown in FIG. 2 has been
receiving and audibly reproducing the aforementioned program signal
and that it is now about to receive and audibly reproduce a message
signal intended for it and for a relatively short period of time
whereupon the receiver will return to its original mode of
operation wherein it reproduces the program signal. For a
particular receiver 20 to reproduce a message signal two conditions
must be met. A first condition is, of course, that the message
signal be received by antenna 21, and a second condition is that
the one discrete code signal intended for that receiver which will
activate control circuit 36 is present also at antenna 21 and
simultaneous with the beginning of the message signal.
The program, message and code signals are translated through
receiver stages 22-24, and are applied simultaneously to the inputs
of filter 27 through switching means 34 and of control circuit 36
through line 37. Assuming that the present code signal is the
particular one which will activate circuit 36, switching means 34
is moved from the position shown in FIG. 2 to the dotted line
position whereupon line 35 is connected to the input of filter 31.
Filter 31, in turn, functions to pass the message signal which, for
example, has a frequency of 42 kilocycles, but to reject the
program signal. The output of filter 31 is applied through line 32
to the input of circuit 29 and then through audio amplifier 25 and
speakers 26, whereby the message such as a commercial is audibly
reproduced. The continued transmission of the message signal
through filter 31 for a predetermined time also completes a holding
circuit conditioned by the operation of circuit 36 and indicated
generally by means of line 39 in FIG. 2, to maintain operation of
control circuit 36 and hence switching means 34 in the position
shown whereby the detected signals are applied to the input of
filter 31 for the duration of the message signal. The code signal
has a duration relatively much shorter than that of the message
signal, and according to a preferred mode of the present invention
the code signal lasts for about 3 seconds. Also, the code signal
must be present for this duration of 3 seconds to develop a voltage
level sufficient to maintain operation of control circuit 36 and
hold switching means 34 in this position.
The requirement that the code signal be present for a predetermined
time, here about 3 seconds, together with the fact that circuit 36
must first be operated before the holding circuit can be
established prevents inadvertent switching of receiver operation in
response to transient or spurious signals as will be described in
more detail hereafter. Thus, during this mode of operation the
background music or the program signal is temporarily interrupted
at a particular receiver(s) and there is substituted an informative
message such as a commercial. At the conclusion of the message, the
receiver switches back to operation whereby the background music
again is audibly reproduced because upon cessation of the message
signal the aforementioned holding circuit is broken causing
switching means 34 to return to its normal position as indicated in
FIG. 2.
The broadcasting system of the present invention has several
advantageous characteristics. The normal mode of operation of each
receiver 20 in the broadcasting system is with switching means 34
in the position shown in FIG. 2 whereby the receiver 20 audibly
reproduces the program signal. Switching of the receiver from
audible reproduction of the program signal to audible reproduction
of a message signal occurs only upon satisfaction of two
conditions: the availability of a message signal and the
simultaneous occurrence of a particular one of the code signals
intended for that receiver. In addition, the time requirement on
the code signal for operating circuit 36 prevents switching in
response to transient or other spurious signals. Therefore, any
malfunction in operation of either transmitter 10 or receiver 20
most likely will result either in continued reception of the
program signal or cessation of receiver operation altogether. In
other words, unintended switching of any receiver to reproduction
of a message signal not intended for it will not occur in the
system of the present invention. This is of considerable importance
when receivers 20 are located respectively in different commercial
establishments, and the advertising messages intended for one or
more establishments would be completely foreign to and undesirable
in any of the remaining establishments. In addition, the
broadcasting system of the present invention has the capability of
transmitting from a single receiver both a program signal
consisting of background music and message signals consisting of
periodic commercials. There is, as a result, no need to provide
separate public address systems at each commercial establishment to
provide periodic commercials upon temporary interruption of the
background music. All that is required at each establishment is a
single receiver with one or more speakers operatively connected
thereto as shown in FIG. 2, which receiver is modified according to
the present invention to include filters 27 and 31, together with
control circuit 36.
