U.S. patent number 3,590,271 [Application Number 04/814,125] was granted by the patent office on 1971-06-29 for remote control system.
Invention is credited to Daniel Peters.
United States Patent |
3,590,271 |
Peters |
June 29, 1971 |
REMOTE CONTROL SYSTEM
Abstract
A remote control system employs transmitting and receiving
apparatus housed and arranged in configurations which are
particularly adaptable for use in a home, dwelling, etc., for
eliminating the necessity of extra wiring and outlet boxes. The
transmitting units are mounted in housings resembling conventional
wall switchplates normally found in the home; while the receiving
units are mounted in housings which resemble normal AC receptacle
outlets. The transmitter housings include switching means for
selectively activating the transmitter included therein, and
causing the same to propagate a predetermined frequency signal
which is responded to by a receiving unit mounted in a receiving
unit housing coacting with any one of a plurality of existing AC
wall mounted receptacles to operate any one of these existing
receptacles on a selective basis.
Inventors: |
Peters; Daniel (Springlake,
NJ) |
Family
ID: |
25214231 |
Appl.
No.: |
04/814,125 |
Filed: |
April 7, 1969 |
Current U.S.
Class: |
307/140;
340/12.32; 340/13.23; 361/182; 340/310.18 |
Current CPC
Class: |
G08C
23/02 (20130101) |
Current International
Class: |
G08C
23/02 (20060101); G08C 23/00 (20060101); H01h
047/20 () |
Field of
Search: |
;307/1120,129,140
;317/147 ;340/171 ;343/225 ;325/37 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Smith; William J.
Claims
I claim:
1. In a remote control system of the type employed in a walled
room, or a wall enclosed area, containing a plurality of wall
mounted AC receptacles distributed thereabout and energized by AC
power lines contained and routed within hollow recesses between
said walls, in combination therewith, a transmitter housing for
containing a transmitting unit adapted to transmit through space a
predetermined frequency signal when energized by a suitable power
source, comprising,
a. a housing, having front, back and side surfaces, forming a
rectangular solid having an internal hollow, and further
dimensioned so that said width and length of said front and back
surfaces are substantially larger than the thickness of said side
surfaces, said back surface of said housing further adapted for
mounting on one of said walls, said front surface having a hole
therein, contiguous with said hollow and surrounded by flanged
surfaces extending outward from said front surface, said
transmitting unit located within the hollow confines of said
housing,
b. a power source, having a first and second terminal and
positioned within said hole in said front surface and located
within said hollow, for easy removal thereof through said front
opening,
c. means, included in said hollow housing for coupling one terminal
of said power source to said transmitting unit,
d. switch contact means, having a first flexible contact coupled to
said other terminal of said power source and a second flexible
contact coupled to said transmitting unit, said switching means
located in said hollow of said housing and positioned in a fixed
position where said first and second flexible contacts are fixedly
mounted at one end and spaced apart at said other end directly
above one another,
e. a switch lever unit having front surface and side surfaces
extending in the same direction from said front surface,
surrounding the periphery thereof, and dimensioned slightly larger
than said hole in said front surface, for covering the same,
f. means mounted on said switch lever unit within the area confined
by said surfaces for coating with said flanged surfaces surrounding
said hole for securing said unit to said flange and therefore to
said front surface of said housing, said means further permitting
motion of said lever unit in directions relatively perpendicular to
said front surface, and
g. means coupled between said switch lever unit and said switch
contact means for engaging at least one of said switch contact
means at said other end, when said lever unit is moved towards said
hollow to cause said engaged contact to touch said other contact to
thereby couple said power source terminal to said transmitting unit
for energizing the same.
2. The transmitter housing according to claim 1 wherein one of said
flanged surfaces has a hole therethrough extending into and
coacting with said portion of said hollow containing said switch
contact means.
3. The transmitter housing according to claim 2 wherein said means
coupled between said switch lever unit and said switch contact
means comprises,
a. a rodlike member slideably mounted in said hole and being of a
suitable length for forcing said one of said flexible switch
contacts against said other when said switch lever unit is moved
towards said hollow to cause said rodlike member to coact with said
switch lever plate and thereby move in said same direction.
Description
This invention relates to a remote control system, in general, and
more particularly to such a system comprising remotely operated
receivers with associated transmitters, arranged in wall switch and
outlet configurations, adaptable for use in a home or dwelling and
for controlling electrical loads.
