Abstract:
A power control module which can be used to automatically open a power circuit for electrically operated devices, particularly battery operated devices, during predetermined periods of non-use. A timer is reset by a motion detector indicating continuing use. The timer controls a transistor switch which closes and opens the power circuit as required. The timing interval can be user-selected e.g., by programming a microprocessor controller. The transition time between conductive and non-conductive states of the transistor can also be controlled to prolong the life of incandescent bulbs or other sensitive load devices.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority to U.S. Provisional Application Ser. No. 60,442,317, filed Jan. 22, 2003, the entire disclosure of which is incorporated by reference herein. 
     This application is also related to my U.S. Pat. No. 6,642,667, the entire disclosure of which is also incorporated by reference herein, and which includes reference to other patents that reflect the current state of the art. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field of the Invention 
     The present invention relates to a control module for battery operated devices, which functions to open the battery circuit after a predetermined period of non-use. A timer including a motion detector is provided to re-close the battery circuit and reset the timer. The device is self-contained and is configurable so that it can easily be accommodated in many existing products without the need for redesign, or with only minimal redesign. The invention can have utility in flashlights, toys, and numerous other battery-operated devices for which power is needed only when the device is actually in use. 
     2. Relevant Art 
     A known problem with battery-powered devices, such as flashlights, toys, etc. is that they are often inadvertently left on after use, resulting in the cost and inconvenience of premature replacement of batteries. To avoid this, some battery-powered devices, include timers as part of the circuitry which shut the devices down, or initiate a standby mode after a predetermined period of non-use. Several such devices are mentioned in my above-referenced patent. There do not, however, appear to be commercially available shut-off devices adaptable to a wide range of products which can simply be purchased off the shelf, and interfaced with an existing product or design. Availability of such devices could reduce design time and cost, and through standardization, reduce component and even assembly cost. A properly designed device of this kind could be incorporated in many existing devices even by the end user, or during manufacture with no redesign in many instances, or with only minimum packaging and/or component layout redesign. A need for such a device clearly exists. 
     Another known problem, particularly in devices such as flashlights, is the need for frequent replacement of bulbs. Incandescent lamps for flashlights are rarely designed for long-life, and indeed, the opposite is usually true. Light output is generally increased at the expense of bulb life. Seemingly, spare bulbs are never at hand when needed, and replacement is often inconvenient in any event. A practical way to increase bulb life without reducing light output which could readily be incorporated in a flashlight would be desirable, but that, too, does not appear to be commercially available. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the present invention to satisfy the above-described needs for a self-contained unit which provides an inactivity shut-off function and optionally, bulb-life enhancement, and which can be inserted in existing products with little or no redesign. 
     An additional object of the invention is to provide a control module which can be used with a variety of existing electrical and electronic devices to enhance utility through availability of programmable functions. 
     A further object of the invention is to provide a self-contained power control module for battery operated devices which can be programed for use in a variety of applications with different operating parameters. 
     A power control module device according to one feature of the invention comprises an electronic circuit board including a timer, a timer reset circuit, a transistor switch and an associated control circuit, and a motion detector, like an accelerometer. These are all mounted on a circuit board which can fit into many existing devices. The transistor is operable to open the battery circuit, thereby turning off a connected load after a predetermined period of non-use such as two minutes, if the device remains motionless. 
     The battery circuit is reactivated if motion of the device triggers the motion detector to reset the timer which then remains on for another two minute interval. The timer can also be reset by turning a main switch off and back on again. If the device is in constant motion, the motion detector is repeatedly reset for successive two minute intervals and the device remains in operation. 
     According to a second feature of the invention, the module is in the form of a thin disc or plate. Different sizes can be provided for use with different type batteries and battery compartment configurations. The module can then be installed in the battery compartment, in line with, or adjacent to the batteries, with the transistor switch in series with the battery circuit. 
     According to a further feature of the invention, the switch control circuit can include a delay timer which provides for controlled turn on and turn off of the transistor switch to enhance the life of a load device such as an incandescent lamp in a flashlight. 
     According to yet a further feature of the invention, an integrated circuit programmable controller can be included to provide selectable inactivity time out intervals, and selective operation of the turn on-turn off delay, and other user-programmable functions. 