The operation of control circuit 36, which was described briefly in
the foregoing discussion of the overall system operation, now will
be described in more detail. Referring to FIG. 3, the output of
receiver limiter and discriminator stage 24 comprises the detected
program, message and code signals and is applied through lead 37 to
the input of circuit 36. These signals, in turn, are transmitted
through diodes 58, 59 and resistor 57 to the input of tuned circuit
53. Circuit 53 is responsive to the frequency of only one of the
plurality of code signals transmitted from transmitter 10, and upon
the presence of that particular code signal, circuit 53 resonsates
to provide a signal to the input of amplifier 45. The amplified
signal then is full-wave rectified by diodes 64 and 65 resulting in
a square wave signal across the divider network comprising
resistors 69-71 which signal is applied to the input of amplifier
72. The output of amplifier 72, in turn, energizes relay coil 77 to
move switching means 34 shown in FIG. 2 to the position whereby the
line 35 is connected to the input of filter 31. The energization of
relay winding 77 also causes movement of switch arm 82 away from
contact 81 and into engagement with contact 84. A circuit thus is
completed from line 39, which is connected to filter 31, through
capacitor 86, resistor 85, and resistor 71 to the input of
amplifier 72.
The message signal present at the subcarrier amplifier in circuit
29 is transmitted through line 39, half-wave rectified by diode 87,
and is applied to the input of amplifier 72. The message signal is
of sufficient amplitude so as to require only half-wave
rectification as provided by the single diode 87. The rectified
code signals of 3 seconds duration will have charged timing
capacitor 76, and the voltage thereon is applied through tube 72 to
energize relay winding 77. The time constant for this mode of
operation is determined by the magnitudes of resistors 69 and 71
and capacitor 76 and is made the duration of the code signal, here
three seconds, which is significantly greater than the duration of
any transient or spurious signals which might be present in the
system. This, in turn, prevents inadvertent switching of receiver
operation from program to message signal reproduction in response
to transient or spurious signals. Were no signal present on line
39, relay 77 would drop out within three seconds because of the
discharge of capacitor 76 through resistors 71 and 85, the time
constant determined by the values of these three elements. Assuming
a signal is present on line 39, however, amplifier 72 will continue
to provide an output signal to energize winding 77 for the duration
of the message signal transmitted through filter 31. Upon cessation
of the message signal on line 39, capacitor 76 discharges and
amplifier 72 no longer provides an output thereby de-energizing
winding 77 with the result that switching means 34 in FIG. 2
returns to its normal position engaging contact arm 81.
When a relatively large number of receivers are included in the
system of the present invention and when the code signals are
relatively closely spaced in frequency, it is apparent that circuit
36 should have a flat or horizontal rather than an oblique or
inclined frequency-voltage characteristic, so as to have a high
degree of sensitivity. In other words, were circuit 36 to have an
inclined frequency-voltage characteristic, code signals varying
slightly in frequency from the discrete code signal frequency to
which it is tuned could cause circuit 36 to provide an undesired
output signal. On the other hand, with a horizontal characteristic,
the input signal must correspond in frequency precisely with the
frequency to which circuit 53 is tuned so that a square wave of
sufficient amplitude is developed for application to the input of
amplifier 72. Otherwise the occurrence of an adjacent tone signal
might cause an output signal to be generated by circuit 36, due to
the inclined nature of the characteristic, and cause energization
of relay 77 and an undesired switching from program to message
signal reproduction.
Various features of circuit 36 contribute to the high degree of
sensitivity between frequency and output voltage. The relatively
loose degree of coupling provides a sharp frequency response. The
provision of diodes 58 and 59 connected back-to-back in series with
the input of tuned circuit 53, together with resistors 62, 69 and
70 having relatively large magnitudes place relatively little load
on the operation of tube 45. The tapped capacitance comprising
fixed capacitor 49 and variable capacitor 50 connected to the input
of tube tube 45 provides automatic feedback control wherein
capacitor 49 equalizes the feedback to maintain a constant voltage
in the tube plate circuit. Capacitor 50 is varied in magnitude to
adjust the feedback in the circuit of tube 45 to compensate for
manufacturing tolerances in the magnitudes of inductor 54 and
capacitors 55, 56 of tuned circuit 53 and thus permit relatively
precise tuning to a desired code signal.