The prior art is replete with devices which are broadly classified
as remote control systems, and which function to supply electrical
power to a suitable appliance such as a television receiver, radio
and so on.
Such prior art schemes utilize a hand-held transmitter, which may
operate in the ultrasonic, radio frequency (RF) or other allocated
band. A receiver located within the appliance selectively responds
to the transmitted signal to operate a relay or other device and
thus applies electrical power thereto.
A common need in homes or dwellings is the requirement for a wall
switch to control a specific outlet. Many times a switch is
available, but it may control the wrong outlet. In other instances,
the switch is not present at all. Adding such switches can be
expensive, time consuming and difficult; and is a type of task the
average homeowner is not capable of personally implementing.
In spite of this, the concentrated efforts disclosed in the prior
art, pertaining to remote control systems, there nevertheless does
not exist an inexpensive and reliable system to meet this need
within the home or other dwelling places.
It is therefore an object of the present invention to provide a
remote control system which is simple and economical to construct
and operate.
Another object of this invention is to provide a remote control
system employing an economical transmitter unit arranged in a wall,
switchlike housing normally found in the home.
A further object is to provide economical remote control systems
employing receivers and transmitters arranged in suitable
enclosures adaptable for coacting with or plugging into
conventional electrical outlet configurations.
In accordance with a feature of this invention, a transmitter and
receiving apparatus are provided for use in a remote controlled
system, particularly suited for operation within a wall enclosed
area or room; the transmitter unit are located within first hollow
housings, having switch means mounted thereon for coupling a source
of power to a transmitting unit included in said housing, for
energizing the same. The transmitter housing, as fabricated, may be
of the approximate dimensions, but slightly thicker, than a
conventional wall switchplate normally found in a room or home.
Upon energization of the transmitting unit a frequency signal is
caused to propagate and is selectively captured by a receiver unit
mounted within a second hollow housing and having a male receptacle
mounted on a back surface thereof, which receptacle coacts with any
one of a plurality of AC receptacles normally found within said
walled enclosed area. The receiving unit activates a relay circuit
which couples AC power from said male receptacle to an AC
receptacle mounted on the front surface of the housing.
In this manner the transmitter wall housing, having a back surface
adapted for mounting said housing on one of said walls at any
predesired location, can selectively energize one receiver unit
contained in said second housing, which is plugged into any one of
a plurality of existing AC wall receptacles by means of said back
surface mounted male receptacle.
Other embodiments and features show unique and novel receiver
configurations employing a plurality of threshold circuits to offer
improved noise immunity for such remote control systems as will be
further explained and described.
The novel features which are considered to be characteristic of
this invention are set forth with particularity in the appended
claims. The invention itself, however, both as to its utilization,
organization and method of operation as well as to further objects
and advantages thereof, will best be understood from the following
description when read in connection with the accompanying drawings
in which identical numerals reference similar components and in
which:
FIG. 1 is a plan view of a portion of a typical room employing
electrical outlets and wall switches useful in explaining the
invention;
FIG. 2 is a front plan view (FIG. 2A), a side plan view (FIG. 2B),
and a back plan view (FIG. 2C) of a remote control transmitter wall
switch housing assembly according to this invention;
FIG. 3 is a perspective plan view of a switch lever plate as shown
in FIG. 2B;
FIG. 4 is a sectional side plan view used in explaining the
switching mechanism as utilized in the transmitter assembly of FIG.
2A, taken about line 4-4;
FIGS. 5 and 6 are schematic diagrams of transmitter units as may be
contained in the housings of FIG. 2;
FIG. 7 shows another embodiment of a schematic representation of a
transmitting unit;
FIG. 8 shows a front plan view (8A) and a side plan view (8B) of a
receiver unit housing according to this invention;
FIG. 9 is a schematic diagram in block form of a receiving
unit;
FIG. 10 is an electrical schematic diagram of an ultrasonic
receiver unit for use with the invention;
FIGS. 11 and 11A are electrical schematic diagrams of transmitting
units for use with this invention;
FIG. 12 is a circuit diagram of an alternate embodiment of a
receiving unit; and
FIG. 13 is a circuit diagram of a receiving unit according to the
invention .
Referring to FIG. 1 there is shown a plan view of two walls 10 and
11, in part sectional view, and a doorway 12.
