Abstract: Disclosed herein are a door lock control device and method of a washing machine which sense opening or closing of a door using a door lock switch. Since the door is locked or unlocked and the closing or opening of the door is sensed using one door lock switch without adding a separate switch to sense the closing or opening of the door, cost may be decreased.

Abstract: A control circuit for an electric power circuit switch includes: a sampling/hold circuit section configured to sample a period of a detection signal of a current of an electric power system and provide a sampled signal; a discrete Fourier transforming (abbreviated as DFT) circuit section perform DFT on the one-period sampled signal to provide a magnitude and a phase of a frequency component of the current of the electric power system; a differentiator configured to differentiate the detection signal to provide a rate of change of the current over time; and a controller to determine whether to perform trip controlling according to the magnitude of the frequency component of the current from the DFT circuit section or the rate of change from the differentiator on the basis of the rate of change of the current and the reference rate of change.

Abstract: A method and system for storing information in a nonvolatile memory comprising: a substrate comprising magnetic material operatively associated therewith, the magnetic material having at least one first portion of low permeability and at least one second portion of high permeability; a reader comprising a sensor for reading information by measuring the magnetic permeability for the at least one first portion and the at least one second portion; whereby the at least one first and second portions are subjected to a magnetic probe field from one of an external source, the sensor, or a combination of an external source and the sensor.

Abstract: A method and means for controlling the operation of a machine by an operator having a transmitter mounted to a machine, a sensor attached to an operator or an operator's clothing, and a tracking device that receives signals from the sensor and determines the position of the sensor. Based on the determined position of the sensor, the tracking device sends signals to the operator and an actuator on the machine based on a comparison with a danger zone, warning zone, or operator zone.

Abstract: The invention relates to a proximity switch, particularly an inductive proximity switch, with an oscillator having an at least partly self-compensated feedback network influenceable by a target to be detected, as well as an oscillator amplifier.

Abstract: An operation section 2 is provided to a proximity sensor including: a detection section having an oscillation circuit 10; and an amplification section 2 having a function detecting a metal body using an oscillation amplitude of the oscillation circuit 10. In a set mode, when an operation to set an adjustment value for a sensitivity adjustment (a sensitivity adjustment value) is conducted in an operation section 22, CPU 20 generates a sensitivity adjustment signal in digital quantity indicating the sensitivity adjustment value and outputs the signal to a D/A converter 25. The sensitivity adjustment signal digital-to-analog converted by the D/A converter 25 is given to a feedback circuit 13 through a voltage adjustment circuit 26. Since the feedback circuit 13 is designed so as to change a feedback current quantity according to an applied voltage, a current with a magnitude matching a value the sensitivity adjustment signal is fed back to a resonance circuit 11 to thereby control an oscillation amplitude.

Abstract: In order to provide a triggering signal for a cable stripping device that is also capable of dealing with very thin wires, it is suggested to use a piezoelectric sensor, the output signal from which is forwarded to an electronic evaluation unit. The electronic evaluation unit then outputs a digital signal that enables the stripping process to be started safely. Various mechanical mechanisms are suggested to ensure that the digital signal is not triggered when not being touched. This problem is proposed to be solved by a low pass filter discriminating between sensor inputs by touching and vibration shock events, etc.

Abstract: Electronic proximity switch with a member (1) generating an alternating electromagnetic field, which is excited by an oscillator (2), an influencing of the alternating field, induced by approach of a trigger, being evaluated by an electronic signal-evaluation stag (8), including an amplifier stage (5), for emission of an output signal. The signal to be evaluated, which is obtained by a member (3, 4) influenced by the electromagnetic field, is mixed with the oscillator frequency before its evaluation.

Abstract: An apparatus and method used to detect metallized containers or other objects in closed packages traveling in a conveyor stream. The apparatus includes a pair of coil units mounted in association with a packaging conveyor such that the closed packages will pass therebetween. Appropriate field generation circuitry are connected to the coil units for producing a magnetic field. When the metallized containers pass through the magnetic field, the impedance across the coils will vary. The varying impedance is measured continuously, thus giving an indication as to whether the metallized object has been detected. If the package is nonconforming, steps can be taken to automatically remove it from the conveyor stream.

