US 3360777 A
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Dec. 26, 1967 PULSE REG Filed July 16, 1964 EIVER RESPONSIVE TO PLUR HAVING FREDETERMINED TIME SEPARATIO E. A. KOLM ATTOR N EYS' United States Patent Office 3,360,777 Patented Dec. 26, 1967 PULSE RECEIVER RESPONSIVE T PLURAL CODE GROUPS HAVING PREDETERMINED TIME SEPARATION Eric A. Kolm, Brookline, Mass., assignor to Kolm Industries, Cambridge, Mass. Filed July 16, 1964, Ser. No. 383,181 4 Claims. (Cl. 340-164) This invention relates to a sonic switch. More specifically, it relates to a switch which may be closed or opened in response to a predetermined sequence of audible signals. The invention is particularly directed to remote operation of electrical devices, such as household appliances, controllable by means of switches or like components.
Remote control systems for such devices may be generally classified into two types, namely wired and wireless systems. The wired systems have the obvious disadvantage of relative inflexibility with regard to change of position of either the controlled device or the source of the control signals. Also, most wired systems are impractical for use over long distances. On the other hand, wireless systems, which use radio or acoustic control signals, are much more flexible with regard to location of the components. However, control from long distances by means of a radio system is impractical in most cases; and it is impossible if a strictly acoustical system is contemplated.
An object of the present invention is to provide a system for remote control of electrically operable devices.
Another object of the inventionis to provide a remote control system which is practical for use with household appliances.
Another object is to provide a system of the above type which is operable from various locations far removed from the controlled devices.
A further object of the invention is to provide a sys tem of the above type which is highly flexible in that it does not require the user to transport equipment from one control location to another.
Yet another object of the invention is to provide a remote control system of the above type which is relatively unaffected by spurious signals in the frequency range of the control signals.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a remote control system incorporating the invention; and
FIG. 2 is a schematic diagram of a second embodiment of the invention.
In general, the present invention employs a sonic system in which a timed sequence of sounds or soundiike signals actuate a switch to turn on or off the controlled successively actuated by a series of input signals, the next signal actuates a final stage which connects a power source to the controlled appliance. This final stage is preferably an impulse type relay having two positions, i.e., an on position and off position. Thus, the first signal reaching this relay turns the appliance on; later the appliance may be turned off by means of another succession of signals, the last one of which actuates the impulse relay.
In order to lessen the danger of operation of the system by spurious signals, each of the relays in the cascaded chain is held, after actuation, by a holding circuit includ ing a time delay element. After a short period of time this delay element releases the relay. Thus, if a further signal is not received within a short period of time after the actuation of a relay in the chain, the consequent release of the relay will open the connection between the signal source and the next relay in the chain, thereby preventing actuation of the latter relay by the next signal. In effect, this resets the entire system and the sequence of signals must be begun again in order to carry a signal through to the end of the relay chain.
The remote control system may be arranged to accept sound signals associated with the human voice. Thus, spoken commands may be used. For example, one using the system may audibly count at a given rate until the number corresponding with the required number of signals is reached.
For operation from a distant location the remote control system may incorporate the telephone network, generally in either one or two modes. In one such mode, the user employs a telephone answering device which may take the form of any of a number of suitable automatic telephone answering devices presently available. The answering device responds to a telephone call by coupling the telephone line to a signal pickup element associated with the relay chain. At the other end of the telephone line, i.e., remote from the users home substation, the user then utters the required operating signals, to which the relay chain responds in the manner described above.
In another arrangement associated with the telephone network, the relay chain is arranged to respond to the ringing signals. The user dials his home number and a predetermined number of rings accepted by the relay chain results in operation of the controlled device. In order to prevent operation by spurious signals, caused by others who might dial the users telephone number, a lockout arrangement may be employed which requires the user to dial his number, wait a predetermined number of rings and then hang up and dial again, in orderfor the ringing signals to be processed through to the end of the relay chain.