In most homes, office buildings and so on, a similar room, office
or other arrangement exists together with AC wall receptacles as 15
and 16, for accommodating various appliances, lighting fixtures and
other devices, which require electrical power in order to properly
operate. Shown in FIG. 1 is a lamp 17, having an on-off switch 18
with a line cord 19 terminated at one end with a male plug
receptacle 20, for insertion into an AC wall receptacle as 15 or
16. The AC receptacles 15 and 16 are energized by coupling suitable
terminals of the receptacles to AC power lines 21 and 22,
originating from a common source, in the home as a control fuse box
and so one. The AC lines 21 and 22 are routed and fixed in place
during the construction of the home or building prior to the
construction of the walls 10 and 11 of the room and the floor.
The walls and floors are then constructed so that the power lines
21 and 22 are enclosed within the hollows between walls 10 and 11
or beneath the floor and are not easily accessible without breaking
into or in some other costly manner damaging both the walls and
floor.
During the routing of the AC power lines 21 and 22 a wall switch 25
may also have been provided by the electrician or builder and
coupled to the power lines, so that one of the receptacles 15 or 16
can be selectively energized by the operation of the switch 25. In
this manner there is shown the power lines 21 and 22 coupled
directly to the proper terminals of the AC receptacle 15. The power
line 21 is also coupled to a proper terminal of the AC receptacle
16 while the power line 22 is coupled to the other terminal of
receptacle 16 through the wall switch 25.
Alternatively, the home so prewired may not include a wall switch
25, and therefore both AC receptacles 15 and 16 are prewired to the
power lines 21 and 22 directly. This configuration is alluded to in
the drawing by showing the wire 22', which would correspond to line
22 in the absence of the wall switch 25.
With the arrangements shown in FIG. 1, the wall switch 25 when
operated will energize the "light bulb" of lamp 17 if the on-off
switch 18 is in proper position. Hence as an individual enters the
room, via doorway 12, he may operate the lamp 17 via the wall
switch 25. It is also clear, that if the room were not so provided
with the wall switch 25, operation of the lamp 17 would be strictly
under the control of the on-off switch 18.
At least two problems can be seen arising from the above
arrangements.
Firstly, assume that one desires to locate the lamp 17 at a
location near receptacle 15; and hence inserts the line cord 19 of
the lamp 17 (via the male plug 20) into receptacle 15. This action
therefore removes the desired control of the lamp 17 from the wall
switch 25. To solve this problem, one would have to run an
extension line from receptacle 16, which is wall switch controlled,
to a new AC receptacle which may be mounted on the wall or
otherwise near the new position of the lamp 17.
In order to prevent accidents, and to further mask the extension
wire from view, the extension wire routing path may be under a rug
or behind a molding, or otherwise tortuous in nature, requiring
extra length of wire and a great deal of time to so implement. If
one desires to insert the wire through the walls, by a so called
"snaking" technique this may require considerable time or actually
be impossible to implement, due to obstruction of beams, insulation
and so on included within the hollows between walls or beneath the
floor (i.e. second story homes, etc.). In any event if the
homeowner or other person is not familiar with electrical
connections, as is the common case, he would employ the services of
an experienced electrician at a relatively large expense.
Oftentimes, a wall switch 25 does not exist, at all, and if one
desires to so control a lamp or other device a switch as 25 has to
be added.
This, of course, is still a greater problem as the wiring, the
routing, together with the masking of the new wire paths; plus the
inclusion of the switch receptacle and box, is an expensive, time
consuming, and difficult task. In general, such an electrical job
is most likely beyond the capabilities of the average homeowner, so
that he is forced to hire an electrician.
Referring to FIG. 2 there is shown front (2A), side (2B) and back
(2C) plan views of a remote control transmitter housing 30
according to the invention.
The housing 30 is fabricated, by molding or otherwise from a
suitable plastic material and may be of a rectangular or other
symmetrical pleasing configuration having a length and width
greater than the thickness of the sides. The housing 30 has the
appearance of, and is preferably dimensioned, as a conventional
switch wallplate unit, normally found in the home, but may be
slightly thicker as will be explained subsequently.
The back surface 31 of the housing 30 as seen in FIG. 2B may be
stippled, scored or otherwise roughed or treated, adapting it for
cementing to a wall (as 11 of FIG. 1) at a desired location,
determined by the user. Alternatively, the back surface 31 may be
treated with a suitable glue and covered by a waxed paper layer.