According to a preferred mode of the present invention, various
components of control circuit 36 have the following ratings or
magnitudes:
Resistor 57 - 0.47 M
Capacitor 49 - 470 uuf
Capacitor 50 - 0-680 uuf
Resistor 62 - 0.47 M
Capacitor 63 - 300 uuf
Resistor 69 - 22 M
Resistor 70 - 10 M
Resistor 71 - 22 M
Capacitor 76 - 0.1 uf
Resistor 85 - 22 M
Capacitor 86 - 300 uuf
Diodes 58, 59 - 1N64
FIG. 4 illustrates a modification of each of the radio receivers
included in the broadcast system of FIG. 1 according to a second
embodiment of the present invention. In this embodiment the system
of the present invention operates to broadcast a program signal to
the public areas of a business establishment and periodic message
signals only to a private area. Selection among a plurality of
receivers is provided by the generation of coded tone signals from
the transmitter. One advantageous use of the system according to
this embodiment would be for a bank having a large number of
branches, wherein it is desired to broadcast background music from
a single transmitting station to the public areas of all the
branches and periodic messages to only the manager's office,
employee area or other private area but not to the public area. As
in the system according to the first embodiment, this system has
the capability of transmitting different message signals to
different receivers by virtue of the generation of a plurality of
code signals, each of a different frequency, and of the inclusion
of a frequency responsive control circuit within each receiver as
will now be described in detail.
A receiver 100 constructed in accordance with this embodiment of
the present invention includes an antenna 101 connected to the
input of a radio frequency amplifier and oscillator-mixer stage
102, the output of which is translated through an intermediate
frequency amplifier stage 103 to the input of a limiter and
discriminator stage 104. The program and message signals available
at the output of limiter and discriminator stage 104 are audibly
reproduced by means of a subcarrier amplifier, demodulation and
squelch stage 105, the output of which is translated through an
audio amplifier 106, and applied through a switching means 107 to
each of a plurality of speakers designated 108 in FIG. 4. The
output of audio amplifier 106 is connected also through a line 109
to a speaker 110 for audibly reproducing message signals in an area
which is separate or private from that area in which speakers 108
are located. While only one speaker 110 is shown, additional
speakers could, of course, be connected to line 109. The foregoing
components of receiver 110 between antenna 101 and audio amplifier
106 are arranged in a standard or conventional manner, and one
receiver which was found to be readily adaptable to modification
according to the present invention is marketed under the commercial
designation Browning CRA.
According to the present invention, receiver 100 further includes a
first filtering means 111 for passing the program signal and
rejecting the message signal. In preferred form filter 111 is
constructed to pass a frequency of about 67 kilocycles, and for
convenience is designated F.sub.A in FIG. 4. The output of filter
111 is connected to the input of amplifier squelch and demodulation
state 105 through a line 112. Receiver 100 further includes a
second filter means 113 for passing the message signal and
rejecting the program signal. In preferred form filter 113 is
constructed to pass frequencies at about 42 kilocycles, and for
convenience is designated F.sub.B in FIG. 4. The output of filter
113 is connected to the input of squelch and demodulation stage 105
by means of a line 114. Receiver 100 further includes a switching
means 115 for connecting either of the filtering means 111, 113 to
the receiver detecting means. In particular, switching means 115 is
shown in its normal position connecting the input of filter 112
through line 116 to the output of limiter and discriminator stage
104.
Receiver 100 further includes a control circuit 117 having an input
connected to the output of the receiver detecting means, in this
particular illustration the connection being provided by line 118
connecting line 116 at the output of limiter and discriminator
stage 104 to the input of control circuit 117. Control circuit 117
also has an output operatively connected to switching means 115 as
indicated by the dashed line 119, whereby control circuit 117
causes movement of switching means 115 from one of the filters 111,
113 to the other filter in response to the presence on line 118 of
a particular one of the code signals from the station transmitter.