Abstract: In order to identify the position of a movable element, such as a lock bolt, a resonant circuit is subjected to the element or a part that moves with the element. The resonant circuit is thereby damped by the element in a position-dependent manner and oscillates in one end position of the element but is damped too greatly in the other end position. A microprocessor controls the switching on and the respective operating point of a transistor in such a way that switching hysteresis is obtained. The operating point can be automatically readjusted in an adaptation phase.

Abstract: A proximity switch with a magnetic field-sensitive sensor is formed of limbs of a U-shaped permanent magnet with a vertical direction of magnetization. A magnetic flux-free region, in which the sensor is fitted, is formed by three like poles. When a flat ferromagnetic triggering part is brought close to the two poles of the limbs of the U in a plane parallel to the base of the U, a switching signal which is triggered from the sensor by the cancellation of the magnetic flux-free region can be evaluated.

Abstract: An apparatus for the thermal binding of sheets includes at least one support (5-5a-5B) for a binding element (3). The binding element has a binding back on which an amount of glue (4), which melts under the influence of heat, is provided. A heating element (6) co-operating with the support (5-5A-5B) or forming part thereof, a detection device (7) to detect the presence of the binding element (3) in the apparatus (1) and a control/switching device (8), which is connected to the detection device (7) and is connected to the heating element (6) in order to switch it on and/or off, are also included. The detection device (7) is applied underneath the support (5-5A-5B).

Abstract: An apparatus to detect the presence of a surgical handpiece is provided. The handpiece is electrically isolated from its source of electric power by a transformer having two primary windings and one secondary winding. The first winding provides power to the handpiece and the second winding is used in the handpiece detection apparatus. The handpiece detection apparatus includes a detection circuit and a comparator that compares the electrical signal input to a standard to determine the presence of the handpiece.

Abstract: A safety device and an alarm system controller of a workspace providing bidirectional communication for determining whether the required safety devices are used by the work persons entering the workspace, and whether the safety devices are properly worn. The communication means used allow to associate one or more safety devices to a work person.

Abstract: A safety device and a supply power controller of a machine tool providing bidirectional communication for determining whether the safety device is appropriate for the particular machine tool, and whether the safety device is properly worn. The communication means used allow to associate one safety device to a plurality of machine tools and a plurality of safety devices to one machine tool, as well as relating safety devices to a specified work zone including a plurality of machine tools.

Abstract: A mounting base for an associated inductive proximity switch, with the mounting base having an approximately beaker-shaped plastic housing so constructed that the switching behavior of the proximity switch is independent of the respective mounting surfaces. A metal ring is disposed internally on a base bottom of the mounting base, with a diameter of the ring being approximately equal to transverse dimensions of the proximity switch. The metal ring is advantageously located in a corner area of the base bottom and a jacket surface of the mounting base.

Abstract: An electric control circuit of an electromagnetic clutch includes a relay-controlled, two-position switch which operates, in response to a power source being disconnected from the switch relay and the clutch, to establish a path to ground through which the induced voltage of the clutch may be dissipated to thereby speed up the disengagement of the clutch once power thereto is discontinued. The control circuit may be that employed in a self-propelled forage harvester equipped with a metal detector, the latter including a normally closed relay switch which opens in response to metal being sensed to thereby de-energize the clutch and two-position switch relay.

Abstract: A proximity switch circuit including first and second transistors Q4, Q6 connected as a long tail pair with an inductive sensing circuit LC connected to one leg thereof and an emitter follower circuit Q7, Q8 connected between said one leg and the base of the transistor of the other leg, whereby an oscillator circuit can be provided which is non-critically damped to enable faster speed of operation of the proximity switch.

Abstract: A proximity switch is provided which has a programmable parameter such as a programmable switching threshold and/or programmable switching function. The device is programmable using a digital signal that is applied to a conventional terminal of the proximity switch. For example, the conventional power signal for operating the proximity switch can be modulated by a programming signal for use in programming the proximity switch parameters. The program signal could also be input to a conventional output terminal of the proximity switch.

Abstract: An electronic switching device such as an inductive proximity switch includes an externally influenced oscillator detector with its output connected to a switching amplifier. An electronic switch connected to the output of the switching amplifier responds to the amplifier signal and controls a state indicator. Upon the influence state of the detector crossing a predetermined threshold, the switching state of the electronic switch is reversed, and the detection state of the oscillator is reflected in switching states of the electronic switch and indicated by the state indicator. A second state indicator indicates whether or not the reading from the oscillator is in a "safe range" in which variations in ambient conditions cannot cause a false reading.

