Abstract:
An electrical circuit is disclosed which provides the capability of starting up an unattended computer or similar device either from a remote location or at a predetermined date and time. The circuit includes an electrical energy storage device which, when a telephone ring signal is detected, initiates start-up of the computer. Alternatively, an interrupt from a date timer may initiate start-up of the computer using the energy storage device. Once start-up of the computer is initiated, its power supply provides the necessary voltage which, in conjunction with a latching transistor, maintains the electrical circuit providing AC power to the power supply and computer and recharges the electrical energy storage device. Finally, an electrical signal to power-down the computer may be initiated either remotely or through software instruction.

Description:
FIELD OF THE INVENTION 
     This invention pertains to computers and similar equipment and more particularly to power-up of such devices while they are unattended. 
     BACKGROUND OF THE INVENTION 
     Computers and similar equipment have had the capability for a number of years to communicate via telephone lines through the use of modems and telephones. The general practice has been for the user to power-up his own computer and then, by means of a telephone, &#34;call up&#34; a computer operating at a remote location. If a user desired to receive messages on his computer, he was obliged to leave the computer powered up during the time in which he wished to receive data transmissions. Without leaving the computer on, the user gave up the ability to send and receive those transmissions. 
     The practice of leaving one&#39;s telecomputing equipment powered up while unattended has many disadvantages. The computer which is powered up and left unattended represents an increased safety hazard which can risk damage to either the computer itself or its surrounding environment, or both. There is continuous power consumption as well as equipment damage susceptibility due to power failures. Further, numerous extended periods of operation will decrease the reliability of the computer and its useful life will be significantly shortened. 
     SUMMARY OF THE INVENTION 
     Applicant&#39;s invention overcomes the above-mentioned disadvantages by providing a method and apparatus for powering up a computer from a remote location. The computer can be turned off while unattended and, when it is desired that the computer send or receive data, it can be powered up from a remote location or at a predetermined time, send or receive data, and then power down automatically. 
     The preferred embodiment of the apparatus comprises a telephone ring detector which is connected to the incoming telephone line to detect the ringing signal. A switch in the power-up circuitry is closed when the detector detects the telephone ringing signal. Upon the closing of the switch and completion of the power-up circuit, an energy storage device causes a power-up signal to be sent through the computer power supply and power-up of the computer is initiated. After the computer is powered up and the telephone signal is cleared, the computer sustains itself by means of its power supply. 
     The remote power-up circuitry also includes the capability of detecting an interrupt signal generated by the date timer contained within the computer and, in response thereto, a switch is closed which once again completes the power-up circuit. The computer is powered up in the above-described manner. The use of the date timer enables the user to preprogram the date and time at which the computer will be powered up. 
     It is therefore an object of the present invention to provide a method and apparatus for causing a computer to be powered up either from a remote location or at a predetermined day and time, thus eliminating the need for long-term continuous operation of the computer. 
     Other objects and advantages will become obvious to those skilled in the art upon review of the detailed description in conjunction with the drawing and appended claims. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram showing the primary components of one embodiment of the apparatus of the present invention. 
     FIG. 2 is a simplified schematic of one circuit of the present invention showing the main components thereof. 
     FIG. 3 is a schematic showing a telephone ring detection circuit and its associated opto-coupler. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a block diagram showing the primary components of one embodiment of the present invention and the direction of current flow through the circuit. Very broadly, the apparatus comprises an energy storage device 6, a date/time circuit 7, a telephone ring detection system 8, and a latch-in circuit 9. The computer power supply 21 generally exists in the computer, although external supplies may be used. 
     FIG. 2 is a simplified schematic of one embodiment of the present invention. The remote start-up circuitry generally comprises capacitor 11, opto-coupled triac 12, opto-coupler 13, telephone ring detector 14, transistor 15, and latching transistor 16. Also shown in FIG. 2 are certain existing components of the computer utilizing the remote start-up capability. Among those existing components are the power supply 21, date timer 22, and computer component 23. 
     Opto-coupled triac 12 is preferably installed within the existing computer power supply 21. The anode terminal of the primary of triac 12 is connected to capacitor 11 by way of a 100 ohm resistor 18. The connections to the cathode of the primary of triac 12 will be more fully described below. The secondary of opto-coupled triac 12 is connected in the stand-by power circuit of power supply 21. 
     Capacitor 11 is a 1.0 farad capacitor, the positive terminal of which is connected to the anode of triac 12 through resistor 18 as described above. The negative terminal of capacitor 11 is connected to electrical ground within the computer. Also connected to the positive terminal of capacitor 11 is the cathode terminal of diode 17. The anode of diode 17 is connected to a +5-volt DC output of power supply 21. 