A holding circuit for control circuit 117 is provided including
line 120 connected thereto and to the subcarrier amplifier in stage
105.
Receiver 100 finally includes a speaker selection control circuit
121 having a first input connected through a line 122 to the line
joining receiver stages 105 and 106 and a second input connected
through a line 123 to line 120 connected to receiver stage 105. The
output of speaker selection circuit 121 is operatively connected to
switching means 107 as indicated by the dashed line 124 in FIG. 4.
Speaker selection circuit 121 functions, briefly, to move switching
means 107 and disconnect speakers 108 from the output of amplifier
106 in response to a signal to amplifier 106 applied through line
122 to one input of circuit 121 and to a signal from amplifier
squelch and demodulation circuit 105 applied through line 123 to
the other input of circuit 121. Speaker 110 remains connected
through line 109 to the output of audio amplifier 106 regardless of
whether switching means 107 is in its normal position as shown in
FIG. 4 or is moved therefrom in response to operation of circuit
121.
Receiver 100 shown in FIG. 4 represents one of a plurality of
similar receivers which can be substituted for the receivers 20 in
the system of FIG. 1. As in that system, there is transmitted to
receiver 100 from a single transmitting station a program signal,
such as background music, on one channel, periodic message signals
on another channel, and a plurality of code signals of different
frequencies and occurring in time at the beginning of selected ones
of the message signals. Receiver 100 operates in the following
manner. The program, message and code signals are detected by
antenna 101 and translated through the receiver stages 102-104.
Switching means 115 is in its normal position connecting line 116
to the input of filter 111, and in this mode of operation the
program signal, preferably at a frequency of 67 kilocycles, is
passed by filter 111 and audibly reproduced by receiver stages 105,
106 and speakers 108, 110. Switching means 107 in this mode of
operation is in a position connecting speakers 108 to the output of
audio amplifier 106, whereby the program signal, such as background
music, is audibly reproduced in both the public and private areas
of the business establishment.
Assume now that receiver 100 is detecting and reproducing the
program signal and there is transmitted to the receiver an intended
message signal along with the particular code signal to which
control circuit 117 will respond. The program, message and code
signals are available on line 116, and the code signal is applied
through line 118 to the input of control circuit 117, whereby the
latter by virtue of the connection indicated at 119 in FIG. 4
causes movement of switching means 115 from its normal position to
a position connecting line 116 to the input of filter 113. This
will occur, of course, only if the code signal is of sufficient
duration, such as three seconds, as in the case of control circuit
36. As a result, the program signal is no longer translated further
through the receiver and the message signal is passed by filter 113
to receiver stages 105 and 106. The presence of the message signal
in stage 105, and provided the code signal has the given duration,
establishes through line 120 a holding circuit for control circuit
117 for the duration of the message signal.
Speaker selection circuit 121 is operated in response to the
presence of the message signal on line 122 as will be explained,
and operation is maintained by virtue of the connection through
line 123. Selection circuit 121, in turn, through the operative
connection indicated at 124 in FIG. 4, causes movement of switching
means 107 from its normal position with the result that speakers
108 are disconnected from the output of audio amplifier 106.
Speaker 110, however, remains connected to the amplifier output
through the path provided by line 109. Speakers 108 remain
disconnected from amplifier 106 for the duration of the message
signal, and when the message signal is ended selection circuit 121
is deactivated and switching means 107 returned to its normal
position connecting the output of amplifier 106 to speakers
108.
Receiver 100, therefore, functions to audibly reproduce a program
signal, for example background music, simultaneously on two sets of
speakers, one of which can be placed in the public area of a
business establishment and the other in a private area. Receiver
100 functions further to audibly reproduce a message signal only on
the set of speakers in the private area, for example in the
manager's office of employee area of a bank. To this end, receiver
100 functions to disconnect the public area speakers from the
receiver circuit in response to the presence of both the message
signal and a particular code signal intended for that receiver. It
will be appreciated that while only one speaker 110 is shown in
FIG. 4, a plurality of similar speakers can be provided and
positioned at selected locations in the designated private area. It
should be apparent also that in a system including a large number
of receivers similar to receiver 100, each having a control circuit
117 responsive to a different one of the plurality of code signals
transmitted from the single station, a corresponding number of
different message signals can be transmitted and properly routed to
corresponding ones of the receivers where they are audibly
reproduced on the speaker such as speaker 110 in the selected
private area.
