Abstract: A diagnosis assistance apparatus, a diagnosis assistance method, a diagnosis assistance program, and a bodily information measurement apparatus, assist diagnosis by outputting information that is useful for the diagnosis. A bodily information measurement apparatus includes a data acquisition unit that acquires data for analysis in which bodily information measured from a measurement subject and position information of the measurement subject at the time of measuring the bodily information are associated; an index generation unit that, based on bodily information associated with position information that is included in the data and belongs to multiple pieces of pre-registered location information, generates numerical value indices for determining a bodily state of the measurement subject with respect to the respective pieces of location information; and an output unit that performs output based on the numerical value indices generated for the multiple pieces of location information.

Abstract: A heating blanket system comprises a blanket, one or more heating wires embedded within the blanket, a control switch embedded in the blanket, the control switch being configured to allow a user to adjust a temperature setting of the blanket, and an external control module detachably connectable to the control switch and the one or more heating wires, the external control module configured to receive the temperature setting from the control switch and configured to control current flow through the one or more heating wires based on the temperature setting, the external control module being external to the blanket.

Abstract: A phototherapy device comprising an outer garment wrap and a lamp assembly. The outer garment wrap has an inner surface. The lamp assembly has a base layer and a frame defining a plurality of inner chambers. A LED lamp assembly is positioned within each of the plurality of inner chambers. The lamp assembly is positioned on the inner surface of the outer garment wrap. A protective lamp envelope for receipt of the lamp assembly and attachment thereof to the outer garment wrap is likewise disclosed.

Abstract: The method for assembling a microelectronic chip device (101) in a fabric (104) comprises the following steps: providing a microelectronic chip device (101) comprising a base (102) and a protruding element (103) rising from a face of the base (102), said protruding element (103) comprising a free end opposite the base (102); inserting into the fabric (104) the chip device (101) by the free end of the protruding element; deforming the protruding element (105) at its free end so as to ensure the securing of the chip device (101) with the fabric (104) by forming a crimping bead (106).

Abstract: A strip LED comprises an LED chip, an embedded resistor, a magnet, a magnetic material, a strip encapsulation bracket and a power source. An installation bracket for the embedded resistor and the LED chip is provided between connection brackets. The connection bracket metal strips a and b and metal strips c and d are either a single narrow and thin metal strip or a plurality of thin metal wire structures. The magnet is fixed at one end of a wire, and another end of the wire is connected to the power source.

Abstract: The present invention provides a stretch-resistant light-emitting or heat-emitting structure. The wirelessly-chargeable stretch-resistant light-emitting structure includes a woven member, conductive twisted cables, a light-emitting element, and a receiver circuit. The woven member is mounted to the article. Each conductive twisted cable includes a stretch-resistant wire and a electrically conductive wire twisted together. The conductive twisted cables are woven in the woven member. The light-emitting element, which is arranged inside the woven member, includes a light emission section and two conductive pins. The conductive pins are respectively and electrically connected to the electrically conductive wires of the conductive twisted cables.

Abstract: Computer-aided design and manufacture software and hardware automate garment and fashion definition and production. Configurable garment includes ornamental element, pattern display, and personal identifier and wireless sensor electronics.

Abstract: Disclosed is a digital garment using embroidery technology. In the digital garment, a digital embroidery pattern is formed on a common garment to provide a communication path, an antenna pattern, etc. The digital garment comprises a garment made of a textile and having one side and the other side opposite to each other, a digital embroidery pattern formed along the inner or outer surface of the garment using embroidery technology to provide a communication path to the garment, a sensor attached to the garment and electrically connected to the digital embroidery pattern to convert physical signals to electrical signals, an arithmetic unit attached to the garment and electrically connected to the digital embroidery pattern to process the electrical signals inputted from the sensor, and a communication module attached to the garment and electrically connected to the digital embroidery pattern to perform wireless communication.

Abstract: An apparatus is configured with one or more sensors arranged to detect a first shape-related parameter, one or more control elements arranged to provide a force, and circuitry operably connected to the one or more sensors and the one or more control elements to determine the force provided to the one or more control elements.

Abstract: The present invention relates to an electrically conductive textile yarn for production of protective garments, comprising a first element which is made electrically conductive by means of a layer of silver, and a second element which is different from the said first element, and is provided with good resistance to fire; the first element can be in the form of filaments or fibers. The present invention also relates to a garment produced by means of a yarn of this type and to a method for production of the yarn itself.