When a location is selected the paper is removed and the unit 30
pressed into place.
The housing 30 has a battery accommodating hollow or recess 32 on
the front surface 33. A battery 34 is located within hollow 32 for
easy removal from the front of the housing when replacement is
required. The battery 34 is coupled to a transmitter assembly 35 by
means of a conventional plug assembly 37 having a positive and
negative terminal and associated wires. The battery 34, may be that
as found in most portable radios and so on. The battery 34, as
shown therefore may be a conventional 9 volt NEDA-1604 type,
commonly employed in transistor radios, etc. A hole in the front
surface of the housing 30 accommodates a mesh plug unit 36, which
is force fitted or otherwise secured therein, to permit easy
propagation of the RF or ultrasonic oscillations afforded by a
transducer mounted on the transmitter assembly 35, through the
holes in the mesh unit 36.
Surrounding the battery accommodating recess 32 is a flange 38,
molded as part of the housing 30. The flange 38 has a lip or bottom
curved channel 40 and a top lip 40' for accommodating wire spring
members 44 and 44' associated with a switch lever plate 42.
Referring to FIG. 3 the switch lever plate 42 is shown more
clearly. The plate 42 may be fabricated from plastic or a suitable
metal and is dimensioned to be larger then the flange 38
surrounding the battery hollow 32. A wire member 44 is located near
the bottom end of the lever plate 42 and a wire member 44' is
located near the top end of the lever plate 42.
A rubber or resilient member 43 is located nearer the top end of
the lever 42 and is cemented or otherwise fastened to the inner
surface of the switch lever plate 42.
Referring to FIG. 2B, a side view of the switch lever plate 42 is
shown physically coupled to the side view embodiment of the
switchplate housing 30. With the battery 34 positioned as shown,
one merely pushes or forces the switch lever plate 42 about the
flange surface of the housing 30 directly above the battery recess
32. The springlike wire members 44 and 44' (as shown) are forced
onto the lips 40 and 40' within the accommodating channels, thereby
securing the lever plate 42 to the housing 30.
The flange 38 has a hole 45 therein, which coacts with a hollow,
contiguous with the battery hollow 32, containing a switch
arrangement.
The switch comprises two flexible, conductive contacts 46 and 47,
as relay contacts and so on, fabricated from a suitable conductive
metallic material. The flexible contacts 46 and 47 are secured to
the housing, at one end thereof, by means of screws, or otherwise,
and are preassembled through a suitable access area which may be
provided for on the back or front surfaces of the housing. The
contacts 46 and 47 as secured do not touch each other or otherwise
make contact. A proper wire from the battery 34 is prewired to one
contact as 46 while a wire from the transmitter assembly 35 is
wired or soldered to the other contact 47. A small rod 48 is
inserted through the hole 45, as more clearly shown in FIG. 4. The
rod or other suitable member 48, extends beyond the flange 38 of
the housing 30 and is slideably mounted within the hole 45. With
the lever plate 42, positioned with the wire spring members 44 and
44' coacting the lips of the flange 38, as described above, the
rubber or resilient member 43 rests on the battery surface and the
rod 48 touches the back surface 50 of the switch lever plate 42. If
a force is exerted on the front surface of the lever plate 42 the
resilient member 43 compresses, the lever plate 42 moves, forcing
the rod 48 to engage the flexible contact 46 thus moving the same
to contact member 47. In this position the wire labeled from
battery is connected through the contacts 46 and 47 to the
transmitter assembly 35.
The housing 30 as fabricated may have an exposed back surface 31
which is finally covered by a treated cover plate, as described
above, which may be permanently secured or fastened thereto by
suitable means.
FIG. 2C shows a back view of the housing 30 showing the contacts 46
and 47, the battery 34 and the transmitter assembly 35.
Briefly, when the switch lever plate 42 is pushed the rod 48 closes
the contacts 46 and 47 and power from the battery 34 is coupled to
the transmitter assembly 35, which oscillates at a predetermined
frequency and causes such oscillations to propagate through space
by means of a suitable transducing unit (as an antenna and so on)
included on the transmitter assembly 35.
Referring to FIG. 5 there is shown a schematic, using electrical
symbolization, to further explain the operation of the contents of
the assemblies shown in FIGS. 2, 3 and 4.
