WO1989011194A1

WO1989011194A1 - Remote on/off telephone switching system

Info

Publication number: WO1989011194A1
Application number: PCT/GB1989/000498
Authority: WO
Inventors: Jon M. Newton; David A. Caswell
Original assignee: Canadian Communications Innovations Inc.
Priority date: 1988-05-10
Filing date: 1989-05-10
Publication date: 1989-11-16
Also published as: AU3567189A

Abstract

A remote on/off switching system (10) for coupling to the telephone lines (14) at a location is provided. The system includes at least one switching circuit (300) connected between a household circuit (400) typically in the form of an appliance and a household power supply (500). The switching circuits are actuable between open and closed positions upon reception of control signals to connect or disconnect the household circuits to the power supply. A telephone line interface (100) is included for detecting and answering incoming telephone calls. A microcontroller (210) communicates with the telephone line interface and allows a user to access the system upon receipt of a valid security code. Upon access of the user to the system, the user can command the microcontroller to generate control signals to actuate a specific switching circuit between its open and closed positions or to inform the user of the position of the switching circuits. When the user conditions the microcontroller to actuate a switching circuit, the microcontroller also informs the user of the off/on status of the switching circuit.

Description

REMOTE ON/OFF TEUIPHONE SWITCHING SYSTEM

The present invention relates to a remote on/off switching system.

Presently, when it is desired to turn an ; appliance in a location on or off, the appliance must be connected or disconnected to its power source by throwing the appropriate switch. This process is satisfactory when a person is in the proximity of the switch, or when a person does not require any appliances to:, be. connected or disconnected to a power supply when the; location is vacant.

However, often it is desired to turn an appliance on before arrival at the location. It is also ^" desirable to be able to check the status of appliances when the location is vacant. Although devices to perform remote switching of appliances have been attempted, they have not satisfactorily met the requirements of the consumer.

It is therefore an object of the present invention to provide a novel remote on/off switching system.

According to the present invention there is provided a remote on/off switching system for connecting to the telephone lines at a location comprising: at least one switching means for connecting between a location circuit and a power supply, said switching means being actuable between closed and open positions upon reception of control signals to connect and disconnect said circuit to said power supply; telephone call detection means for detecting and answering^' incoming telephone calls; and control means communicating with said telephone call detection means and said switching means, said control means including security code detection means for detecting a security code entered by a user 5-^r from a remote location, said security code detection means allowing said user to access said system upon receipt of a valid security code and command detection and response means responsive to said security code detection means and being operable to detect commands 0 entered by said user upon receipt of said valid security co ®, said command detection and response means also being operable to indicate to said user the position of said switching means and to generate said control signals to actuate said switching means between said

15 positions upon receipt of commands from said user.

Preferably, the remote switching means communicate with the control means via a hardwire link. Each of the switching means preferably comprises an

20. opto-coupler and a relay, the opto-coupler energizing the relay to actuate a switch to a closed position upon receipt of the control signals. The switch in the closed position connects the location circuit to the power supply.

25

Preferably, the control means comprises a DTMF decoder for converting analogue signals received over the telephone lines into four-bit binary words and a microcontroller which includes appropriate software- for

30 interpreting the commands received from the user and for detecting the security code. It is also preferred that the security code and commands be entered as tone sequences and are generated by the user simply by depressing appropriate buttons on a touch-tone telephone. Preferably, the control means also includes a voice player for audibly informing the user of the position of the switching means upon request of this information from the user. ' 5

The present system provides advantages in that the household circuits connected to a switching means can be activated or de-activated by a user at a remote location simply by making a telephone call to the

10^'. location and entering the appropriate touch tone security code and commands. In this manner, for example, furnaces and water heaters can be turned on at cottages supplied with the present system prior to the arrival of the user at the cottage. Furthermore, the

15 status of appliances at a location supplied with the present system can be monitored when the location is vacant to ensure that all appliances are off.

Embodiments of the present invention will now 20^" be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a block diagram of a remote on/off switching system; 22r Figure 2 is a circuit diagram of a portion of the system illustrated in Figure 1;

Figure 3 is a circuit diagram of another portion of the system illustrated in Figure 1;

Figure 4 is a circuit diagram of an element of 330: the portion illustrated in Figure 3;

Figure 5 is a circuit diagram of another element of the portion illustrated in Figure 3; ' Figure 6 is a circuit diagram of still yet another element of the portion illustrated in Figure 3;

SUBSTITUTESHEET Figure 7 is a circuit diagram of another portion of the system illustrated in Figure 1;

Figure 8 is a circuit diagram of still yet another portion of the system illustrated in Figure 1; Figures 9a, 9b and 9c are a functional block diagrams illustrating the function performed by the portion illustrated in Figure 7;

Figures 10a and 10b are circuit diagrams of an alternate embodiment of portions of the system illustrated in Figure 1; and

Figures 11a and lib are circuit diagrams of yet another embodiment of the portions illustrated in Figures 10a and 10b.