Abstract: A personal protective suit including a sealed shell equipped with connection device intended to be connected to one same pressurized air source, air distribution device having an air intake connected to the connection device, and at least one first and one second air outlet, respectively intended to supply device for delivering air to the wearer and device for ventilating the suit, wherein the air distribution device includes a valve designed to reduce the air flow rate of the second air outlet when the air pressure at the air intake is below a determined value, while maintaining the supply of air to the wearer.

Abstract: The invention is a garment with an integrated earphone, headset, and wire. The wire allows an audio signal to travel from an electronic device at one end of the wire to the earphone or earphones, and/or a microphone at the other end of the wire. The wire, or wires, is preferably permanently sewn into the seams of the garment. The earphone may be retractable and/or kept in a small pocket near the collar of the garment to limit the movement of the earphone when it is not being actively used. The integrated earphone and microphone are preferably machine washable and dryable along with the garment with which they are integrated.

Abstract: A fashion apparel accessory, such as a garment, having one or more concealed light sources positioned so as to illuminate the skin of the wearer, as opposed to focusing attention on the light sources themselves. A particular embodiment includes concealed light sources proximate to a low-cut neckline of a female's garment, such as brassiere, shirt, or item of lingerie, with the light sources being oriented so as direct illumination across the wearer's chest area in an alluring way, potentially offering multiple color, intensity, direction/control options as well as multiple deployment techniques/devices. A portable power supply is integrated with the garment or accessory and electrically connected to the light sources.

Abstract: Fibers, such as textile fibers, having electrical components deposited thereon. More particularly, one or more electrical components are formed directly onto the surface of at least one fiber. The fiber having the electrical component formed thereon may then be interlaced with other fibers to form a larger piece of fabric, which can be employed to produce an article of clothing. A group of transistors and piezoelectric components forming an accelerometer may be woven onto one or more natural or synthetic fibers. The fibers may then be employed as the warp, weft, or both, of a woven piece of fabric, or used to form a knitted piece of fabric. The fabric piece can then be cut and sewn to form a wearable item, such as a shirt, a pair of pants, a hat, or the upper piece of a shoe that includes the accelerometer.

Abstract: Headgear for mounting a headlight on a surgeon's head includes a headband and a stabilizer. The headband encircles the wearer's head and the stabilizer is connectable to a rear section of the headband for engaging and cradling a substantial portion of at least a lower back region of a wearer's head when the headgear is worn by the wearer. The stabilizer includes a peripheral extending portion extending beneath the headband on opposite sides of the wearer's head corresponding to a location of a lower portion of an occipital bone of the wearer's head and a peripheral portion extending above the headband on opposite sides of the wearer's head corresponding to a location of a top of the occipital bone. The headgear can also include a connection element for removably connecting the stabilizer to the headband so that the headgear can be worn with or without the stabilizer.

Abstract: Presented is a variety of products and apparatuses employing a conductive nonwoven web. Products and apparatuses include an RFID system, a radiofrequency shielding system, a flexible electronic circuit component, a heating element, an antenna, an electromagnetic energy shield, a membrane switch, a keypad, and a packaging system. In one embodiment, the conductive nonwoven web contains conductive carbon fibers in combination with pulp fibers and/or synthetic fibers. Electric pathways are formed into the conductive material using ultrasonic energy. The electric pathways can be used to produce various electronic devices.

Abstract: An apparatus is configured with one or more sensors arranged to detect a first shape-related parameter, one or more control elements arranged to provide a force, and circuitry operably connected to the one or more sensors and the one or more control elements to determine the force provided to the one or more control elements.

Abstract: The invention provides a functional stretch laminate composite puckered fabric which is robust, laundry-durable and adaptable for securing about any three dimensional body, and a method for forming such puckered fabric. The functional stretch laminate fabric is provided with at least one functional element which can conduct electricity, conduct light, provide electromagnetic fields or provide shielding from electromagnetic fields. In addition, at least one via is provided in the functional stretch laminate allowing the functional element to extend or loop outwardly from the at least one via when the laminate is in a relaxed or unstretched state. Generally, the functional stretch laminate fabric is sufficiently robust for incorporation into garments and for applications in so-called wearable electronics.