The battery 60 may be a 9 volt, transistor radio, type which is
preferably longer and wider then it is thick. The battery thickness
is determinative of the thickness of the assembly of FiG. 2, as can
be seen. The battery 60 has one terminal (-) permanently connected
to the oscillator 61 and a second terminal coupled thereto via the
switchable contact 63. The output terminals of the oscillator 61,
are coupled to suitable transducer 64. Transducer 64 is shown
schematically as an ultrasonic transducer, which are known in the
art. Accordingly, the oscillator 60 provides a frequency signal in
the ultrasonic range (i.e. 35 to 40 kHz.) which is caused to
propagate through space due to the transducer 64 action.
FIG. 6 shows a similar schematic to that of FIG. 5, showing the
battery 60, switch 63 and an oscillator 65 with a loop-stick
antenna 66 adapted to operate in the 160--190 kHz. band, which band
is presently allocated for remote control systems. Many examples of
suitable transmitting arrangements can be accommodated within the
housing or assembly 30 shown in FIG. 2 and, as such, are known in
the prior art.
A particularly useful and economical configuration will be shown
and described subsequently, in greater detail. It is also known
that one can utilize a tuning fork or other mechanical type
oscillator assembly and suitable transducing equipment, mounted
within the housing 30 as shown in FIG. 2, and thereby eliminate the
requirement for the battery 60. However, many such units are too
bulky and expensive for conveniently so incorporating.
FIG. 7 shows a transmitting unit schematic containing an oscillator
67 and suitable transducer 68 for plugging into a wall receptacle
by means of the male connector 70. The coacted AC wall receptacle
also furnishes operating power thereto, by energizing a power
supply 69, as will be further described and explained
subsequently.
Referring to FIG. 8A there is shown a front view of a receiving
unit 80 according to this invention. The unit 80 has one or more
conventional AC receptacles 81 and 82 mounted on the front surface
thereof.
FIG. 8B shows a side view of the receiving unit 80. The unit 80 has
mounted on a back plate or surface, a male plug adapter 83 for
insertion into a conventional AC wall receptacle. A receiving
transducer unit 84 is coupled to a selective filter 85 which is
followed by a high gain or selective amplifier 86. The electronic
assembly, as shown, generally by the above noted components, is
located and mounted within the receiver assembly housing 80.
A wire 87 couples one terminal of the AC male plug adapter 83 to a
terminal of the female AC receptacles 81 and 82 and is used as a
common lead or reference potential bus for the receiver unit. The
other terminal of the male plug 83 is coupled to the input of a
power supply module 88 to energize the amplifier 86 and other
receiver circuitry, as will be further described. This terminal of
the male plug 83 is also coupled to a module 89 containing a
suitable power switch as a relay circuit and contacts, or an S.C.R.
circuit equivalent in operation to a relay and used for selective
coupling of a AC power to receptacles 81 and 82.
The module 83 is coupled to the output of the high gain amplifier
86 and is energized when the receiving unit 80 receives a suitable
transmitted oscillatory signal within the frequency band-pass of
the filter 85 included therein. Such a signal is generated by a
transmitting wallplate unit as described in FIGS. 2, 5, 6 and 7. In
this manner operation of the power switch module 89 completes the
connection from the male plug 83 to the front mounted receptacles
81 and 82 mounted on the receiving unit 80.
As seen from the front view, or FIG. 8A, the receiving unit 80
appears as a conventional AC receptacle as normally found in a home
and so on.
The electrical components forming the transmitter shown in FIG. 7,
are also easily accommodated in a housing 80 as shown in FIGS. 8A
and 8B. If so mounted, an existing wall switch (as 25 of FIG. 1)
positioned on a wall in a room may control any desired wall mounted
AC receptacle (as 15 of FIG. 1). Accordingly, one would insert a
transmitter unit as shown in FIG. 7, contained within a housing 80
(as 80 shown in FIGS. 8A and 8B), into the prewired AC receptacles
(as 16 of FIG. 1). The switch 25 would still selectively energize
one of the receptacles 81' or 82' corresponding to 81 and 82 of
FIGS. 8A and 8B, as seen from FIG. 7. However, the activation of
the switch would also couple AC power from the receptacle (16 of
FIG. 1) to the power supply unit 69 (FIG. 7); and thusly, energize
the oscillator 67 to cause a signal to propagate via transducer 68.
A receiving unit plugged into receptacle 15, would respond to the
transmitted signal and energize the receptacles 81 and 82 of FIGS.
8A and 8B.