Referring to Figure 1, a remote on/off switching system 10 is shown. The system includes a telephone line interface 100 for connection to the incoming telephone lines 14a of a location and for connection to the outgoing telephone lines 14b supplying other telephones or an answering machine at the location. The telephone line interface 100 detects incoming telephone calls from a user and changes information in the form of tone sequences received from the user into digital signals. The digital signals generated fay the telephone line interface 100 are then conveyed to a controller 200. The controller 200 interprets the digital information received from the telephone line interface 100 and allows access of the user to the system 10 when a valid security code is received.

The controller 200 is also connected to a plurality of switching circuits 300. The switching circuits 300 are connected between a household circuit 400 typically in the form of an appliance and a household power supply 500 which supplies the power to the household circuit 400. The switching circuits 300 function to connect or disconnect the household circuit ' 5 400 from the household power supply 500 upon reception of control signals from the controller 200. The controller 200 also outputs information to the user via a digital voice player or voice synthesizer 600 and the telephone line interface 100 to inform the user of the

10; position of the switching circuits 300 and to inform the user as to which household circuit 400 is being activated or de-activated when a switching circuit 300 receives the control signals. A system power supply 700 is also provided for supplying power to the telephone

15 line interface 100, the controller 200, the switching circuits 300 and the voice player 600.

The system power supply 700 is better illustrated in Figure 2 and is connected to the

20 household power supply 500 via suitable connectors. The system power supply 700 includes a typical 120 volt AC to 12 volt AC transformer 710 having its primary coil 712 connected to the household power supply 500. The secondary coil 714 of the transformer 710 is coupled to

25?, a full-wave bridge rectifier 720. A capacitor 730 is connected between the output of the rectifier 720 and the ground G and acts as a filter for the 12v supply voltage. A 12^v power supply pin 740 is also connected to the output of the rectifier 720 and provides a 12v

30. supply voltage to components in the system 10. The 12v supply voltage is also conveyed to a 5 volt voltage regulator 750 via a resistor 760. The resistor

_Λ functions to lower the voltage of the supply before it is received by the regulator 750. A second capacitor 770 is connected between the output of the regulator 750 and the ground G and acts as a filter for the 5v supply voltage. A 5^V power supply pin 780 is also connected to the output of the regulator 750 and provides a 5v supply voltage to components in the system 10. Since it is believed that the operation of the system power supply 700 is well known to those of skill in the art, details thereof will not be discussed herein.

The telephone line interface 100 is shown in

Figures 3 to 6 and comprises two modular telephone plugs 02, 104 respectively. One plug 102 engages with the incoming telephone lines 14a and the other plug 104 engages with the outgoing telephone lines 14b. Two output leads 102a, 102b extend from the plug 102 and are interconnected via a capacitor 106 and a metal oxide varistor 108. The capacitor 106 functions to protect the interface circuitry against short duration voltage spikes on the incoming telephone lines 14a whilst the varistor 108 protects the interface circuitry from high voltage surges on the incoming telephone lines 14a.

A full-wave bridge rectifier 110 is connected to the lead 102a and to a current detect circuit 140 and provides an output signal to an input lead of a relay 112 by way of conductor 113. The other input leads of the relay 112 are directly connected to the lead 102b via conductor 114 and to the controller 200 via conductor 116. The output leads of the relay 112 are connected to the modular plug 104. The relay 112 is conditioned by the controller 200 to remain typically in a closed condition so that the plug 104 is connected to the leads 102a and 102b. This permits telephones and answering machines in the location to detect incoming telephone calls.

The rectifier 110 also provides input signals ^" to a relay 118 which is typically in an open condition.

The relay 118 receives control signals from the controller 200 via conductor 120 which causes the relay 118 to move to a closed position. When this occurs, signals provided on the leads 102a,102b are transferred tc a controller and voice interface circuit 160 via the relay 118. The controller and voice interface circuit 160 communicates with the controller 200 via a bus 121 and conductors 122 and 124 and with the voice player 600 via conductor 125.

A ring detect circuit 180 is also connected across the output leads 102a and 102b and provides an output signal to the controller 200 via conductor 126 when an incoming telephone call is received on the telephone lines 14a. The current detect circuit 140 also provides output signals to the controller 200 via conductor 128 when a telephone in the location is detected as going "off-hook" or when an answering machine responds to an incoming telephone call. ^'

The ring detect circuit 180 is better illustrated in Figure 4. As can be seen, the ring detect circuit 180 includes a conductor 182 extending from lead 102a. A capacitor 184 and a resistor 186 are ^*. connected in series with the conductor 182. One terminal of the resistor 186 is connected to the cathode of a zener diode 188 which has its anode connected to the anode of another zener diode 190. The cathode of the zener diode 190 is connected to the cathode of a

SUBSTITUTE SHE≡^" diode 192 and to the anode of an LED 194a forming part of an opto-coupler 194. The anode of the diode 192 and the cathode of the LED 194a are connected to a conductor 196 which extends to the lead 102b. The opto-coupler 5 194 also includes a transistor 194b which is in communication with the LED 194a. The collector of the transistor 194b is connected to the 5^V supply pin 780 of the power supply 700 via resistor 198 and to the conductor.126. The emitter of the transistor 194b is 0 connected toe the ground G.