Abstract: Detector comprising a sensor and a processing circuit connected to a load by means of two wires. Two switches (I1, I2) are arranged in series in a switching circuit leg (21), the ends of which (C, D) are connected to the detector terminals and the middle point (S) to a terminal (F) of the processing circuit. When operating (I1) is conductive and (I2) determines a parallel regulation of the voltage (V) at the processing circuit (12) terminals ; when in rest position, (I1) determines a series regulation of the voltage while (I2) is blocked.

Abstract: A bar code scanner which is responsive to the movement of the scanner to activate its light source. The scanner includes a motor having a moving member which is set in motion when the scanner is displaced from a rest position. The moving member generates a voltage in a coil, which activates the operation of the bar code scanner.

Abstract: Devices and methods are disclosed for controlling the dispensing of fluid, particularly hazardous or flammable fluids, such as automobile gasoline. A recurring problem is the dispensing, particularly by untrained members of the public, into unsuitable or unapproved containers or into no container at all, which can cause leakage, fire, damage to the container, or environmental or health hazards. The invention detects the presence of a container closely adjacent to the outlet of the pump or other dispenser and attempts to determine whether a detected container is of a suitable type by generating a field, such as an electromagnetic field, and measuring the reaction of the container to the field, thus identifying information about selected physical characteristics of the container, such as its metallic or non-metallic material composition. Unless a suitable container is detected in a predetermined position, the invention will block dispensing of the fluid.

Abstract: A detector having a housing (12), a mounting (3) which is able to adopt four orientations relative to the housing (12), and a detector head (4) which is able to adopt, relative to the mounting (3), two orientations in one of which a sensitive face (29) of the head is oriented laterally relative to the axis (Z) of the housing (12), while in the other orientation the sensitive face (29) is centered on the axis (Z). The mounting (3), which can be separated from the housing (12), can engage through either of two recessed faces (33, 34) of the head, by the sliding of slideways (56) of the mounting between a base (38) and protuberances (43) of the head. The position of association of the head relative to the mounting is defined by the abutment of faces (48) of the protuberances (43) against stop faces (57) of the mounting. A pivot (18) of the mounting is then fixed in an aperture (22 ) of the housing. This mounting is used in order to eliminate screw fixings.

Abstract: A system for automatically detecting the presence of staples within a set of original document sheets loaded into a document handling tray and automatically inhibiting the operation of the document feeder to prevent damage to the document feeder or the original sheets in response to detecting a staple, particularly a staple in a preselected area of the document tray in which it is most likely that a staple would be present as documents are normally loaded into the document tray by the operator, including preventing inadvertent actuation or output of the staple detector by metal objects other than a staple, such as an operator's ring temporarily present in the document tray during initial loading the documents, preferably by coordinated confirmation of the completion of document loading into the document tray.

Abstract: An oscillation circuit of a proximity switch includes a parallel LC resonance circuit (L, C), an oscillation transistor (Tr6) controlled by an output voltage from the resonance circuit for switching a constant current and a feedback circuit (Tr2, Tr3) for feeding back a current flowing through the oscillation transistor to the resonance circuit. In the circuit, there is further disposed a feedback current increase circuit including a second transistor (Tr7) controlled by an output voltage from the resonance circuit and a resistor (R) connected in series to the second transistor. The resonance circuit is supplied via the feedback circuit with a feedback current obtained by adding a current flowing through the feedback current increase circuit and a current passing through the oscillation transistor, thereby developing a large change in the amplitude of the oscillation.

Abstract: A proximity switch assembly (10) for signaling the location of a movable member (36) at either of opposite end limits of movement relative to a stationary frame (44,46) includes a compact elongate housing (58) adapted to be mounted on the frame to extend along the path of movement of a power driven member (32), such as the piston rod of a hydraulic cylinder, which shifts the movable member between its end limits. The proximity switch is fixedly mounted in the housing and carries a switch actuating member (74) mounted for sliding movement over a relatively short distance sufficient to move two actuating targets (104,106) into an out of actuating proximity of respective air core proximity sensing coils (132,134) within the housing. Lost motion abutment structure (76,78) on the switch actuation member and power driven member (54) move into engagement with each other as a power driven member approaches each end of its stroke.