Thus, if a homeowner or other person, inserted a transmitter unit
(FIG. 7) housed within a housing (80 of FIGS. 8A and 8B) into
receptacle 16 and inserted a receiver unit (80 of FIGS. 8A and 8B)
into receptacle 15, the existing wall switch (25 of FIG. 1) would
serve to activate any appliance (as lamp 17 of FIG. 1) inserted in
the receiver AC receptacle as 81 or 82 when activated. This action
eliminates the need for the user to utilize extension cords, run
new wires, provide new receptacles or boxes, and so on.
FIG. 9 shows a schematic diagram in block form of the electrical
circuit included in a receiving housing 80 as shown in FIG. 8 and
adaptable for responding to and receiving RF signal transmissions
for an RF wall switch mounted transmitter, as shown in the
electrical schematic of FIG. 6. The modules and related functions,
shown in FIG. 9 are well known in the prior art, as is this
particular schematic for a remote control receiver.
FIG. 10 shows an electrical schematic of ultrasonic receiver
circuitry whose physical counterparts can be accommodated within a
housing 80 as shown in FIG. 8.
The receiver employs an ultrasonic receiving transducer 90, which
may be a frequency selective microphone. Hence the transducer 90
performs selective filtering, as well as being sensitive to
propagated ultrasonic (35 to 40 kHz. signals. The transducer 90 is
followed by a high gain amplifier 91 which amplifies the low level
received signal and applies the same to a rectifier circuit 92,
including a proper filter at an output, for providing a DC voltage
proportional to the amplified frequency signals received. The
rectifier circuit 42 may comprise a full or half wave rectifier in
a bridge or other well known configuration together with an output
R-C, R-L, or RLC network having a time constant suitable for
providing a low ripple DC voltage. The rectified DC is applied to a
DC threshold amplifier 93 for actuating a bistable multivibrator 94
or flip-flop (F/F) circuit.
The flip-flop circuit 94 has two stable states. One state serves to
energize the power switch module 95, which may be a silicon
controlled rectifier (SCR) circuit or an electromechanical relay.
Energization of the power switch 45 connects the wire 98 to the
wire coupled to receptacle 96 via the low impedance path of the
power switch 95.
Power for the receiver is provided for by a power supply (P.S.)
circuit 99 which is energized by the AC power applied to the male
connector 97, when plugged into a conventional AC wall
receptacle.
Generally, the receiver of FIG. 10 operates as follows:
Assume, the F/F 94 is initially in one stable state, corresponding
to the inactivation of the power switch 96. The male plug 97 is
inserted into an AC wall receptacle and the power supply 99
energizes the modules as shown. A ultrasonic wall switch
transmitter, in a housing (as 30 shown in FIG. 2) is energized and
propagates the ultrasonic signal. The transducer 90 responds to and
applies the received signal to the amplifier 91, the amplified
signal is rectified and filtered, and a DC threshold voltage
triggers the flip-flop 94 to change the state. The change of state
energizes the power switch 95, thereby coupling full AC power as
applied to male plug 97, from an AC wall receptacle to the female
outlet 96 (as 81 of FIG. 8) mounted on a receiver housing (80 of
FIG. 8).
Referring to FIG. 11 there is shown an electrical schematic of a
suitable transmitter unit for inclusion in a housing as shown in
FIG. 2.
A transistor 100 is used in an oscillator configuration, having a
base electrode coupled to a terminal of a suitable frequency
selective feedback network 101, containing inductors and
capacitors. Suitable oscillator arrangements are well known for use
in the ultrasonic band as Colpitts, Hartley and so on. See for
example a text entitled "Functional Circuits and Oscillators" by
Herbert J. Reich, D. Van Nostrand, Inc. 1961, Page 349 for suitable
configurations.
The switch 102 corresponds to the switch mechanism mounted on the
front of the transmitter switch, wallplate, like housing (FIG. 2)
and serves to couple the battery 104 thereto via a collector load
impedance, to energize the transistor oscillator and thus cause
oscillations. The feedback network 101 is fabricated as a
transponder or transducer as well, and permits propagation of the
frequency signal through space. Such units are well known in the
art and for example have been used in remote control television
systems.
The circuit shown in FIG. 11 need only employ a single transistor
100 and two resistors 105 and 106 used for biasing and base current
limiting respectively. The components are physically small and not
critical as to selection and are therefore easily accommodated in a
suitable transmitter housing (30 of FIG. 2).