     The cathode of the primary of opto-coupled triac 12 is connected to opto-coupler 13, transistor 15, and latching transistor 16. Transistor 15 is a 2N2907, or equivalent, transistor with its emitter connected to the cathode of triac 12. The collector of transistor 15 is connected to electrical ground within the computer. The base terminal of transistor 15 is connected to the &#34;interrupt&#34; terminal of the existing date timer 22 within the computer. The interrupt timer is preferably a CMOS device which stores and updates the time and date once initiated by the operator. Such a timer is known in the art. 
     Transistor 16 is a 2N2102, or equivalent, transistor whose collector is electrically connected to the cathode of triac 12. The emitter of transistor 16 is connected to electrical ground and the base terminal is connected to existing computer component 23. 
     Component 23 generates an electrical signal whenever the computer is operational, or until receiving a computer instruction to cease, and this signal, in the preferred embodiment of the present invention, is applied to the base terminal of transistor 16. As a result, during operation of the computer, transistor 16 is in a conducting state, providing an electrical path for flow of current through triac 12. 
     Opto-coupler 13 is an electrical isolating device which generally comprises a diode 26 and a transistor, or transistor pair, 27. The collector of transistor 27 is connected to the cathode of opto-coupled triac 12, while the emitter of transistor 27 is connected to electrical ground. The base terminal of transistor 27 is not used in this application of opto-coupler 13. Although a cascading transistor pair is shown in FIG. 2, a single transistor or similar device will perform the required function. 
     Electrically isolated from transistor 27 is diode 26. Diode 26 is connected across the output terminals of telephone ring detector 14 by means of RC network 20. An incoming telephone line 33 is connected to the input of ring detector 14 by means of RC network 19. Networks 19 and 20 will be more fully explained below. 
     FIG. 3 illustrates telephone ring detector 14, RC networks 19 and 20, and opto-coupler 13. Telephone ring detectors are well known in the art and a variety of different detectors will function satisfactorily for purposes of the present invention. It should be remembered that this is only one embodiment of a component of the present invention. 
     As shown in FIG. 3, ring detector 14 has four input terminals and four output terminals. The four input terminals are connected to the incoming telephone line 33 by way of a series of resistors and capacitors and a diode bridge 28. The series of resistors and capacitors shown connected to terminals 1 through 4 of ring detector 14 comprise RC network 19. The series of resistors and capacitors connected to terminals 5 through 8 of ring detector 14 comprise RC network 20. RC networks 19 and 20 help insure that erroneous detection of ringing signals is minimized and numerous configurations of such networks may be substituted for those shown to perform a like function. 
     The embodiment illustrated in FIG. 3 may be connected to either of two telephone ring circuits 34 or 35 by way of diode bridge 28. 
     The operation of the remote power-up circuit may be understood by reference to FIG. 2 and is substantially as follows: 
     When the computer system is powered up by moving the power switch 31 to the &#34;on&#34; position, computer power supply 21 provides DC power for operation of the computer. A +5-volt output from power supply 21 charges capacitor 11 through diode 17 to a voltage of approximately 4.4 volts. When the system is powered down, capacitor 11 will retain its stored energy and, after approximately 90 days, the voltage will still be approximately 2.0 volts, sufficient to initiate start-up of the computer. Under ideal conditions, capacitor 11 will retain sufficient energy to initiate start-up for as long as 180 days. 
     Once capacitor 11 has been charged, the computer is powered down and switch 31 is placed in the &#34;stand-by&#34; position. In this position, the computer remains powered down as the secondary of opto-coupled triac 12 acts as an &#34;open&#34; switch, preventing application of external power to the computer power supply 21. 
     With the computer switch 31 in the &#34;stand-by&#34; position, two independent conditions can initiate start-up of the power supply using the remote power-up circuitry. The computer will be powered up when an electrical ringing signal is detected on the telephone circuit 33. The computer will also be powered up if an interrupt is issued from the existing date timer 22 in the computer. 
     As explained above, telephone ring detector 14 is connected to an incoming telephone line 33. When an electrical signal appears on the telephone line 33 denoting a ringing signal, ring detector 14 detects said signal on its input terminals 1 through 4. In response to that detected signal, detector 14 generates an electrical signal at its output terminals 5 through 8. A current is caused to flow through diode 26 of opto-coupler 13. 
     The flow of current through diode 26 causes transistor 27 of opto-coupler 13 to begin to conduct. Opto-coupler 13 functions much like an isolating relay in that a current flowing through its primary component, diode 26, causes its secondary component, transistor 27, to conduct. Transistor 27 therefore functions as a switch which closes upon application of electrical current to, or energization of, diode 26. 
     As transistor 27 begins to conduct, an electrical circuit is completed from capacitor 11, through resistor 18 and optocoupled triac 12, through transistor 27. The electrical energy stored in capacitor 11 begins to discharge causing a flow of current through the primary component of opto-coupled triac 12. This flow of current through the primary component of triac 12 causes the secondary component of triac 12 to begin to conduct. As in the case of opto-coupler 13, opto-coupled triac 12 acts as a relay and the secondary component of triac 12 functions as a switch, closing upon application of electrical power to the primary and completing the power circuit in the computer power supply 21. 