FIG. 1 illustrates the operation of the invention in controlling an appliance 10 in the users home from a remote telephone station 12. The user dials his home telephone number and the telephoneexchange connects the remote station 12 to the telephone station 14 in his home. In the illustrated arrangement the station 14 includes, in addition to a conventional telephone instrument, an automatic telephone answering device. The answering device, either by means of a direct connection to the telephone line or by removing the telephone hand set from its cradle, responds to an incoming ringing signal by connecting the telephone line to apparatus able to hold the line and receive subsequent messages or signals transmitted thereover. These signals or messages in turn are passed to an electro-acoustical transducer 16.
The transducer 16 may, illustratively, be the receiver incorporated in the telephone handset, in which case the answering device is of the type which removes the hand set from its cradle in response to an incoming signal.
The transducer 16 emits acoustical signals which are picked up by a second transducer 18 in close proximity thereto and reconverted into electrical signals. These signals are processed by a relay chain, generally indicated at 20, which operates in the manner similar to that of a counter. Thus, when a predetermined number of such signals have been processed by the chain 20, an output signal therefrom is applied to an impulse switch 22 which connects the appliance to a power source 24-, or alternatively disconnects it therefrom.
More specifically, the signals from the transducer 18 are amplified by an amplifier 26 whose output is rectified by a rectifier-filter 28. The amplifier 26 preferably has a pass band limited to the fundamental frequencies ordinarily produced by the human voice, so as to limit the spurious signal energy passed to the rectifier-filter. Als it preferably has a high gain together with amplitude clipping, thereby providing an output whose amplitude is fairly independent of the amplitude of the input signals from the transducer 18.
The rectifier-filter 28 converts the output of the amplifier 26 to a direct-current signal and applies an averaging or smoothing action to this signal. This lessens the probability of noise within the pass band of the amplifier 26 having an appreciable effect on the output of the rectifier-filter.
Next, the signal is passed through a differentiator 30, which provides an output in response to changes in the output level from the rectifier-filter 28. This prevents sustained sounds from being acted upon by the system. That is, the diiferentiator 30 emits an output signal only when there is a change in the level applied to the transducer 18. With high gain and clipping in the amplifier 26 as described above, this means that there must be virtually a complete cessation and then a re-introduction of the audi level at the transducer 18 for the differentiator 30 to provide an output. Preferably, the differentiator includes a diode arrangement in its output which permits output signals of only one polarity to be passed to the relay chain 20. Thus, there is a single output pulse from the differentiator 30 for every burst of audio signal passing from the transducer 16 to the transducer 18.
The relay chain includes a plurality of relay stages 32, 34 36 employing relays 38, 40 42. The stage 32, which is the first stage in the chain, receives the first of a series of input signals from the differentiator and succeeding signals are applied in order to the successive stages, until the final stage 36 has been actuated. The next following signal actuates the impulse switch 22 to turn on or off the appliance 10.
That is, the first of a series of operating signals from the ditierentiator 30 is applied to the coil 38a of the relay 38-by way of the series combination of normally closed contacts 40d and 42d of the relays 40 and 42 and an isolating resistor 44. This pulse brings about closure of a holding contact 38b and a carry contact 38c. The contact 38b is in a holding circuit comprising, in series, a battery 46, a normally closed delay switch 48 and the coil 38a. The battery 46 is merely illustrative of various power supplies which may be used. The switch 48 may be of a conventional time delay switch which opens after current has passed through it a predetermined length of time. Illustratively, it may include a bimetallic movable arm which is heated by a heating element through which the current passes. After the relay holding current has flowed for the desired interval, the temperature of the arm reaches a point at which the arm moves away from a fixed contact within the switch, thereby opening the switch 48 and releasing the relay 38. This opens the contacts 38b and 380. It will be understood that other types of delays can be used in the system, e.g., capacitance-resistance holding circuits.