FIG. 11A shows a power supply unit for use with a transmitter
mounted in a housing as shown in FIG. 8. The male plug 109 (of FIG.
8) supplies AC power to the half wave rectifier unit including
diode 108, and capacitor 110. A resistor 107 furnishes a voltage
drop to bias the zener diode 122 which has a rating equal to the
battery rating used in FIG. 11.
FIG. 12 shows a schematic of a receiving circuit for ultrasonic
transmissions. An ultrasonic selective microphone 111 is coupled to
the input of an operational amplifier 112 which is preferably a
high gain type and of an integrated circuit construction. An
example, of a suitable type is the CA3035 manufactured by R.C.A.,
Electronic Components and Devices, Harrison, New Jersey. See a
publication entitled "CA3035 Ultra High-Gain Wide-Band Amplifier
Array," File No. 274, 6--67, wherein a typical remote control unit
and suitable component values are shown, similar to that of FIG.
12.
Briefly, FIG. 12 further shows a male receptacle 115 which when
inserted into a suitable AC wall receptacle will energize the power
supply comprising the current limiting resistor 117, the rectifier
118 and the filter capacitor 119 and therefore supply operating
potential to amplifier 112.
A portion of the integrated circuit amplifier 112 is used as a
rectifying element. If reference to the above noted publication
(CA3035) it can be seen that such amplifiers comprise a plurality
of monolithic integrated circuit amplifier configurations on a
common substrate. By operating certain stages, thereof, without
applying biasing potential, one can use the monolithic transistors
in nonlinear rectifying circuits and therefore the output of the
amplifier 112 is a rectified AC signal which when applied to
capacitor 124 develops a DC potential thereacross proportional to
the amplitude of the transmitted signal. When the DC voltage across
the capacitor 124 is approximately equal to the DC across the zener
diode 123, the relay coil 122 is not energized, and power is
applied to the AC receptacle 116 via contact 113. As soon as a
transmission ceases the voltage across capacitor 124 decreases and
the relay is energized. Relay 122 is an impulse type and may
include a mechanical locking mechanism, holding coil or contact,
which retains the relay contact 113 in the activated position until
another transmission occurs thus opening contact 113. Such impulse
or sequencing relays 122 are known in the prior art.
Accordingly, as one enters a room or area and depresses the switch
lever plate of the transmitter wall unit (30 of FIG. 2) the signal
transmission activates the receiver relay 122 which applies AC line
potential via contact 113 to receptacle 116.
The impulse relay 122 locks in this position. As one leaves the
room the transmitter switch lever plate is again depressed,
releasing the relay contact 113 and locking it in the open
position.
Referring to FIG. 13, there is shown a receiver unit capable of
responding to ultrasonic frequency transmissions, which employs
inexpensive transistor components, and further eliminates the
necessity of using an impulse type relay as previously described in
conjunction with FIG. 12.
An ultrasonic transducer or selective microphone 130 is coupled to
the input electrode of a high gain amplifier 131 preferably of an
integrated circuit configuration and as indicated above
commercially available. The output terminal 132 of the amplifier is
coupled to a filtering capacitor 133 connected between the output
terminal and a source of reference potential. A load resistor 134
couples the output terminal of the amplifier to a source of
potential through a dropping resistor 135.
The source of potential comprises resistor 136, rectifier 137 and
filter capacitor 138 and is energized by inserting the male
receptacle 139 in an appropriate wall mounted AC power receptacle.
A stabilized operating voltage for the amplifier 131 is obtained
from zener diode 140 coupled between the junction of resistors 134
and 135 and ground. The output terminal 132 of the high gain
amplifier 131 is coupled to the cathode electrode of a zener diode
141; having an anode electrode directly coupled to the base
electrode of a transistor 142. Transistor 142 has the emitter
electrode coupled to ground and the collector electrode coupled to
a source of potential through a load resistor 144.
The collector of the DC amplifier transistor 142 is coupled to one
terminal of a filter capacitor 145 having the other terminal
coupled to ground. A neon bulb 150 has one terminal coupled to the
collector electrode of transistor 142 and another terminal coupled
to ground through a resistor 151. The neon bulb, as will be
described, is used for generating triggering pulses for a bistable
multivibrator or flip-flop circuit comprising transistors 152 and
153.