     As the secondary of opto-coupled triac 12 begins to conduct, external AC power is applied to the power supply 21 through the stand-by power circuit. Power supply 21 begins supplying DC power necessary to operate the computer. The +5-volt DC supply connected to diode 17 is therefore available, replacing the need for additional discharge of capacitor 11 through the primary of opto-coupled triac 12. In addition, the +5-volt DC source operates to recharge capacitor 11 to its 4.4 volt value. 
     As start-up of the computer is initiated, an electrical latch-in signal is generated via existing computer component 23 to the base terminal of latch-in transistor 16. Application of the latch-in signal to transistor 16 causes the collector and emitter of transistor 16 to begin to conduct. As a result, latch-in transistor 16 performs essentially the same function as transistor 27 of opto-coupler 13, providing an alternate switch for completion of the power-up circuit. 
     Substantially less than one second of time is required to initiate start-up of the power supply, provide the +5-volt DC supply, and apply the latch-in signal to transistor 16. The telephone ringing signal lasts for more than one second. Consequently, in the space of one ringing signal, the computer is caused to begin power-up and latch itself in. When the ringing signal is cleared, opto-coupler 13 drops out and transistor 27 ceases to conduct. However, by that time, latch-in transistor 16 has begun to conduct and opto-coupled triac 12 is latched in. 
     The second mode of powering up the unattended computer involves the generation of an interrupt signal by the date timer 22 located in the computer. The date timer 22 can be preprogrammed to generate the interrupt at a preselected time. At the preselected time, the interrupt is generated and the signal is applied to the base terminal of transistor 15. Application of the signal to the base of transistor 15 causes the collector and emitter to begin to conduct. Transistor 15 acts as a switch which closes in response to the interrupt signal and completes the remote power-up circuit similar to the function of transistor 27 of opto-coupler 13. 
     Similar to the power-up described above, as transistor 15 begins to conduct, capacitor 11 begins to discharge through opto-coupled triac 12 and transistor 15. The flow of current through the primary of triac 12 causes the secondary of triac 12 to begin to conduct, causing power to be applied to the computer power supply 21. 
     As before, initiation of the start-up causes the +5-volt DC source to become available and the latch-in signal to be generated by way of the existing computer component 23 and applied to the base terminal of latch-in transistor 16. As before, the opto-coupled triac 12 is latched in. 
     Once the system has been remotely powered up, the remote user may send data to or receive data from the computer by means of conventional modems. This type of data transmission is well known in the art. When data transmission is complete, the system may be powered down by causing the computer to cease the generation of the latch-in signal. This may be performed by an instruction initiated in a computer program or initiated in response to an instruction received from a remote source. 
     When the latch-in signal is interrupted and is no longer applied to the base terminal of latch-in transistor 16, transistor 16 ceases to conduct, thus opening the remote power-up circuit. Because transistors 15 and 27 are also no longer conducting, current ceases to flow through the primary of opto-coupled triac 12. Triac 12 &#34;drops out&#34; and its secondary ceases to conduct. This &#34;opening of the switch&#34; interrupts the application of AC power to the computer power supply 21 and the computer is caused to power-down. 
     As stated earlier, while the computer is operating, capacitor 11 is being recharged through diode 17 by the +5-volt DC supply to its storage value of 4.4 volts. When the computer has been remotely powered down, capacitor 11 will once again retain its charge for an extended period of time, ready to initiate another start-up upon receipt of a telephone ring signal or an interrupt from the computer date timer 22. 
     Although the telephone ring detection system described above demonstrates the preferred mechanism and method for detection of a remotely generated power-up signal, various other remote signals may be used, resulting in variations in the detection scheme. For example, a remotely generated signal may be transmitted via microwave or other communication system and the detection scheme may be altered to more nearly resemble the detection scheme utilizing transistor 15 described above. In other words, the detection of a remotely generated signal does not necessitate the use of an isolating device, such as opto-coupler 13; rather, the remote signal may be directly applied to the base terminal of a transistor, as in transistor 15, causing it to conduct electrical current through its collector and emitter. Devices other than the semiconductor devices described herein could also be used to perform similar functions. 
     Further, energy storage device 11, although shown to be a capacitor in the preferred embodiment, could be a battery, rechargeable or otherwise, or could even be a DC supply maintained by an available AC source, such as at switch 31. The energy source 11 need not be a passive storage device but, rather, may be an active source. 
     As can be appreciated by one skilled in the art, the above detailed description describes only one embodiment of the present invention. Various components may be replaced by other electrical, electromechanical, or semiconductor devices to accomplish the same result, particularly in view of the interchangeable nature of such devices and their functions in the present invention. Variations and modifications of the invention will become obvious from the drawings and specification. Accordingly, applicant&#39;s invention should be limited only by the scope of the appended claims.