In a preferred form of receiver 100, filters 111 and 113 are
responsive to frequencies of 67 kilocycles and 42 kilocycles,
respectively, and thus are identical to filters 27 and 31,
respectively, of receiver 20. Likewise, control circuit 117 is
identical in construction to control circuit 36 shown in FIGS. 2
and 3. In particular, the holding circuit including line 120 is
conditioned by the operation of circuit 117, and the code signal on
line 118 must be present for at least a given time, such as three
seconds, to develop a voltage level sufficient to maintain the
holding circuit and switching means 115 in this position. In
addition, line 122 in the circuit of FIG. 4 connects an input of
selection circuit 121 to the output of stage 105 and line 123
connects another input to the subcarrier amplifier in stage
105.
A preferred form of speaker selection circuit 121 is shown in
detail in FIG. 5. Circuit 121 comprises an input amplifier
including a triode 130 having cathode, grid and plate terminals
131-133, respectively. Line 122 from the output of receiver stage
105 is coupled through a capacitor 139 to grid terminal 132 of
triode 130, and a tuned circuit comprising the parallel combination
of a capacitor 135 and an inductor 136 is connected between grid
terminal 132 and ground. Cathode 131 of triode 130 also is
connected to ground through a resistor 137. A suitable bias voltage
available on line 138 is applied through a resistor 139 to the
plate terminal 133 of triode 130. Circuit 121 further comprises an
output amplifier including a triode 145 having cathode, grid and
plate terminals 146-148, respectively. The output of amplifier 145,
available on plate terminal 148, is connected to one terminal of a
relay energizing winding 149, the other terminal of which connected
through a line 150 to a suitable source of bias voltage rated B+.
Relay winding 149 is mechanically coupled to switching means 107
shown in FIG. 4, as indicated by the dashed line 124. Energization
of winding 149 causes movement of switching means 107 away from its
normal position to thereby disconnect speakers 108 from line 109
connected to the output of audio amplifier 106.
The output of amplifier 130 is half-wave rectified and applied to
the input of amplifier 145 through a network comprising a coupling
capacitor 151, a diode rectifier 163, a resistor 152, a switch 153
including movable contact arm 154 and fixed contacts 155, 156, and
a resistor 157. Coupling capacitor 151 is connected to plate
terminal 133, switch arm 154 normally engages contact 155 thereby
connecting resistor 157 through resistor 152 to capacitor 151, and
a lead 158 connects resistor 157 to grid terminal 147 of triode
145. Grid terminal 147 also is connected to ground through a
capacitor 159. Relay winding 149 is mechanically coupled also to
switch 153 as indicated by the dashed line 160 in FIG. 5, and
contact 156 is connected through a resistor 161 to line 123 which,
as shown in FIG. 4, is connected to line 120 and hence to the
subcarrier amplifier in stage 105. Circuit 121 finally includes a
source of negative bias voltage 162, one terminal of which is
grounded and the other terminal of which is connected to the anode
of diode 163, the cathode of which is connected to the junction of
capacitor 151 and resistor 152.