The flip-flop arrangement is triggered by a pulse coupled across
capacitor 156 which is connected between resistor 151 and the base
electrodes of transistors 152 and 153. The base electrodes of
transistors 152 and 153 are coupled to the other terminal of the
capacitor via resistors 157 and 158. A common emitter electrode
return path for both transistors is provided by resistor 159
coupled between the respective emitter electrodes and a point of
reference potential, such as ground.
The base resistors 157 and 158, as coupled to the terminal of
capacitor 156, are shunted to ground through a resistor 160.
Suitable regeneration is provided for the flip-flop circuit, by
resistors 161 and 152, coupled respectively from the collector
electrodes of transistors 152 and 153 to the opposite base
electrodes thereof.
A collector load is provided for transistor 153 by resistor 164
coupled between the collector electrode and the source of operating
potential. The collector electrode of transistor 152 is coupled
through a resistor 165 and a relay coil 166 in series to the source
of operating potential. The relay coil 166 has associated therewith
a contact 167 having one terminal thereof coupled to one side of
the female receptacle 170, having its other terminal coupled to the
ground side of the line. The operation of the circuit thus
described is as follows.
For the absence of an ultrasonic transmission or ultrasonic
frequency propagation the voltage at output terminal 132 of the
amplifier 131 is positive. The zener diode 141 is conducting and
serves to forward bias transistor 142, thereby producing a low
collector voltage. There is little charge developed across
capacitor 145 during this mode and the transistor multivibrator is
in the state corresponding to current flowing through resistor
164.
Accordingly, there is little current flowing through the relay coil
166 and hence contact 167 is open and no AC line power is coupled
to terminal 170. If one activated a suitable ultrasonic wall
mounted transmitting unit to cause an ultrasonic frequency
propagation the following operations would occur.
The selective transducer 130 responds to the propagated signal and
applies the same to the amplifier 131. The amplifier 131 provides
an AC rectified type signal which is filtered by capacitor 133
until the voltage across the capacitor is no longer sufficient to
maintain the zener diode 141 in conduction. This reverse biases
transistor 142 and permits the collector electrode to go towards
the supply potential. Capacitor 145 charges through resistor 144
towards the supply potential until the voltage thereacross is
sufficient to break down the neon 150.
The capacitor 145 discharges through the neon 150 and resistor 151
to provide a positive pulse coupled through capacitor 156, which
pulse couples to the base electrode of transistor 152; thus turning
on transistor 152. The collector voltage of transistor 152 drops to
a low value and by regeneration turns off transistor 153. The
collector current flowing through transistor 152 is sufficient to
operate the relay contact 167 via the coil 166. AC power is now
available at receptacle 170. The flip-flop maintains this state
until another transmission occurs wherein the same sequence of
events takes place, thus transferring the flip-flop back to its
initial state and thereby serving to remove power from receptacle
170 by opening contact 167.
The circuit shown in FIG. 13 provides extreme immunity against
spurious noise pulses from operating the multivibrator. The
ultrasonic frequency band (35 to 40 kHz. is subjected to
interference from many sources of noise, produced by common, every
day sounds. For example the sounds accompanying running water (from
faucets, showers), the clattering of metal, tolling bells, etc.,
all have components in the ultrasonic band.
In the circuit shown such spurious frequencies because of their
statistical and random nature will not easily trigger the
multivibrator described herein. Noise immunity is provided by
capacitor 133 which must charge to a sufficient level to reverse
bias the zener diode 141. The threshold voltage of the zener diode
141 must be overcome before transistor 142 can be turned on. The
incoming signal must persist until capacitor 145 charges through
resistor 144 to a suitable level sufficient to trigger the neon
150. If all of these conditions and times are met the flip-flop
will exhibit a transition. Due to the nature of noise and the power
and duration of such noise pulses, it has been found that such
sources are not sufficient to falsely operate a circuit as shown in
FIG. 13 which utilized the following components. ##SPC1##
The above components were mounted on a conventional phenolic board
approximately 2.times.3inches and contained within a housing
configuration as shown in FIG. 8, which resembles a conventional AC
wall receptacle. The receiver was selectively energized by a
transmitter unit, having the circuit configuration shown in FIG. 11
and contained within the housing of FIG. 2 which was fastened to a
wall at a desired location by cementing the back surface thereof to
said wall. The system thus described reliably turned on a 200 watt
bulb from distances of 20 or more feet.
* * * * *