If a second pulse from the diiferentiator 30 is received during the interval in which the carry contact 38c is closed, this pulse will be passed to the coil 40a of the relay 40 by way of an isolating resistor 50. Again, actuation of the relay in this manner causes closure of a holdcarry contact 400 and the relay 40 delay switch 52 connected to the iug contact 40b and a is held by means of a battery 46.
Thus, the next output pulse from the differentiator 30 passes through the contact 400 to the coil of the next relay in the relay chain. Assuming, for the purpose of illustration, that the next relay is the relay 42 in the final stage 36, this pulse energizes the coil 42a by Way of an isolating resistor 54. Contacts 42b and 42c then close and holding current from the battery 46 passes through the contact 42b by way of a delay switch 56.
The next pulse from the ditferentiator 30 passes through the contact 42c to actuate the impulse switch 22. As an example, the switch 22 may be a conventional twoposition rotary impulse switch which shifts from one position to the other each time it receives a pulse from the contact 42c. In one position it connects the power source 24 to the appliance 10 and in the other position the appliance is disconnected from the source 24.
Thus, a series of successive pulses from the diiferentiator 30, corresponding to a series of audio signals transmitted from the remote telephone station 12, causes successive actuation of the relays in the relay chain 20, with the final pulse actuating the appliance 10. The number of pulses required depends on the number of stages in the relay chain. With the three illustrated stages connected as shown, four pulses are required, one to actuate each of the relays, and one for the impulse switch 22. If additional stages are inserted, as indicated by the dotted lines between the stages 34 and 36, an additional pulse will be required for each stage. Alternatively, the contact 420 might connect the impulse switch 22 to the battery 46, with the resulting current step through the switch 22 actuating it. In that case, the number of pulses from the diflerentiator 30 required for actuation of the switch 22 will be equal to the number of stages in the relay chain.
The delay switches 48, 42 and 56 operate to reduce the chance of actuation of the switch 22 by spurious signals. Specifically, Whenever a relay has been actuated by a pulse from the differentiator 30, the next pulse from the dilferentiator will not be passed to the succeeding stage of the relay chain unless the carry contact of the relay is still closed when the latter pulse arrives. The coil of the actuated relay is de-energized by operation of the associated delay switch within a short period, e.g., ten seconds, after actuation. Thus, for a pulse to be passed by a relay to the next stage in the chain, it must arrive within this short interval following the previous pulse which actuated the relay. Thus, after a relay has been opened by operation of its delay switch without having passed a pulse to the next relay in the chain, the chain is broken. The system is thus reset so that the next pulse from the differentiator 30 will be applied to the first relay in the chain, i.e., the relay 38.
For proper operation of the relay chain in this manner, only one pulse in a series thereof should be applied to the coil of any given relay. In particular, once the delay switch associated with a relay has opened the holding circuit thereof, the coil of that relay should not receive further pulses from the ditferentiator 30. Otherwise, the system may not completely reset to the initial position, i.e., with all relays de-energized, if the period of one of the delay switches is exceeded by the interval between successive input pulses.
This is accomplished by means of the normally closed contacts 40d 42d, which are closed only when all of the relays following the first relay 38 are de-energized. When any one of the following relays is energized, a contact in the chain from 40d to 42d is open and thus input pulses are prevented from reaching the coil 38a. The circuit through the coil 38a can then be completed only after all the other relays are de-energized.
It will be apparent that with operation in the manner described above, it is highly unlikely that noise passed by the differentiator 30 can operate the impulse switch 22.