Abstract: A neckerchief slide has one form that has a rigid body with a flat body portion and three spaced, rigid loops that project outwardly and rearwardly from the body portion, and a flashlight integrated into the body portion. The loops define apertures for the ends of a neckerchief. One end of the neckerchief goes through one aperture, the other end goes through another aperture, and both ends go behind the body portion and through the third aperture. The bulb of the flashlight points down during normal wear, and is easily pointed forward without removing the slide from the neckerchief or the flashlight from the slide. A second form of a neckerchief slide omits the flashlight. Indicia is displayed on the front of the neckerchief slide.

Abstract: An ear warming article that can be comprised of a C-shaped resilient band, an outer sleeve and a speaker or other electronic device is described. The outer sleeve is dimensioned to contain the resilient band, and includes two insulating, ear-receiving portions as well as a first opening through which the resilient band can be inserted or removed to yield an assembled or disassembled article, respectively. In a preferred embodiment, the article includes an electronic device having one or more speakers located at the ends of the resilient band; additional openings in the outer sleeve may exist for any control functionality associated with the electronic device(s). The outer sleeve can be comprised of a washable fabric material, particularly suitable as a means for interchangeable advertising (team logo, branding, etc.). In other embodiments, the ear warming article includes additional advertising and/or securing features.

Abstract: A digital garment and a fabrication method thereof are provided. The digital garment is fabricated using a knitting technique. The digital garment comprises a plurality of knitting yarns forming loops at regular intervals and interwoven through the loops, and one or more conductive digital yarns tied to the loops of the knitting yarns to form high-speed information communication circuits. The knitting yarns and the digital yarns are knitted together into a garment. During knitting, the digital yarns are used to form high-speed information communication circuits in a rapid and economical manner.

Abstract: Composite foams or leather materials (synthetic or natural) have electrical components deposited thereon. More particularly, one or more electrical components are formed directly onto the surface of the composite foam or the leather material. A group of transistors and piezoelectric components forming an accelerometer may be formed onto a surface of a composite foam or a leather material and incorporated into an article of wear.

Abstract: Fibers, such as textile fibers, having electrical components deposited thereon. More particularly, one or more electrical components are formed directly onto the surface of at least one fiber. The fiber having the electrical component formed thereon may then be interlaced with other fibers to form a larger piece of fabric, which can be employed to produce an article of clothing. A group of transistors and piezoelectric components forming an accelerometer may be woven onto one or more natural or synthetic fibers. The fibers may then be employed as the warp, weft, or both, of a woven piece of fabric, or used to form a knitted piece of fabric. The fabric piece can then be cut and sewn to form a wearable item, such as a shirt, a pair of pants, a hat, or the upper piece of a shoe that includes the accelerometer.

Abstract: Resistance garments include for example a first cuff and a second cuff that circumscribe a portion of a wearer's body; an adjustment device fixedly attached to the first cuff; and a resistive element connecting the first cuff and the second cuff, and coupling with the adjustment device. An active material includes a backing fabric and one or more length-adjusting devices, that each include a first filament and a second filament that are interwoven with the backing fabric and substantially parallel with one another, and one or more motors. Each of the motors drives first and second spooling elements that alternatively reel in or reel out portions of the first and second filaments, respectively. The reeling in or out thereby adjusts (a) a length of the filaments, (b) a length of the length-adjusting device corresponding to the at least one motor, and (c) a length of the active material.

Abstract: An article of clothing with an on-demand power supply for electrical devices is provided. The power supply includes stiff planar fuel cell devices that are distributed in a plane. The number of fuel cells is dependent on the power requirements for the electrical devices. The planar stiff fuel cells are flexibly interconnected in the plane by a flexible interconnection, which allows the fuel cells to move with respect to each other out of the plane. This further allows the power supply to be nicely integrated in an article of clothing and minimizes negative impact to a body region or to the article of clothing. The electrical and fuel connections between the fuel cells are integrated with the flexible interconnection. To further integrate and increase ease of operation a control system is included to control the on-demand power supply or control power levels for the electrical device.

Abstract: An apparatus is configured with one or more sensors arranged to detect a first shape-related parameter, one or more control elements arranged to provide a force, and circuitry operably connected to the one or more sensors and the one or more control elements to determine the force provided to the one or more control elements.