Speaker selection circuit 121 operates in the following manner. The
tuned circuit comprising capacitor 135 and inductor 136 is
constructed to resonate at a frequency within the modulation of the
message signal, which according to a preferred mode of operation is
4,800 cycles. Thus, upon activation of control circuit 117 shown in
FIG. 4 in response to the presence of the particular code signal,
which causes filter 113 to be switching into the circuit to pass
the 42 kilocycle message signal to the receiver amplifier, squelch
and demodulation stage 105, the message signal is present on line
122. The signal is amplified by triode 130, rectified by diode 163,
and appears as a square wave across the divided network comprising
resistors 152 and 157. This square wave, in turn, is applied to the
input of amplifier 145. The message signal is of sufficient
amplitude so as to require only half-wave rectification as provided
by the single diode 163. An amplified signal is applied to winding
149 thereby causing movement of switching means 107 to disconnect
speakers 108 from the output of audio amplifier 106. At the same
time, energization of winding 149 causes movement of switch arm 154
to engage fixed contact 156 by virtue of the mechanical connection
160 thereby establishing a holding circuit from the output of the
amplifier in 105 through line 123, resistor 161, fixed contact 156,
resistor 157 and lead 158 to the input of triode 145. Winding 149
thus remains energized for the duration of the message signal. Upon
cessation of the message signal, contact arm 154 of switching means
153 is returned to its normal position engaging fixed contact 155
and the holding circuit is thereby opened.
FIG. 6 shows a frequency responsive control circuit 180 which is an
alternative embodiment of circuit 36 shown in FIG. 3. Circuit 180
includes a frequency responsive input portion 181 and a buffer
stage 182. Buffer stage 182 includes a major portion of circuit 36
shown in FIG. 3, and for convenience in description the identical
components are labeled with the same numbers but provided with a
prime superscript. Input stage 181 includes a semiconductor
amplifier in the form of field effect transistor 183 having gate,
source and drain terminals 184 through 186, respectively. Input
stage 181 further comprises a frequency responsive circuit 187
comprising an inductor 188 connected in parallel with the series
combination of capacitors 189 and 190. Circuit 187 is connected at
the junction of inductor 188 and capacitor 190 through a lead 191
to gate terminal 184 of transistor 183, and the junction of
inductor 188 and capacitor 189 is connected to ground.
Input stage 181 further comprises a variable capacitor 192, one
terminal of which is connected to the junction of capacitors 189
and 190 in circuit 187. The other terminal of capacitor 192 is
connected through a resistor 193 to a lead designated 37' which, as
in the embodiment of FIG. 3, is connected to line 35 and, hence,
the output of receiver limiter and discriminator stage 24. The
junction of variable capacitor 192 and resistor 193 is connected
through a feedback resistor 194 to source terminal 185 of
transistor 183. Drain terminal 186 of transistor 183 is connected
through the series combination of resistors 197 and 198 and a lead
199 to a source of B positive bias voltage. The junction of
resistors 197 and 198 is connected through a resistor 200 to
ground. A voltage output from transistor 183 is developed across a
load resistor 201, one terminal of which is connected to ground and
the other terminal of which is connected through a lead 202 to
source terminal 185. The voltage developed on resistor 201 is
applied through a lead 203 to grid terminal 47' of amplifier tube
45'. A compensating capacitor 204 is connected across cathode
resistor 52'.
Circuit 180 operates in a manner similar to that of circuit 36
shown in FIG. 3. The magnitudes of inductor 188 and capacitors 189,
190 are selected so that circuit 187 is responsive to a particular
one of the coded tone signals. The feedback in the circuit of
transistor 183 is adjusted by varying capacitor 192. This in turn
compensates for manufacturing tolerances in the components of tuned
circuit 187. Transistor 183 is a field effect transistor of the
2N3819 type characterized, in part, by having a relatively high
input impedance. This, in turn, enhances the overall
frequency-voltage sensitivity of circuit 180. The feedback in the
circuit of transistor 183 is capacitive as compared to the
inductive feedback in the circuit of tube 45 shown in FIG. 3.
When the particular coded tone signal is present on line 37',
circuit 187 resonates and acts as an extremely narrow band filter.
Transistor 183 and associated circuitry cause an appreciable
multiplication or increase in the Q of resonant circuit 187. The
resulting voltage developed across resistor 201 is applied to lead
203 to turn on tube 45'. Buffer stage 183 then operates in a manner
identical to that portion of the circuit of FIG. 3.
While several specific embodiments of the present invention have
been described in detail, this is done by way of illustration
without thought of limitation.
* * * * *