The current detect circuit 140 as is illustrated in Figure 5 comprises five diodes 141 to 145 connected in series across a pair of conductors 146 and 5 148 respectively. The conductor 146 extends from the positive output of the bridge rectifier 110 to the anode of an LED 150a forming part of an opto-coupler 150 via a resistor 152. The cathode of the LED 150a is connected to the conductor 14.8 which extends to the negative 0 output of the bridge rectifier 110. A transistor 150b forming the other part of the opto-coupler 150 is in communication with the LED 150a. The collector of the transistor 150b is connected to the 5*^" supply pin 780 of the power supply 700 via resistor 154 and to the 5^' conductor 128. The emitter of the transistor 150b is connected to the ground G.

The controller and voice interface 160 is better" illustrated in Figure 6 and includes a pair of 30. conductors 161 and 162 which extend from the relay 118. The conductors 161,162 are connected to the leads 102a and 102b respectively via the relay 118 when the relay receives a control signal from the controller 200 via conductor 120. An audio transformer 163 has its primary coil 163a connected across the conductors 161 and 162 via resistors 164 and 165 respectively.

The secondary coil 163b of the transformer 163 » 5 has its output leads interconnected via a pair of zener diodes 166,167 connected in series. The zener diodes 166,167 are arranged so that the anodes of each zener diode are interconnected. A conductor 169 extends from one terminal of the transformer secondary coil 163b and 10 is connected to the ground G via a resistor 170. A capacitor 171 has one of its terminals connected to the conductor 169 and the other of its terminals connected to the analogue input pin AIN of a DTMF decoder 172.

15 The other terminal of the transformer secondary coil 163b is connected to the ground G via a pair of capacitors 173,174 interconnected by a conductor 175. The output terminal of an amplifier 176 is connected to conductor 175. The inverting terminal of

20 the amplifier 176 is connected to the ground G while the non-inverting terminal of the amplifier 176 is connected to a potentiometer 177. The potentiometer 177 has one of its other terminals connected to the ground G and its third terminal connected to conductor 125 via a

25 capacitor 178.

The DTMF decoder 172 functions to convert the analogue signals received on the AIN pin into digital information. The digital information is outputted from S the decoder 172 on the Dl, D2, D4, and D8 terminals and conveyed to the controller 200 via the bus 121. The DTMF decoder 172 also generates a signal on its DV terminal which is conveyed to the controller 200 via conductor 122 prior to outputting the digital information on bus 121 to inform the controller 200 that a digital word is being outputted by the decoder 172. The XIN pin of the DTMF decoder 172 receives clocking signals from the controller 200 via conductor 124 whilst 55 the VCC, XEN and EN pins of the decoder 172 are connected to the 5^V power supply pin 780.

The controller 200 is shown in Figure 7 and includes a single Chip MC68705 microcontroller 210

10 manufact red by Motorola which receives the output of the-DTMF decoder 172 via the bus 121 and conductor 122. The microcontroller 210 is provided with appropriate software for recognizing the four bit binary words received from the DTMF decoder 172 via bus 121 and for

15. allowing a user to operate the switching circuits 300 when a correct security code has been received as will be described herein. The microcontroller 210 includes a port 220 which is configured as a data bus 222 that is connected to the voice player 600. The microcontroller

20r also includes a plurality of output lines 223 which provide control signals to the voice player 600. A 74L573 gate latch 224 is also connected to the bus 222 as well as to each of the switching circuits 300.

25 The microcontroller 210 further includes a plurality of input pins for receiving the signals provided on the bus 121, and conductors 122, 126 and 128 respectively as well as a plurality of output pins for conveying signals onto conductors 116 and 120.

30:

The controller 200 also includes a clock generator 240 comprising a crystal 242, a hex invertor chip 244 including six invertors 244a to 244f, a resistor 246, and a resistor 248. The clock generator 240 produces clocking signals which are outputted via three of the invertors 244a, 244b and 244σ. The output

• of the invertor 244a is conveyed to the voice player 600 via conductor 260. The output of invertor 244b is

^* 5 conveyed to the decoder 172 via conductor 124 and the output of the invertor 244c is conveyed to the microcontroller 210 via conductor 262.