     According to another feature of the invention, the module can be used with remotely located motion sensors and also to control mains-powered loads to provide programmable capabilities in devices lacking such features when purchased. 
     Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a plan view of a control module according to one embodiment of the invention designed for use with a standard nine volt battery showing a preferred mechanical arrangement of contacts and circuit elements. 
         FIG. 1B  is a partially cross sectioned schematic view taken along line  1 - 1  in  FIG. 1A . 
         FIG. 2A  is a plan view of a control module according to a second embodiment of the invention designed for insertion between batteries in a battery box in series with the battery electrical circuit showing a preferred mechanical arrangement of contacts and circuit elements. 
         FIG. 2B  is a partially cross sectioned schematic view taken along line  2 - 2  in  FIG. 2A . 
         FIG. 3  is a schematic side elevation drawing of the control module of  FIG. 2  inserted between batteries in a battery compartment. 
         FIG. 4A  is a bottom plan view of a control module according to a third embodiment of the invention similar to that shown in  FIG. 2  but with a terminal clip to provide for attachment to a battery and provide both polarities (+) and (−) of the battery voltage to be available to operate the time-out circuit with a minimum of voltage drop to the system&#39;s series battery circuit. 
         FIG. 4B  is a partially cross sectioned schematic view taken along line  4 - 4  in  FIG. 4A . 
         FIG. 5A  is a schematic type drawing of the control module of  FIG. 4  with the battery attachment and voltage supply clip insert into a typical battery compartment. 
         FIG. 5B  is an enlarged view of a portion of  FIG. 5A . 
         FIG. 6  is a block diagram of the circuitry of an automatic time-out shut-off device with movement sensing reset according to the invention. 
         FIG. 7  is a flow chart showing the operational characteristics of the automatic time-out shut-off device with movement sensing reset. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1A and 1B  show schematically a first embodiment of an automatic shut-off control module, generally denoted at  1 . This is configured for use with a standard nine volt battery. Shut-off device  1  includes a base plate  9  which is preferably a printed circuit board (PCB) fabricated in conventional fashion. On one side  9 A of PCB  9  are mounted a transistor switch  4 , a control unit  5  including a timer, a timer reset circuit, and a driver for transistor  4 , a motion sensor  6 , a female snap connector  2  and a male snap connector  3 . Connectors  2  and  3  are configured for respective attachment to the male (positive) and female (negative) terminals of a nine volt battery (not shown). 
     Mounted on the other side  9 B of PCB  9  are snap terminals  2 A and  3 A, respectively aligned with terminals  2  and  3 . Terminal  2 A is male to correspond to the male positive terminal of the battery, and terminal  3 A is female to correspond to the female negative terminal of the battery. Terminals  3  and  3 A are electrically connected by a conductive sleeve  3 B to provide a direct connection through the circuit board to the negative terminal of the battery. Terminals  2 A and  3 A are intended for connection in conventional fashion to provide operating power for a load device through a main on-off switch (both of which are not shown in the interest of simplicity). 
     As described in more detail below in connection with  FIG. 6 , transistor  4  provides a switched connection between positive terminals  2  and  2 A, which are accordingly connected to the emitter and collector terminals if a junction transistor is employed, or to the source and drain terminals when a MOSFET or the like is employed. 
     Thus, when the main switch is turned on, transistor  4  is switched to its conductive state, and the battery circuit through contacts  2  and  2 A is closed, permitting the load device to operate. As long as the timer in control circuit  5  is repeatedly reset by motion sensor  6  within its timing interval, transistor  4  remains conductive, and the battery circuit remains energized. However, if the timer times out, transistor  4  is switched to its non-conductive state and the battery circuit is opened. Transistor  4  remains non-conducting, and the battery circuit remains open, until motion is again detected, or the main switch for the load device is turned off, then on again. 
     Alternatively, positive terminals  2  and  2 A can be connected-through on the circuit board with the transistor providing a switchable path between negative terminals  3  and  3 A, depending on the type of transistor used and the design of the electronic circuit. 
     An outer skirt  7  formed of any suitable resilient material, may be insert molded onto circuit board  9  to give it orientation for connection to the battery terminals and help hold it in place along with its snap connectors  2  and  3 . 