Abstract: The invention relates to an apparatus consisting of a device for generating a magnetic field mounted for movement relative to a product sitting in or moving through its field which is suspected of carrying at least one metal component which will cause the generator to move either toward or away therefrom because of either the attractive or repulsive forces, or both, caused by the presence of this metal or these metals. A load-responsive element in the form of a load cell is connected to the field generator so as to sense its movememnt if any and output a signal evidencing such movement. A detector is connected to receive the output signal from the load cell and use this information to initiate an appropriate response to the presence of the metal or metals causing the displacement of the generator.

Abstract: A proximity switch immune to interference fields includes an oscillator circuit (1) that can be influenced by a permanent magnet, this circuit being damped in the basic condition by a core of a coil (13), which core consists of an amorphous metal, and being undampable by the approach of the permanent magnet. In order to prevent triggering of the proximity switch by a magnetic alternating field, a signal evaluating circuit (2), yielding a switching signal corresponding to the undamped condition of the oscillator circuit (1), and a signal evaluating circuit (8) are connected to the oscillator circuit output (17). The signal evaluating circuit (8) detects an output signal produced by a magnetic alternating field separately as interference and blocks, by way of a blockable holding circuit (5), the switching signal path so long as a magnetic alternating field is present.

Abstract: A device having a detector element for detecting small particles of metal moving in a stream of particulate matter, such as tobacco filler. The detector element is a coil through which the stream passes. The coil is the inductor of an oscillating circuit and is also part of the negative feedback loop of an operational amplifier. Inductance changes caused by the presence of metal become impedance changes that alter the amplifier gain, changing the amplitude of the AC component of an alternating current output signal. The signal peaks are shifted further, increasing detector amplitude, by coupling the signal through a capacitor to a source of potential so that the DC component of the signal also changes as the change in inductance allows current to flow through the capacitor.

Abstract: A proximity switch has at least three Hall effect magnetic field sensitive transducers mounted in a transducer housing and has at least two magnets mounted in a magnet housing. The transucers produce logic signals, and a logic circuit responsive to these logic signals activates an electrical switch only when the magnets are in a proper position relative to the transducers. The electrical switch may be used to control a machine, and the machine is not activated until the proximity switch is activated.

Abstract: A non-contact proximity switch with an oscillation circuit (L 1, C 1) which is activated in a step-like manner, has a reference voltage source (6) which produces at least one reference voltage level (U.sub.ref) and has at least one comparator (5) which compares the amplitude of the transient response with the associated reference voltage level (U.sub.ref) in order to be able to detect at least one value that is distinctive for the time curve of the decaying oscillation from at least one transient response of the oscillation circuit (L 1, C 1) after such an activation. At least one counter (7, 10) counts, at least within a portion of the decay period of the transient response, the number (DA) of the half-waves of the transient response, the peak of which deviated from the associated reference voltage level (U.sub.ref) in one of the two directions.

Abstract: To detect if a tool bit, such as a drill, a saw blade, or the like, upon being worked into a wall, meets a metallic obstruction, such as a conduit, reinforcement rod, hydraulic pipe or the like, an alternating voltage, preferably between 2 and 20 kHz, is coupled through a coupling capacitor (9) to the tool bit, and current flow to the tool bit is detected by a current measurement stage (10; 31, 32) to disconnect energy to the drive motor (5), for example by disabling firing of a thyristor (15), or closing a valve of a compressed-air tool. The coupling capacitor should have a capacity small enough to provide high impedance to network power frequency, and to insure a substantial change in current being supplied to the tool bit holder, typically a chuck, if the tool bit meets a metallic object in the wall.

Abstract: To detect impending deropement of a wire haul rope from supporting sheaves in an aerial tramway system, there is provided a magnetic assembly having sufficient field strength to support itself in a predetermined position by reason of attraction to the wire haul rope when running normally in the sheaves. When the wire haul rope begins to run off one of the sheaves toward an impending deropement, the magnetic assembly will fall from its armed position to a substantially moved position. The magnetic assembly carries at least one position-responsive switch which interrupts a detection circuit when the magnet moves to the moved position. The interruption of the detection circuit is utilized to detect the location of the potential deropement and to terminate tramway operation.