The microcontroller 210 stores in its memory, 10 a pre-programmed start code along with a pre-programmed security code for comparison with the start and security codes entered by the user. The microcontroller also stores a plurality of pre-programmed messages. The microcontroller 210 also stores a pre-programmed list of 15 switching circuit identification codes, each identification code comprising three 4-bit binary words. Each identification code is associated with one of the switching circuits 300 at the location. A plurality of messages are associated with each identification code 20 and are outputted to the user via the voice player 600 when the user is operating the switching circuits 300.

Referring to Figure 8, one of the switching circuits 300 is shown. The switching circuit 300

25 includes a first pair of leads 302,304 extending from the household power supply 500 to the household circuit 400. A switch 306a forming part of a relay 306 is provided on the lead 302 and is operable between open and closed positions for disconnecting and connecting

30 the household power supply 500 to the household circuit 400. The relay switch 306a is typically in an open position and moves to a closed position when the coil 306b of the relay 306 is energized.

UB TITUTESHEET One terminal of the relay coil 306b is connected to the 12^v supply pin 740 of the system power supply 700 while the other terminal is connected to the collector of a transistor 308b forming part of an opto- coupler 308. A diode 310 is connected across the terminals of the coil 306b along with a series circuit 312 comprising a resistor 314 and an LED 316. The emitter of the transistor 308b is connected to the ground G. An LED 308a forms the other part of the opto- coupler 308 and has its anode connected to the 5^V power supply pin 780 of the system power supply 700 via a resistor 318. The cathode of the LED 308a extends to the controller 200 via conductor 320.

: The operation of the system will now be described with reference to Figures 1 to 9. When the system power supply 700 is connected to the household power supply 500, the secondary coil 714, is energized via the primary coil 712. The stepped down AC voltage - is then applied to rectifier 720 which in turn outputs a 12v DC voltage. The DC voltage is then filtered and conveyed to output pin 740 as well as being stepped down and regulated to 5 volts. The 5v supply is also filtered and then applied to supply pin 780. The power 5 supply pins 740 and 780 in turn supply the required 12v and 5v supply voltages to the various components in the system 10. With this power initialization complete as shown at block 1000 of Figure 9a, the microcontroller 210 monitors the input pin thereof connected to 1 conductor 126 to detect any incoming telephone calls as indicated at block 1010.

When an incoming telephone call is received on the telephone lines 14a, intermittent ringing signals

SUBSTITUTESHEET are received by the system 10. Each ringing signal passes across the modular plug 102 onto leads 102a and 102b. Each ringing signal is conveyed towards relay 118 via rectifier 110. Since the relay 118 is typically in an open condition, the incoming call ringing signal does not pass to the controller and voice interface 160. Each ringing signal does, however, pass along conductors 113 and 114 to relay 112. Since relay 112 is typically in a closed position, each ringing signal passes to the plug; 104 so that the incoming call can be detected by telephones in the location or by an answering machine.

Each incoming ringing signal also passes to conductors 182 and 196 of the ring detect circuit 180. The voltage of each ringing signal is then dropped via the zener diodes 188, 190 and resistor 186. However, the voltage of each ringing signal is still sufficient to bias the LED 194a of the opto-coupler 194 into a "on" condition. The light emitted by the LED 194a is received by the base of transistor 194b causing the transistor turn on. With the transistor 194b on, current is allowed to flow from the supply pin 780 to the ground G via resistor 198 and transistor 194b. This current flow also provides a logic "high" on conductor 126 which is conveyed to the microcontroller 210. Since each ringing signal is of short duration, the microcontroller 210 is supplied with a pulse for each ringing signal received.

The pulses generated by the circuit 180 are received by the microcontroller 210 via conductor 126 and counted as shown by block 1030. If the microcontroller 210 detects that the incoming telephone call has been answered as shown by block 1020, the

SUBSTITUTESHEET microcontroller 210 inhibits the counting function. This loop continues as shown by arrow 1035 and block 1030 until the number of ringing signals detected by the microcontroller 210 reaches a pre-determined number or until the incoming telephone call is answered by lifting the handset of a telephone or by an answering machine. When the number of detected pulses applied to the conductor 126 from circuit 180 reaches the pre¬ determined number, the microcontroller 210 provides a control signal to conductor 120. The control signal applied to conductor 120 is conveyed to.the relay 118 causing it to move to a closed position thereby connecting the controller and voice interface 160 to the leads 102a and 102b as is shown by block 1040. However, if the microcontroller 210 detects that the incoming telephone call has been answered, the microcontroller 210 also provides the control signals to the relay 118 via the conductor 120 to connect the controller and voice interface 160 to the leads 102a, 102b as is indicated by arrow 1045 and block 1040.