FIG. 2 illustrates a modification of the system of FIG. 1 providing for operation of the switch 22 without removing the home telephone from it cradle. This is accomplished by means of a relay stage, generally indicated at 60, following the stage 34. The stage 60 includes a relay 62 provided with a coil 62a, a normally open holding contact 62b and a normally open carry contact 62c. The holding contact 621) is in series with a delay switch 64 and the normally closed contact 66b of a relay 66, between the battery 46 and the coil 62a, An isolating resistor 68 between the relay stage 34 and the coil 62a isolates the stage 34 from the holding circuit of the relay 62. The holding circuit for the relay 62 also operates a double throw delay switch 70 having a thermal element 70a parallel with the coil 62a. The switch 70 includes a transfer contact 70b which is normally closed to a contact 700 and transfers to a contact 70d after the thermal element 70a has been energized for a predetermined length of time. By way of example, passage of current through the element 70a for a period :of 15 seconds may be required to move the transfer contact 701; from the contact 700 to the contact 70d.
When the coil 62a is energized :by a signal from the relay stage 34, the contacts 62c and 62b close and the current through the contact 62b holds the relay 62. If the ditferentiat-or 30 then emits a second signal within 15 seconds after the signal which energized the relay signal 62, i.e., before the transfer contact 70b has shifted to the contact 70d, the later signal will pass through the carry contact 620 and the contacts 70b and 700 to energize the coil 66a of the relay 66. This will open the contact 66b, thereby releasing the relay 62 and resetting the entire relay chain.
On the other hand, if the next signal arrives after an interval of 15 seconds, but before 45 seconds have passed, the contact 70b will have switched to the contact 70d and the signal Will therefore be passed to the following relay stage 72. The stage 72 may be similar to the stages 34 and 36; thus, it is energized by a signal arriving from the stage 60 and it then passes a succeeding signal from the differentiator 30 to the next relay in the chain.
If, after the relay 62 is energized, there is no signal within the next 45 seconds, the delay switch 64 will open, thereby interrupting the holding circuit for the relay 62 and releasing the relay.
Operation of the system with the modification of FIG. 2 is as follows. First, assume that the home telephone station 14 (FIG. 1) does not include apparatus for removing the telephone hand set from its cradle. In this case, the transducer 16 is merely the annunciator or bell incorporated in the station 14 and the transducer 18 thus picks up as its input signals the telephone rings emitted by the transducer 16. The time constants associated with the rectifier-filter 28 and diiferentiator 39 are such as to provide a single output pulse for each ring of the telephone. Moreover, the delay switches 48 and 52 are preferably set to hold the relays associated with them for an interval slightly in excess of the period of the telephone rings after the relays have been energized.
The operator of the system thus dials the home station 14 and allows the station 14 to ring three times. The first ring actuates the relay stage 32 and the second ring actuates the stage 34.
Returning to FIG. 2, the third ring results in a signal which is passed by the relay stage 34 to the stage 60 to energize the relay 62.
The user then hangs up at the remote station 12 to interrupt the succession of ringing signals at the home station 14. He follows this by immediately re-dialing the number of his home station and ringing signals are once again emitted by the transducer 16. However, by this time, the transfer contact 70b has shifted to the contact 70d and the first ringing signal causes a pulse to be passed through the contacts 62c and 70d to the relay stages 72. Succeeding signals are passed to successive relay stages in the manner described above until the stage 36 and then the impulse switch 22 are energized.
If a caller other than the user dials the station 14, the stage 60 will prevent the resulting signals from actuating the impulse switch 22. Specifically, the third ring will energize the relay 62 as described above. However, the fourth ring (occurring because the user of the system is away from home and therefore his telephone is unanswered) will occur before the contact b has transferred to the contact 70d. The corresponding signal from the differentiator 30 will therefore be passed to the relay coil 66a to open contact 66b and thereby release the relay 62. This will reset the entire relay chain so that, as described above, the next ringing signals will be applied to the relay stage 32 (FIG. 1).
If a caller should hang up immediately after the relay 62 has been energized, an unlikely occurrence, operation of the delay switch 64 will release the relay 62 to reset the system. That is, the switch 64 can be set to operate shortly after the time interval required for the user to hang up and dial his home telephone again after actuation of the relay 62. Thus, it willjust about ialways reset the system in time to prevent unwanted operation of the switch 22.