Abstract: An electronic sensor of the contactless type has a free-running oscillator with internal positive feedback supplemented by an external negative feedback including a capacitive path whose impedance is normally high but is lowered in the presence of an object to be detected, thereby reducing the output signal of the oscillator from a normal amplitude above a predetermined level to a diminished amplitude below that level. The negative feedback is provided through an IGFET, e.g. of n-channel depletion type, with the aid of a capacitor bridging its source and gate electrodes to form with the external capacitance a voltage divider for the output signal of the oscillator.

Abstract: A high frequency oscillation type proximity switch, being an approach switch adapted for detecting the approach to or departure from the detector coil of a metal body, based on the change in output of the high frequency oscillator circuit, with the oscillator coil of the oscillator circuit as the detector coil, in which a small-diameter housing case is inserted in the cable interconnecting the detector head and the power source, the printed substrate for use as the signal detector circuit is provided in housing case and the housing case is filled with an insulation resin.

Abstract: An electrical interlock to prevent unauthorized access to potentially hazardous equipment and an associated detection circuit to detect if a safety shield or closure member is open, not securely closed or has been tampered with and to thereupon automatically de-energize the equipment. The detection circuit may comprise a balanced bridge incorporating the electrical interlock into a leg thereof and may also provide a visual or audible indication whenever the bridge is unbalanced thereby indicating an improperly closed safety shield.

Abstract: The invention relates to an inductive proximity switch having a feeler head with a feeler coil as a component of an LC oscillator circuit of a high frequency oscillator, the feeler head serving to generate a directionally oriented, alternating magnetic field, whereby the feeler coil of the feeler head is coupled with a closed circuit loop comprising an inductance and an ohmic resistance such that the oscillator is damped when the field is undisturbed and its damping is reduced when the field is disturbed by a nonmagnetic object such that an oscillation occurs.

Abstract: An electrical circuit, the starting circuit for a motor vehicle for example, is selectively enabled by a control circuit which includes a magnetic field responsive switching device. Proper positioning of a magnet which provides a field of the appropriate polarity and strength relative to the switching device results in the energization of a relay which has contacts connected in series with the circuit being controlled. In the motor vehicle application, operation of the ignition switch within a pre-determined time subsequent to removal of the magnet will latch the relay in the energized state.

Abstract: A sensor assembly for electrically signalling the presence of bare spots on coated sheet metal for removal before further fabrication.

Abstract: Liquid flow sensing apparatus which in the illustrative embodiment is used to sense an occluded vein (cessation of blood flow). A flexible pressure pillow is connected in the blood flow line and is inserted into a housing in contact with a metallic leaf spring. The position of the leaf spring is adjusted relative to an eddy current proximity sensor so that the sensing apparatus is calibrated to a no-alarm position during proper blood flow. If blood flow ceases, the flexible pressure pillow contracts thereby moving the leaf spring away from the eddy current proximity sensor and an alarm condition is thereby detected.

Abstract: A conductive object detector having an eddy current killed oscillator, wherein the oscillator output is stabilized by means of a proportional plus integral controller. The controller proportional gain is set low and the integral time long, hence a conductive object near the oscillator will "kill" it, whereas the controller will minimize the effect of temperature or aging on the oscillator output.

Abstract: A proximity detector has permanent magnets positioned within a chassis so that the axis and poles of the flux field of the permanent magnet are substantially normal to the front of the chassis. A switch is positioned along the front of the chassis proximate the magnet. The switch has contacts operable by the magnetic flux field of the magnet. A shield is positioned between the magnet and the rear of the chassis and between the switch and the rear of the chassis. The shield acts to inhibit extraneous magnetic fields from interferring with the detector operation and as a magnetic conductor to focus the magnetic flux field. The flux field of the permanent magnet is modified by a ferromagnetic object positioned at a predetermined distance from the front of the chassis to cause the contacts of the switch to operate in relation to the positioning thereof and in turn send an operate signal indicative of the positioning of the ferromagnetic object at the front of the switch to an external circuit.