To detect whether the incoming telephone call has been answered, the microcontroller 210 monitors the input pin thereof connected to conductor 128 extending from the current detect circuit 140. When a telephone or answering machine at the location answers the incoming telephone call by going to the "off-hook" condition, current flows through the rectifier 110 and onto conductor 146. The provision of the five diodes 141 to 145 provides a sufficient voltage drop across conductors 146 and 148 to bias the LED 150a of the opto- coupler 150 to an "on" condition. The conductor 148 provides a return path for the current flow. With the LED 150a on, the transistor 150b is supplied with light thereby causing it to conduct. With transistor 150b in operation, current flows from supply pin 780 to the ground G via resistor 154 and transistor 150b. This current flow results in a logic "high" being supplied to 5 conductor 128 which is detected by the microcontroller 210 thereby informing the microcontroller 210 that the telephone call has been answered.

With the controller and voice interface 160 Qj connected to the leads 102a, 102b via relay 118, the microcontroller 210 examines the input leads from the bus 121 and the conductor 122 to detect a digital start code as is shown by block 1060. In this case for example, the digital start code is generated by the 5: decoder 172 when the "#" key of a touch-tone telephone is depressed by the caller and the resulting tone is received on the AIN pin of the decoder 172. The microcontroller 210 continuously monitors the bus 121 and conductor 122 for a pre-determined amount of time as 0 shown by block 1070 and arrow 1075. If the start code is not received by the microcontroller 210 within the pre-determined amount of time, the microcontroller 210 removes the control signal from relay 118 thereby isolating the controller and voice interface 160 from 5 the leads 102a, 102b as is illustrated by block 1080.

The microcontroller 210 then reverts back to block 1010 and awaits receipt of another incoming telephone call as shown by arrow 1090. In this manner, if an incoming call is answered by an answering machine at the location O and the caller is unaware of the system 10, the system 10 remains transparent to the caller and the answering machine functions in a typical manner to record a telephone call. The above routine is also employed when a person at the location answers an incoming call using

SUBSTITUTE SHEE a telephone at the location and the caller is unaware of the system 10.

However, if the caller enters the start code 5 within the pre-set time by depressing the appropriate key on a touch-tone telephone, the resulting tone is conveyed along the telephone lines 14a and received on leads 102a,102b via the plug 102. Since the relay 118 is connected to the leads 102a,102b, the tone passes lύ- onto conductors 161,162 and is passed across the audio transformer 163. The touch-tone is then filtered via capacitor 171 and resistor 170 and applied to the AIN pin of the decoder 172. The decoder examines the tone and assigns the tone a 4-bit digital word. Prior to the

15 word being outputted to the microcontroller 210 via the bus 121, the decoder 172 firstly applies a signal onto conductor 122 via the DV pin thereof to inform the microcontroller that a digital word is being applied to the bus 121. The digital word is then applied to the

20 bus 121. The decoder 172 functions in this manner for every touch-tone received on the AIN pin thereof that is generated by the caller.

The microcontroller 210 compares the received 25 4-bit word with the pre-programmed start code stored therein and if the start code is correct, conveys signals to the voice player 600 which causes the voice player 600 to output an introduction message to the controller and interface circuit 160 as shown by block 30 1100. The message is conveyed to the voice player 600 as digital data which is converted into a voice message via voice synthesis. The audio message in turn is supplied to conductor 125 and conveyed across the audio transformer 163 via amplifier 176. The message then passes along conductors 161, 162 and across the relay 118 wherein it propagates along leads 102a, 102b to the plug 102. From the plug 102, the message is transmitted to the caller via the telephone lines 14a thereby informing the caller that the system 10 is now awaiting receipt of a valid security code. Once the start code has been received and verified, the microcontroller 210 removes the control signal from conductor 116. This causes the relay 112 to move to an open condition ^" thereby disconnecting the telephones and answering machines at the location from the leads 102a,102b regardless of their operating condition.

The security code verify routine is ^" illustrated in Figure 9b. Once the message has been transmitted to the caller, the microcontroller 210 monitors the bus 121 for the receipt the proper four 4- bit binary words that will be generated by the decoder 172 if the caller enters the 4 tone sequence representing the security code. If the microcontroller 210 detects that no tones have been entered by the caller within a preset time, the microcontroller 210 removes the control signal from the relay 118 thereby disconnecting the controller and voice interface 160 3 from the leads 102a, 102b and terminating the connection of the caller to the system 10 as is shown by blocks 1120, 1130, 1140. Thereafter, the microcontroller 210 reverts back to block 1010 and awaits receipt of the next incoming telephone call. :

If the microcontroller 210 detects that a tone has been entered by the caller due to the receipt of a 4-bit word via bus 121, the microcontroller 210 waits until four digital words have been received from the