Abstract: A ground contact switch system comprises a first object configured to contact a ground surface during a stride, and one or more switches coupled to the first object. An inertial measurement unit can be coupled to the first object. The one or more switches are configured to detect when the first object is at a stationary portion of the stride. The one or more switches can also be configured to send a signal to activate an error correction scheme for the inertial measurement unit.

Abstract: A solid-state laser emitting material for use in conjunction with a light source includes a polymer matrix functioning as host materials, containing laser dye of rhodamine 590 or rhodamine 610 as gain materials and nano-submicron particles as scatters therein. The lowest lasing threshold of the laser emitting material is approximately 5 mJ/cm2 for 585 nm emission and 2 mJ/cm2 for 630 nm emission.

Abstract: A fashion apparel accessory, such as a garment, having one or more concealed light sources positioned so as to illuminate the skin of the wearer, as opposed to focusing attention on the light sources themselves. A particular embodiment includes concealed light sources proximate to a low-cut neckline of a female's garment, such as brassiere, shirt, or item of lingerie, with the light sources being oriented so as direct illumination across the wearer's chest area in an alluring way, potentially offering multiple color, intensity, direction/control options as well as multiple deployment techniques/devices. A portable power supply is integrated with the garment or accessory and electrically connected to the light sources.

Abstract: Fibers, such as textile fibers, having electrical components deposited thereon. More particularly, one or more electrical components are formed directly onto the surface of at least one fiber. The fiber having the electrical component formed thereon may then be interlaced with other fibers to form a larger piece of fabric, which can be employed to produce an article of clothing. A group of transistors and piezoelectric components forming an accelerometer may be woven onto one or more natural or synthetic fibers. The fibers may then be employed as the warp, weft, or both, of a woven piece of fabric, or used to form a knitted piece of fabric. The fabric piece can then be cut and sewn to form a wearable item, such as a shirt, a pair of pants, a hat, or the upper piece of a shoe that includes the accelerometer.

Abstract: Fibers, such as textile fibers, having electrical components deposited thereon. More particularly, one or more electrical components are formed directly onto the surface of at least one fiber. The fiber having the electrical component formed thereon may then be interlaced with other fibers for form a larger piece of fabric, which can be employed to produce an article of clothing. A group of transistors and piezoelectric components forming an accelerometer may be woven onto one or more natural or synthetic fibers. The fibers may then be employed as the warp, weft, or both, of a woven piece of fabric, or used to form a knitted piece of fabric. The fabric piece can then be cut and sewn to form a wearable item, such as a shirt, a pair of pants, a hat, or the upper piece of a shoe that includes the accelerometer.

Abstract: A safety suit has an interior space that is well air conditioned while the weight to be carried along by the user of the safety suit is reduced to a minimum. A heat exchanger surface (5), which is provided with a porous material (17) towards the outside for evaporating liquid, is provided at the safety suit jacket (3).

Abstract: Self-healing electrical garments and self-healing electrical conductors and components for use in electrical garments are provided. A communication medium of various forms is integrated into a garment seam that is used to join two or more portions of a garment. The communication media can be used to provide electrical or other electromagnetic connection for coupling among a plurality of electrical devices associated with the garment. The self-healing electrical conductor may be used as part of a garment portion or may be used as a joining fiber in a variety of techniques to join garment portions together. The self-healing electrical conductor comprises an electrical conductor, a conductive polymer immediately surrounding or adjacent to the electrical conductor, an insulator enclosing the electrical conductor and the conductive polymer.

Abstract: Disclosed is a garment (102) made of a particular type of material, the garment can include a garment appendage (104, 108, 110, 112) and a sensor (114, 116) coupled to the garment appendage with the sensor configured to detect activation of the garment appendage. The garment can further include a controller (126) coupled to the sensor, with the controller configured to control a function of an electronic device based on activation of the garment appendage when sensed by the sensor. Also disclosed is a method of a garment as described above, the method including activating the garment appendage so that the sensor detects the activation, and processing a signal from the sensor by the controller to that the controller controls a function of the electronic device.

Abstract: A multi-zone blanket includes a body including first heat zones juxtaposed side-by-side and symmetrically aligned within a body cavity. A first primary heating element passes through each of the first heat zones. A first external controller has an AC/DC transformer electrically coupled thereto. The first controller is electrically coupled and removably attached to the first primary heating element. The transformer is removably coupled to an external power supply source which provides a high voltage input to the transformer. The transformer converts the high voltage input to a low voltage input. The first controller includes a mechanism for providing output control signals to the first heat zones such that each first heat zone can simultaneously and independently generate a selected quantity of heat.