The embodiment of the invention shown in FIG. 2 is not restricted to use with telephone rings. It can be used with a home telephone station 14 incorporating a device for removing the hand set from its cradle. In that case, the user at the other end of the line dials the station 14 and, after the handset has been removed from its cradle he first emits the required number of sounds to actuate the relay 62. Next he pauses to permit operation of the delay switch 70, after which he emits the number of sounds required to operate the stages 72 36 (FIG. 2) and then operate the impulse switch 22.
The delay switch 56 is the relay stage 36 is set so that it ordinarily prevents a net change in the condition of the switch 22 by someone other than the user of the system, even if a signal should somehow get through to this stage. The first signal passed by the stage 36 operates the switch 22 as noted above. If a second signal is then received within the normal interval between such signals, it will also actuate the switch 22, thereby returning it to its previous state. The delay switch 56 will then reset the system so that a third section signal wlil not reach the switch 22.
A somewhat more elaborate arrangement in the final relay stage 36 will provide greater certainty of an unchanged condition of the switch 22. For example, an additional relay might be incorporated in such manner as to be energized by the signal passed by the relay 42 in the stage 36 and then held. After a fairly long interval during which no further signal is received, a simultaneously energized delay switch would deliver a pulse from the battery 46 through normally open contacts of this further relay to the impulse switch 22. If a further signal were passed by the relay 36 during this intervn-al, it would be used to open the holding circuit for the additional relay in much the same manner as actuation of the relay 66 opens the holding circuit of the relay 62.
It will be apparent that audible signals are not the only signals which can be used to operate the system. Acoustical signals of any frequency can be used, although, in general, sensitivity to audible signals will lead to the most practical arrangement. Moreover, the underlying principles 0f the invention may be applied to signals which do not make use of acoustical media. Thus, one may use electrical signals applied directly to the amplifier 26 or rectifier-filter 28, or the transducer 18 may be sensitive to energy in other forms, such as light energy. In the latter case the system would be operated by a series of flashes of light.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above constructions without departing from 7 the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not ina limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
1. Apparatus for remote control of an appliance or the like, said apparatus comprising (A) means for detecting input signals emitted by a user of the system and supplying countable signals in response to said input signals,
(B) first counting means for counting said countable signals and supplying an intermediate signal when the number of said countable signals reaches a first predetermined number, said intermediate signal being the next countable signal after said first number,
(C) second counting means,
(D) intermediate relay means responsive to said intermediate signal and arranged to pass countable signals successive thereto to said second counting means if -a first interval between said intermediate signal and the first of said successive countable signals is greater than a first value and less than a second value,
(E) said second counting means providing an output signal after a predetermined number of countable signals have been counted thereby, and
(F) power switching means connected for actuation by said output signal.
2. The combination defined in claim 1 in which each of said counting means includes means for resetting said apparatus when the interval between successive countable signals counted thereby is greater than said first value.
3. The combination defined in claim 1 in which (A) said detecting means includes means for detecting signals emitted by a first'telephone substation,
(B) said first value is slightly greater than the interval between countable signals corresponding to ringing signals emitted by said first substation,
(C) said second value is slightly greater than the time required for the user at a second substation remote from said first substation having first dialed said first substation to cause said ringing signals to cease and then to bring about further ringing signals by redialing said first substation.
4. The combination defined in claim 3 in which of said counting means includes means for resetting said apparatus when the interval between successive countable signals counted thereby exceeds the period of said ringing signals by a predetermined amount.
References Cited UNITED STATES PATENTS 1,867,209 7/1932 Chauveau 340-164 2,600,648 6/ 1952. Herrick 340-164 2,811,708 10/1957 Byrnes et al. 340 -164 3,280,259 10/1966 Cotter 1792 3,308,239 3/1967 Waldman et a1 1792 30 THOMAS B. HABECKER, Acting Primary Examiner.
NEIL C. READ, Examiner.
H. I. PITTS, Assistant Examiner.