Abstract: A contactless motion detector, such as an oscillator sensitive to an approaching metallic element, is connected across a storage capacitor which can be charged from a source of pulsating direct current through a constant-current unit whose current flow is throttled when the charging voltage of the capacitor reaches a predetermined level. A thyristor connected across the series combination of storage capacitor and constant-current unit has a gate connected to a tap on a voltage divider lying in parallel with the capacitor so as to fire when the capacitor voltage rises substantially above the aforementioned level in order to break down a Zener diode forming part of that divider. Such a rise occurs when a transistor, inserted between the capacitor and a higher-voltage output of the constant-current unit, is turned on by a switching transistor responsive to a trigger signal from the detector.

Abstract: A magnetic proximity sensing apparatus for sensing ferro-magnetic objects is especially well adapted for use with fluid cylinders having pistons formed from magnetically attracted material. The apparatus includes a magnetic actuator responsive to the proximity of the fluid cylinder piston or other ferro-magnetic object which closes a switch and enables electrical circuitry for controlling fluid valves or other apparatus. A reed switch mounted within a hollow, cylindrical, permanent magnet has a separate pole piece secured at one end of the reed switch. The proximity of a ferro-magnetic object changes the flux within the magnet, closing the reed switch. The circuitry is solid state and includes a silicon controlled rectifier acting as a gated switch for completing the circuit.

Abstract: A magnetic proximity sensing apparatus for sensing ferro-magnetic objects is especially well adapted for use with fluid cylinders having pistons formed from magnetically attracted material. The apparatus includes a magnetic actuator responsive to the proximity of the fluid cylinder piston or other ferro-magnetic object which closes a switch and enables electrical circuitry for controlling fluid valves or other apparatus. A reed switch mounted within a hollow, cylindrical, permanent magnet has a separate pole piece secured at one end of the reed switch. The proximity of a ferro-magnetic object changes the flux within the magnet, closing the reed switch. The circuitry is solid state and includes a silicon controlled rectifier acting as a gated switch for completing the circuit.

Abstract: A proximity switch is connected to close a circuit between a source and a load when a metal object is adjacent to a coil in the switch. The coil is part of an oscillator circuit that is selected to have its output damped below a selected amplitude when the metal object is close enough to the coil. The reduced amplitude of oscillation opens a capacitor shunting switch thereby permitting the capacitor to be charged. The charging of the capacitor to a selected level turns on an SCR to connect the load to the source through the SCR. A power storage circuit has a capacitor that is charged when the SCR is turned off to provide operating current for the circuits of the switch when it is not available because the SCR is turned on to shunt the current from the main power source.

Abstract: A contactless motion detector is energized from a source of direct current via a pair of supply leads and delivers an output signal by way of a further conductor to a control electrode of a binary electronic switch, such as a thyristor, in series with the source and a load to modify the flow of load current upon the approach of a metallic element, for example. An Exclusive-OR gate is inserted in the further conductor to act as a selective signal inverter, one input of this gate being permanently connected to one supply lead while being also selectively connectable to the other supply lead whereby the load current can be either increased or reduced upon the occurrence of the event to be detected.

Abstract: A control system for a laundry machine generates a control signal to operate a door lock unit and prevent the door from opening while the laundry machine cylinder is rotating. A permanent magnet is mounted adjacent to the drive wheel of the cylinder so that the wheel spokes cut through the magnetic field of the magnet. A pick-up coil is mounted coaxial with the magnet and generates an induced pulse signal as the wheel turns. The induced pulse signal is processed by circuitry mounted on a printed circuit board to generate a DC control signal for the door unlocking circuitry of the door lock unit. The pulse signal is rectified and smoothed to provide a DC signal and is processed by a timer circuit to provide an amplified, precise switching signal which is used as the control signal. The DC control signal operates an electronic switch which connects an AC power source across a relay coil to open the door unlocking circuit so that the door remains locked as long as the DC control signal is generated.

Abstract: A high frequency pickoff is disclosed having two spaced inductors electrically connected in series and a capacitor connected in parallel with the inductors, thereby forming a parallel resonant circuit. A conducting member is mounted for motion in the space between the two inductors. A pair of transistors are mounted in push/pull configuration to alternately connect first one end and then the other of the resonant circuit to a source of electrical energy. The source disclosed is a current source for matching the high impedance of the parallel resonant circuit. When the electrical energy is switched at substantially the resonant frequency of the parallel circuit, differential motion of the conducting member relative to the inductors provides differential amplitude output at the frequency of resonance of electrically opposed ends of the resonant circuit.