     Control circuit  5  can be fabricated as an integrated circuit on a custom circuit silicon die (a small chip of silicon with custom circuitry such as a computer chip) for high volume, low cost production. The chip is preferably surface mounted as shown on PCB  9  and then encapsulated with epoxy or the like onto board  9  for moisture and mechanical protection. Depending on the heat dissipation requirements, transistor  4  may be part of chip  5 , or may be separately mounted and encapsulated, as shown. 
     Motion detector  6  for the control module  1  in  FIG. 1  is comprised of a small metal ball  6 A movably enclosed under an arcuate metal conductive cover  6 C and is positioned and configured to make interrupted contact with an arcuate circuit trace  6 B on PCB  9  as movement of device  1  causes motion of the ball. This intermittent contact closure continuously resets the timer in control circuit  5  as described below in connection with  FIG. 6 . 
       FIGS. 2A and 2B  illustrate a second embodiment of the automatic time-out shut-off device, generally denoted at  10 . This is configured to be placed between two series-connected batteries  31  and  32  mounted in a battery compartment  30  such as the barrel of a flashlight or the like, as shown in  FIG. 3 . For simplicity, the load device and the main on-off switch are not illustrated. 
     Control module  10  includes a switching transistor  14 , a control circuit  15 , and a motion sensor  16 , all of which may be respectively the same as or similar to transistor  4 , control circuit  5 , and motion sensor  6  previously described in connection with the embodiment of  FIGS. 1A and 1B . All of these components are mounted on a PCB  19  with the transistor and control circuit encapsulated, also as described above. 
     As will be appreciated, PCB  19  is sized and configured to fit into battery compartment  30  with the overall thickness of device  10  being accommodated by compression of spring  34  at one end of battery compartment  30 . 
     The outside edge of PCB  19  can be encapsulated with a resilient strip  17  made of rubber or the like, with a flexible tab  18  for aiding in removing the batteries from the battery compartment  30  as shown in  FIG. 3 . 
     When device  10  is installed, terminals  12  and  12 A are respectively in contact with terminals  35  and  36  of batteries  31  and  32 . Terminals  12  and  12 A are insulated from each other by circuit board  19 , and thus provide a break in the battery circuit for the load. Closure of the battery circuit is effected by connection of terminals  12  and  12 A in series with the current path of transistor  14 , e.g., with the collector and emitter terminals in the case of a junction transistor, or with the source and drain terminals of a MOSFET or the like, as in the embodiment of  FIGS. 1A and 1B . 
     Also as in the embodiment of  FIGS. 1A and 1B , when the main switch for the load device is turned on, transistor  14  is switched to its conductive state, and the battery circuit is completed. As long as the timer in control circuit  15  is repeatedly reset by motion sensor  16  within its timing interval, transistor  14  remains conductive, and the battery circuit remains energized. However, if the timer times out, transistor  14  is switched to its non-conductive state and the battery circuit is opened. Transistor  14  remains non-conducting, and the battery circuit remains open, until motion is again detected, or the main switch for the load device is turned off, then on again. 
       FIGS. 4A and 4B  illustrate a power control module, generally denoted at  40 , which is similar to device  10  of  FIGS. 2A and 2B , but also includes a spring clip connector  50  preferably formed of an electrically conductive material, and having first and second circular end plates  51  and  52 , and a connecting arm  41 . Control module  40  is attached to end plate  52  in any suitable manner, as discussed more fully below. Spring clip connector  50  is configured to snap onto a cylindrical battery  54  installed with one or more additional batteries  54 A in a battery compartment  55 , as illustrated in  FIG. 5 . When spring clip  50  is attached to battery  54 , a contact area  41 A on end plate  51  is connected to the negative battery pole  56 , and a contact  42  on module  40  is connected to positive battery pole  60 . 
     Control module  40  includes a switching transistor  44 , a control chip  45  including a timer and timer reset circuit, and a motion detector  46 , all mounted as previously described on a PCB  49 . A second terminal  42 A on the side of PCB  49  opposite to terminal  42  permits connection of the batteries and the control module in the battery circuit for the load device (not shown). For this purpose, end plate  52  includes a circular central aperture  61  through which terminal  42 A is accessible. As will be appreciated, module  40  is secured to the margin of aperture  62 . This may be done by a suitable adhesive, or in the process of encapsulating transistor  44  and control chip  45 . 