SUBSTITUTESHEET decoder 172 as is shown by blocks 1120 and 1150 and arrow 1160. Once four digital words have been generated by the decoder 172 in response to received touch-tones generated by the caller, the received digital words are compared with the pre-programmed security code stored in the microcontroller 210 as shown by block 1170. If the entered security code is detected as being incorrect, a counter is incremented and the microcontroller 210 reverts back to block 1120 and awaits receipt of four more digital words from the decoder 172 or until a time out occurs as is shown by block 1180 and arrow 1190. If the number of incorrect security codes entered by a caller exceeds three, the microcontroller 210 removes the control signal from conductor 120 thereby opening relay 118 and isolating the controller and voice interface 160 from the leads 102a, 102b as is shown by blocks 1180, arrow 1200 and block 1140. If this occurs, the microcontroller 210 reverts back to block 1010 and awaits receipt of the next incoming telephone call. -=

If however, a valid security code is entered by the caller and verified by the microcontroller 210, the microcontroller 210 allows the caller to access the system 10 and allows the caller to check the status of ^" the switching circuits 300 in the location as well as allows the user to change the condition of the switching circuits 300 in the location as will be described.

As soon as the entered security code has been " verified, the microcontroller 210 examines the status of the latches 224 to determine the on/off status of each of the switching circuits 300 at the location. Once this is done, the microcontroller 210 conveys the status information to the voice player 600 which in turn

SUBSTITUTESHEET generates an audio message. The message is presented it to the caller in the manner previously described via the controller and voice interface 160 thereby informing the caller of the position of every switching circuit 300 in the location as indicated by block 1210.

Once the caller has been given the switching circuits status, the microcontroller 210 monitors the bus 121 awaiting receipt of further digital words generated by the decoder 172 in response to touch-tone commands entered by the caller as is shown by block 1220. If no digital words are received by the microcontroller 210 within a preset time, the microcontroller 210 removes the control signal from conductor 120 thereby opening relay 118 and isolating the controller and voice interface 160 from the leads 102a, 102b as is shown by blocks 1230 and 1240. When this occurs, the microcontroller 210 reverts back to block 1010 an awaits receipt of the next incoming call.

If a tone is received by the system 10 due to the depression of one of the touch-tone keys by the caller, the microcontroller 210 checks to see whether the entered touch-tone key is a 1 to 9 digit key by comparing the generated digital word with corresponding words stored in the memory therein (block 1250). If the digital word received by the microcontroller 210 is generated as a result of the tone produced when depressing a number 1 to 9 digit key, the digit is stored in a buffer as shown at block 1260. If less than three digital words have been received by the microcontroller 210, the microcontroller 210 awaits receipt of additional words until three words have been received as indicated by block 1260 and arrow 1270. If

SUBSTITUTESHEET three words are entered and each results from the depression of a number key from 1 to 9, the buffer storing the digital words is cleared (block 1280) and the microcontroller 210 reverts back to block 1220 and 5 awaits receipt of a proper three digital word code.

If the caller depresses the "*" or enter key on the touch-tone phone, the microcontroller 210 checks the bu fer to determine whether any digital words are 0 stored therein as shown by blocks 1290 and 1300. If no digital words have previously been received by the microcontroller 210 and stored in the buffer, the global status report is reported to the caller again in the manner described above (block 1310). Thereafter, the

15- microcontroller 210 reverts back to block 1220 and awaits receipt of more digital words generated by the decoder 172. However, if a digital word or words is/are located in the buffer, the microcontroller 210 examines the stored digital words and compares them with the

20. switching circuit identification codes stored therein. When a match is detected, the microcontroller 210 provides a signal to the latch 224 which causes the latch to change the logic value of the signal applied to the conductor 320 that is connected to the switching

25 circuit 300 associated with the entered identification code. This causes the switching circuit 300 associated with the entered code to switch to the opposite condition as will be described.

30 Once the switching circuit 300 status has changed, the microcontroller 210 supplies data to the voice player 600 which causes the voice player to generate an audio message informing the caller of the new status of the actuated switching circuit 300 (block

SUBSTITUTESHEE" 1320). Once this is done, the microcontroller 210 clears the buffer and reverts back to block 1220 to await receipt of the next digital word generated by the decoder 172.

If the "#" or cancel key is entered by the caller, the microcontroller 210 checks the status of the buffer to determine whether any words have previously been stored therein (blocks 1330 and 1340). If no digits have previously been entered, the cancel key is construed to mean that it is desired to terminate the session. The microcontroller 210 in turn removes relay 118 from the leads 102a, 102b in the manner previously described (block 1350) and the microcontroller 210 reverts to block 1010 and awaits receipt of another incoming call. However, if the buffer is detected as having at least one word stored therein, the microcontroller 210 clears the buffer (block 1360) and reverts back to block 1220 to await receipt of the next digital word generated by the decoder 172.