Abstract: The present invention provides a fabric display using the action of electrostatic charges to manipulate visual displays. The fabric display comprises areas of furry fabrics (16) that can serve as visual effects or display of information and can be usable in a wearable garment, furniture, or other suitable locations where it can be incorporated to close a circuit. Through activation by the user, the surface of furry fabrics (16) is electrostatically charged causing the furs to repel from the surface and each other in a substantially vertical orientation with portions of the furs extending cut of the surface, thus revealing the color of the fabric surface.

Abstract: A fabric for use with a system for monitoring prescribed body functions comprising an elastic fabric, adapted to be carried by a torso, which is stretchable in its longitudinal direction so as to expand and contract in response to body movement and size. The carrier includes at least one conductive and inelastic yarn arranged longitudinally of and located between upper and lower surfaces. The conductive yarn is arranged in sinusoidal configurations longitudinally of the fabric. The conductive yarn breaks through one of the outer surfaces at a selected breakout along the length of the fabric. The conductive yarn is cut to present at least one exposed end above the one outer surface. A monitoring unit, which includes a connector and a sensor, is secured with the one outer surface of the fabric at the breakout with the connector being united with the at least one exposed end of the conductive yarn.

Abstract: Disclosed are systems or apparatuses and methods for forming a junction between conductive fibers that are incorporated into a fabric. Briefly, one method includes the steps of removing insulation from two intersecting individually insulated conductive fibers to expose the individually conductive fibers, bringing the exposed individually conductive fibers into contact with each other at a junction point, and forming a molecular bond between the conductive fibers at the junction point. Also disclosed are systems for forming a junction between conductive fibers that are incorporated into a fabric.

Abstract: An energy weapon protection device to be worn by a live potential target includes a generally flexible main panel having three main elements, a generally flexible, generally planar electrically non-conductive outer insulator panel, an electrically conductive inner conductive panel and an electrically non-conductive insulating backing panel. The inner conductive panel is mounted on the insulating back panel in generally parallel alignment and the outer insulator panel is mounted on the inner conductive panel in generally parallel alignment thereby forming the main panel, and the main panel is operative to receive an electrical pulse from an energy weapon through the outer insulator panel into the inner conductive panel which completes the electric circuit for the energy weapon and the insulating backing panel generally preventing electric current from passing therethrough from the inner conductive panel such that the live potential target is protected from the electrical pulse generated by the energy weapon.

Abstract: A system and method reduce starting torque for initial rotational displacement and assure smoothness of motion for continuing displacement of a rotary joint. A rotary joint (either cylindrical or spherical) has a first annular joint member and a second annular joint member separated by a fluid-filled annulus. The second annular joint member is adapted for rotary motion with respect to the first annular joint member. A module fluidly communicating with the fluid-filled annulus creates vibratory micro motions in the fluid of the fluid-filled annulus which is between a pair of seals extending between the first annular joint member and the second annular joint member. The vibratory micro motions induce micro motions in the seals of the rotary joint. The micro motions in the seals reduce the initial torque for the initial displacement and assure smoothness of continuing displacement of either or both of the joint members.

Abstract: A wearable garment incorporates a manual interconnect device, so that a user wearing the garment can operate the interconnect device by coupling a connector, which is in turn coupled to a power source or external electronic device. Through a releasable locking action by the user, the connector is electrically coupled to the interconnect device, which is coupled to a fabric circuit integrated in the garment, such that operation of a locking action activates related ancillary equipment such as power supplies or electronic devices.

Abstract: Electric heating/warming composite fabric articles have at least a fabric layer having inner and outer surfaces, and an electric heating/warming element, formed, e.g., of die cut, metallized textile or plastic sheeting or metal foil, affixed at the inner surface of the fabric layer and adapted to generate heating/warming when connected to a power source. A barrier layer may be positioned, for example, adjacent to the inner surface of the fabric layer; e.g., with the electric heating/warming element formed thereupon, including to protect the electric circuit, e.g. against abrasion.

Abstract: An outer garment or vestment comprising a front panel and rear panel that includes an electrical circuit of neon wire, a battery operated power pack and toggle switch so as to be illuminated to allow play, such as touch football, tag and the like, in the darkness where the neon wire is mounted in a lens on the rear panel with a configuration defining a focal point such as a spiral shape and is operatively connected to the toggle switch so that depressing the lens causes the illuminated neon wire to be turned off and a portion of the neon wire mounted on the front panel and configured to designate each of the sides of the players.