     Transistor  44  and control chip  45  function in the same way as transistor  24  and control chip  25  in the embodiment of  FIGS. 2A and 2B  to connect terminals  42  and  42 A when the battery circuit is intended to be energized, and to break the connection between terminals  42  and  42 A when the battery circuit is intended to be de-energized. 
     With the construction of  FIGS. 4A and 4B , electrical connections to both poles  58  and  60  of battery  54  are available at module  40 . This permits operation of the control device with a minimum series circuit voltage drop. 
       FIG. 6  shows a basic block diagram schematic of the electrical control circuitry of the automatic time-out device with its flow-charted operational characteristics shown in  FIG. 7 . 
     In  FIG. 6 , a generalized module  70  is shown connected between battery input terminals  62  and  62 A in a series circuit comprised of a battery  72 , a load  74  and a main on-off switch  76 . Connection between terminals  62  and  62 A is through the current path of a transistor switch  65 . 
     Control module  70  is also comprised of a control circuit  65 A which drives transistor  65  into and out of conduction as required, a timer circuit  64  and a timer reset circuit  64 A, and a motion detector  66 . Control circuit  65 A and timer  64  respond to an off-on transition of switch  76  to start the timing interval and to place transistor  65  in the fully conductive state. This completes the battery circuit through terminals  62  and  62 A, and energizes load  74 . Timer reset circuit  64 A, and motion detector  66  cooperate to reset timer  64  whenever motion is detected. 
     If the timing interval ends without motion being detected, timer circuit operates control circuit  65 A to place transistor  65  in its non-conductive state. This opens the battery circuit and energizes load  74 . A long as switch  76  remains closed, motion sensed by detector  66  will reset timer  64  and transistor  65  will again be placed in its conductive state to re-energize the battery circuit. A similar result is obtained if main switch  76  is opened and re-closed. 
     No exact electrical circuit implementation for module  70  is disclosed, as many circuits capable of performing the functions described will be readily apparent to those skilled in the art. 
     In this connection, it should be recognized that the required functions may readily be provided by a programmed microprocessor implementation. That has the advantage of facilitating programmed setting of a desired time out interval, and also selectable provision of controlled turn on and turn off of transistor  65 . 
     It should also be recognized that the life of certain devices such an incandescent bulbs or sensitive electronic devices can be significantly increased if they are not subjected to the shock of large current changes when they are energized and de-energized. This can be achieved according to the present invention by incorporating into transistor control circuit  65 A a delay feature providing a staged transition, e.g., over a one or two second interval, between the conductive and non-conductive states of transistor  65 . Various ways of doing this, both in a circuit implementation of control circuit  65 , or as part of a microprocessor implementation, will be readily apparent to those skilled in the art. 
     The resulting soft turn on and turn off current to the incandescent filament, etc., can greatly enhance the life of such a device. Additionally, either or both the automatic turn off and the controlled transition functions can be made selectable, especially by preprogramming in a microprocessor implementation, while use of switches or the like to provide this function (or time-out interval selection) might prohibitively increase the size of the module. 
     The programmable microprocessor implementation with a suitable interface such as a PC or dedicated input device can also allow use of the control module for programming customized on/off control of a variety of existing battery operated devices, or even mains-operated devices. For the latter purpose, module could be incorporated in a unit having a plug for direct connection to the wiring, and a receptacle for providing power to the controlled device. Thus, on/off control desired for particular time of day, for example, for home lighting, heating or an oven could be provided. Additionally with suitable motion detectors (including, if desired, remote detectors), the device can readily be used as an intrusion detector for homes to provide an alarm and turn on lights as desired. Other applications will also be readily apparent to those skilled in the art. 
     The motion detector can be a number of different types known in the art such as accelerometers, mechanical vibration sensors vibrating wires, etc., as well as various non-contact sensors for detecting motion in volumes of space such as rooms. For example, a drop of mercury could replace the ball to make and break contact with the traces on the circuit board. 
     Therefore, while the present invention has been described a relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is therefore intended that the present invention not be limited by the specific disclosures herein but that it be afforded the full scope defined by the appended claims.