When the caller enters at least one 1 to 9 digit tone and the enter tone thereby generating an identification code, the switching circuit 300 associated with that identification code is actuated to it's opposite position as discussed above. This is achieved by either removing the logic high supplied to conductor 320 or by applying the logic high to the conductor 320. The removal of the logic "high" signal on conductor 320 allows a control current to flow from the supply pin 780 to the controller 200 via the resistor 318, LED 308a, conductor 320 and latch 224. The control current and resulting potential voltage across the LED 308a, energizes the LED 308a of the opto-

SUBSTITUTESHEET coupler 308 causing it to emit light which is received by the transistor 308b. The transistor 308b in turn conducts and allows current to flow from the supply pin 740 to the ground G via resistor 314, LED 316 and the transistor 308b. The current flow through the LED 316 causes it to illuminate giving a visual indication that the switching circuit 300 is operating. The current flow also passes to the ground G via the relay coil 306b and the transistor 308b. The current flow through the cσil 306b causes it to energize thereby closing the switch 306a. With the switch closed, the household circuit 400 becomes connected to the household power supply 500 and is operational.

If however, a logic "high" is applied to the conductor 320 via the microcontroller 210 and the latch 224, the potential voltage applied across LED 308a is removed thereby inhibiting the operation of transistor 308b. This prevents current flow through the coil 306b -thereby causing the switch 306a of the relay 306a to open and thus, removing the household circuit 400 from the household power supply 500. When this occurs, the diode 310 provides a discharge path for the residual energy stored by the coil 306b when it is removed from the current flow.

Referring now to Figures 10a and 10b, alternative embodiments of the controller 200' and the switching circuits 300' are shown. In these embodiments, like reference numerals will be used to indicate like components with a "'" added for clarity. As shown, the latch 224' is similarly coupled to a plurality of output lines 320' . However, the output lines 320' are connected to a multiple frequency

SUBSTITUTESHEET generator 380 as opposed to the switching circuits 300. The generator 380 generates a signal having a unique frequency for each output line 320' for as long as the generator 380 is supplied with a logic "high" on the output line. Each signal is associated with one switching circuit 300' and when a signal is produced by the generator 380, it is conveyed to an FM transmitter 382.

The switching circuits 300' of this embodiment include all of the components shown in Figure 8 and further comprise a FM receiver 384 coupled to a single frequency detector 386. The detector 384 provides the logic "high" control signal to inhibit operation of the opto-coupler 308' upon reception of the appropriate signal broadcasted by transmitter 382 throughout the location. When the FM broadcast of the frequency associated with a detector 386 located at a switching circuit stops, the^' opto-coupler 308' becomes operational allowing the household circuit 400 to be supplied by the household power supply 500.

Alternatively, the FM transmitter 382 and the FM receiver 384 can be coupled to the household power supply 500 so that transmission of the control signals can be conveyed to each switching circuit 300 via the household power lines 500 as opposed to being broadcasted throughout the location.

In yet a further embodiment as is illustrated in Figures 11a and lib, the controller 200'' can be provided with an FM transceiver 390 and a dual tone detector 392 in addition to the multiple frequency generator 380'. Furthermore, each switching circuit

SUBSTITUTESHEET 300' ' can be provided with an FM transceiver 394, a dual tone detector 396 and a dual tone generator 398. In this embodiment, the generator 380' generates a pair signals each having a unique frequency of for each 5 switching circuits 300' ' , the first signal for each circuit 300' ' being a status inquire signal and the second signal being a control signal.

In operation of this embodiment, the output 00 lines 320' ' are not continuously activated and thus, the microcontroller 210' is isolated, from the circuits 300' ' . To determine the status of a remote switching circuit 300' ' , the microcontroller 210' supplies the output line 320^? ' associated with the switching circuit

15 with a logic "high". The generator 380' receives the pulse and generates the appropriate inquire signal. The inquire signal is conveyed to the transceiver 390 and broadcasted to the switching circuit 300' ' . When the signal is received by the transceiver 394 it is detected

20. by the detector 396. The detector 396 in turn monitors the status of the switching circuit 300' ' to determine if the circuit is activated or not and supplies one of two signals to the generator 398. The generator 398 in turn generates one of two signals, each having a

25- different frequency depending on the signal received from the detector 396 and conveys the generated signal to the transceiver 394 wherein it is broadcasted to the transceiver 390. The detector 392 receives the signal from the transceiver 390 and depending on which signal

30 is received, informs the microcontroller 210' ' of the switching circuit status.

When it is desired to change the status of the switching circuit, the control signal associated with

SUBSTITUTESHEET the circuit is broadcasted and received at the remote circuit in the manner previously described. The detector 396 receives the control signal and connects or disconnects the cathode of the LED 308a to a potential voltage source to either inhibit or permit operation of the opto-coupler 308. As should be realized, this embodiment removes the need for the microcontroller to supply continuously signals to the output lines 320. Similarly, the FM transmissions of this embodiment can be conveyed over the household power lines 500 by coupling the FM transceivers thereto.