Abstract: A fabric for use with a system for monitoring prescribed body functions comprising an elastic fabric, adapted to be carried by a torso, which is stretchable in its longitudinal direction so as to expand and contract in response to body movement and size. The carrier includes at least one conductive and inelastic yarn arranged longitudinally of and located between upper and lower surfaces. The conductive yarn is arranged in sinusoidal configurations longitudinally of the fabric. The conductive yarn forms a breakout through one of the outer surfaces, at selected locations along the length of the fabric, forming opposed exposed ends above the surface. A monitoring unit, which includes a connector and a sensor, is secured with the one surface at the breakout with the connector being united with the exposed ends of the conductive yarn. The fabric acts to maintain the monitoring unit in a desired stationary position allowing the sensor to sense signals emitted from the torso and transmit these senses signals.

Abstract: A hair decoration such as a kit comprises a series of beads connectable to one another and a set of appliqués. At least a portion of the beads contains one or more lights inside which are in electrical communication with one another to permit power to be commonly supplied to the lights from a battery. One or more beads includes a mechanism for attaching the beads to hair. A light circuit is coupled to the light-containing beads to drive the lights. Appliqués in the set of appliqués are selectively applicable to the beads by a user, have a transmissivity, and are in a path of illumination of the lights. As a result, when the lights are driven by the light circuit, the lights shine and provide illumination in the path. The illumination can be direct or backlit. A method of decorating hair is also provided.

Abstract: Electric blankets and methods and systems for making electric blankets are provided. Certain electric blanket embodiments include a laminated scrim blanket with a heating element embedded therein. Other embodiments provide an electric blanket formed from conductive fibers. Another embodiment includes a central circuit that controls the position of electricity to an electric blanket responsively to temperature rate of change. A further embodiment includes a machine for inserting a heating element within passageways of a blanket shell.

Abstract: Computer-aided design and manufacture software and hardware automate garment and fashion definition and production. Configurable garment includes ornamental element, pattern display, and personal identifier and wireless sensor electronics.

Abstract: A method and apparatus for selective shielding of fabric antennas incorporates the fabric antenna into the body of wearable garments and provides protection for wearers of the garment while allowing wearers to displace a portion of the garment body selectively, so as to render the antenna active or inactive. To protect wearers of the garment from the RF field that may be generated when an antenna is in use, a metallic fabric shielding layer is positioned in the body of the garment between the antenna and the body of a wearer. Another layer of metallic shielding fabric mounted to a layer of protective fabric formed as a displaceable layer of the garment body. The disclosed embodiments of the invention show displaceable layers in the form of foldable cuffs on sleeves, epaulets, decorative pocket-like flaps, and faux seams.

Abstract: A glare-protection device contains an active filtering element (11) with influenceable light transmission such as a liquid crystal cell. The glare-protection device also contains an electronic circuit (3) for evaluating the output signal of a light sensor (5) and for driving of the filtering element (11), which electronic circuit (3) is attached to the internal surface (22) of a printed circuit board (2). The electronic circuit (3) has an evaluation circuit (31) and a driving circuit (32). A screening element (4), which is made out of electrically conductive material, is provided to screen at least a part of the evaluation circuit (31) against electro-magnetic radiation originating from the driving circuit (32), and is affixed to the same internal surface (22). Thanks to the screening element (4), the evaluation circuit (31) can be designed to be exceedingly sensitive, without it being excessively interfered with by electromagnetic influences.

Abstract: A PWM-based controller for controlling a voltage applied to a DC-powered electric heating blanket from a power source includes a square wave producing circuit for connection in the circuit with the battery and the blanket. The square wave producing circuit produces a variable duty cycle square wave for controlling application of power to the blanket in accordance with the duty cycle of the square wave. The square wave producing circuit has a control input for varying the duty cycle of the square wave in response to a voltage at the control input. The voltage at the control input may be set manually using a voltage varying circuit connected to the power source. A low voltage detection circuit may also be connected to the power source and coupled to the control input of the square wave producing circuit for automatically producing a voltage that decreases the duty cycle of the square wave when the battery voltage decreases to or below a predetermined level.