The present system allows appliances in a location to be operated from a remote location simply by making the appropriate telephone call and entering the correct start code, security code and commands. For example, this allows a user to operate furnaces, thermostats and water heaters prior to the arrival at a cottage. This system is also useful in allowing a user to operate cameras in closed-circuit surveillance systems where variable control is desired from remote locations. Moreover, the present system is completely transparent to a caller unaware of the installation of the system at the location and permits operation of the telephones or the answering machine at the location until a start code is entered.

The system is also useful in ensuring that appliances are turned off and are not left operating while unattended. Furthermore, the system can be used as a security measure since lights and other appliances can operated to give the impression that the location is occupied. Furthermore, since the status of appliances can be checked, unauthorized operation of an appliance

SUBSTITUTESHEET can indicate the presence of an intruder in the location.

It should be apparent to one of skill in the art that the present invention can be modified without departing from the scope thereof as defined by the appended Claims.

U&STITUTE S

Claims

We claim:

1. A remote on/off switching system for connecting to the telephone lines at a location comprising: at least one switching means for connecting between a location circuit and a power supply, said switching means being actuable between closed and open positions upon reception of control signals to connect and disconnect said circuit to said power supply; telephone call detection means for detecting and answering incoming telephone calls; and control means communicating with said telephone call detection means and said switching means, said control means including security code detection means for detecting a security code entered by a user from a remote location, said security code detection means allowing access of said user to said system upon receipt of a valid security code and command detection and response means responsive to said security code detection means and being operable to detect commands entered by said user upon receipt of said valid security code, said command detection and response means also being operable to indicate to said user the position of said switching means and to generate said control signals to actuate said switching means between said positions upon receipt of commands from said user.

2. The system as defined in Claim 1 wherein said telephone call detection means includes an analogue to digital decoder, said decoder receiving said security code and said commands in the form of tones and converting said tones into digital information for processing by said control means.

SUBSTITUTE SHEET 3. The system as defined in Claim 2 wherein said control means comprises a microcontroller in communication with said decoder, said microcontroller including memory means storing a pre-programmed security code and a list of valid commands, said microcontroller comparing said entered security code and commands with said entered code and commands to determine valid commands.

3 4. The system as defined in Claim 3 wherein each of said switching means is coupled to said microcontroller via a hardwire link, said microcontroller conveying said control signals thereover upon reception of said commands to actuate said 5 switching means between said positions.

5. The system as defined in Claim 4 wherein said switching means includes an opto-coupler coupled to a relay, said opto-coupler energizing said relay upon 0 reception of said control signals whereby energization of said relay operates a switch to connect said location circuit to said power supply.

6. The system as defined in Claim 1 wherein said telephone call detection means includes an amplification circuit, said amplification circuit amplifying information outputted by said control means prior to being transmitted to said user.

DT 7. The system as defined in Claim 1 wherein said control means further comprises a voice synthesizer for receiving the output from said control means and converting said output into a message prior to being transmitting to the user.

SUBSTITUTE SHEET 8. The system as defined in Claim 3 wherein said control means and said switching means are electrically isolated and said control means further includes broadcast means for broadcasting said control signals

5 and each of said switching means includes reception means for receiving said control signals.

9. The system as defined in Claim 8 wherein said broadcast means includes a frequency generator for

10 generating said control signals upon actuation from said microcontroller, each of said control signals having a unique frequency and being associated with one of said switching means and an FM transmitter for broadcasting said control signals continuously throughout said

1.5 location to actuate said switching means to said open position.

10. The system as defined in Claim 9 wherein said reception means includes an FM receiver and a frequency

20. detector for detecting said control signal associated with said switching means.

11. The system as defined in Claim 8 wherein said control means further includes a second reception means

25 for receiving status signals from said switching means and said switching means include a second broadcast means for generating said status signals to inform said control means of the position of said switching means, said control means broadcasting said control signals for

30 a short duration to actuate said switching means between said positions.

12. The system as defined in Claim 1 further

SUBSTITUTESHEET including connection means for receiving the conductors of a telephone or answering machine at said location; switch means responsive to said control means for connecting and disconnecting said conductors to said telephone lines, said control means including start code detection means for maintaining said conductors in communication with said telephone lines until the reception of a start code.

13. The system as defined in Claim 12 wherein said security code detection means is inoperative until reception of said start code.

14. The system as defined in Claim 13 wherein said control means includes a switch interconnecting said control means and said telephone detection means, said control means operating said switch to an open condition if said security code is not received within a pre¬ determined amount of time after reception of said start code.

15. The system as defined in claim 14 wherein said telephone call detection means include a ring detect circuit informing said control means of an incoming telephone call and current detect means for informing said control means if said telephones or answering machine have answered said incoming call.

SUBSTITUTESHEET