Abstract: This invention concerns an inductive proximity switch having an oscillator and a resonant circuit which is dampable by outside objects, as well as an electronic switch controllable by the voltage across the resonant circuit. From the signal of the electronic switch a switching hysteresis is derived. A device for changing the frequency, when the resonant circuit is damped, as a function of the signal of the electronic switch allows the adjustment of the hysteresis in such a way that there is essentially no effect on the sensitivity of the oscillator.

Abstract: A film or photo print inspection machine having a print-advancing drive means to run a strip or web of photo prints from at least one supply reel to a corresponding collecting reel, over a viewing surface, is provided with a presence switch means activated by a capacitance reactive sensor or sensing antenna, the antenna being comprised of a metal plate mounted on the rear of the viewing surface such that introduction of an operating technician's hand, or other impedance, into a sensing region established by the antenna, in order to mark a defective photographic print, will activate the presence switch means to turn off the print-advancing drive means. Print advancement resumes when the technician's hand, or other object, is withdrawn from the antenna sensing region.

Abstract: A wire detector for semi-automatic wire stripper which responds to capacitance changes caused by sensing a capacitive object such as an exposed wire end and includes signal processing through an oscillator and amplifier circuit providing timer control for activating a relay driver circuit for an adjustable duration time period. The wire touch sensor circuit relay driver is then coupled through a mercury wetted relay which provides electrical isolation from external (switched) voltages to an air solenoid which, when actuated, allows the pneumatic mechanism of the wire stripper to cycle through its function of wire stripping.

Abstract: A plumb bob (11) having an upwardly extending tube (12) is located in a support tube (10) having grooves (20) in which are laid sheathed cables (22). The support tube (10) has windows (21) across groups of which pass the bare conductor elements (23) of the cables (22). The upwardly extending tube (12) forms an energizing electrode and the bare conductor elements (23) form two pairs of orthogonally disposed electrodes (30) capacitatively related to the electrode formed by the upwardly extending tube (12). Horizontal movement of the support (10), and hence any structure in which it is located, creates a capacitative charge between the electrodes which allows the movement to be measured in magnitude and direction. The apparatus has one application to the measurement of horizontal movement in a liquid metal cooled nuclear reactor.

Abstract: A touch plate switch is used to energize an industrial machine. The switch is closed by mere contact of the touch plate by an operator's hand. No physical movement of the plate is required. As a consequence, the risk of the operator developing carpal tunnel syndrome is substantially eliminated. By providing two such touch plate switches for operating relay switches connected in series, both switches must be simultaneously operated to start the industrial machine. By separating the switches a distance sufficient to prevent operation of both switches by one hand, the operator must use both hands and thereby a further safety feature is realized in that one of the operator's hands will not be inadvertently damaged by the machine.

Abstract: A touch switch device includes a touch plate 3 or other touch member arranged, when touched, to interrupt the passage of an oscillating signal from a DC powered oscillator 31-34 to a charging circuit 36-39, including a capacitative store 38. The charging circuit responds to this interruption to initiate discharge of the charge store, and a control, including an inverter 44 and a flip-flop 46 controls a switch 48 to change from one state to another upon a change of charge state, in this case a recharge, of the charge store. A circuit 51-54 supplies a reset signal to the flip-flop during an initial preset period immediately following the switching on of power to the device, to inhibit this change of state of the switch 48 during such period.

Abstract: Apparatus is disclosed for arresting the motion of a motor driven panel wherein an electrical conductor along an exposed edge of the panel is connected to an electrical sensing circuit. The presence of an object in contact with the electrical conductor is sensed by the sensing circuit, which then operates a switching device. The switching device disconnects drive power to the motor, preventing motion of the panel for as long as the object is in contact with the electrical conductor.

Abstract: A control circuit for use with an electronic guard strip for preventing collision of the strip with a moving object. A control such as a relay, is connected to at least one antenna, which antenna forms a capacitor together with a base in its ambiance. A voltage generator conducts an alternating voltage to the antenna. The control and the antenna are connected in circuit relation to an amplifier. A change of voltage arising from any capacitive protuberation in the antenna is conducted to the control. The voltage from the amplifier is conducted through a rectifier to another amplifier that is connected so as to have its direct current gain as +1, but which amplifies any change of voltage occurring in the d.c. voltage input to a multiple and which further acts upon the control through a comparator.

Abstract: This invention is concerned with an electronic control system that uses a common two wire lead with a plurality of detector units connected in parallel thereto in order to control a plurality of electrical loads. The common two wire lead is connected to a single master controller. Control modules or control elements have RF signals matched individually to each detector are mounted on the controller and move the loads coupled to each detector. This system finds great acceptance in regulating solenoid motors such as found in model railroad train layouts.

Abstract: A touch sensitive control panel is disclosed which is constructed of a support surface and a graphic display member secured thereto. The support surface has regions of conductive material deposited thereon and the graphic display member has functional indicia printed thereon, there being a layer of adhesive intermediate the graphic display member and the support surface to secure the graphic display member to the support surface with the functional indicia in registration with the conductive material regions. The graphic display member and the adhesive layer form a dielectric medium between the conductive material and a body portion of an operator touching the front surface of the graphic display member. An improved method for manufacturing such a touch panel is also disclosed.

Abstract: An electronic pressure switch composed of a flexible diaphragm carrying a conductive plate and two axially displaceable electronic proximity switch members each disposed at a respective opposite side of the diaphragm, each switch member being arranged to be actuated upon movement of the plate to within a predetermined distance therefrom, under the action of a pressure medium acting on one side of the diaphragm.

Abstract: A proximity detector comprises a pair of antennae being disposed along the front edge of a door and at a space therebetween, a pair of coils constituting series resonance circuits, together with each electrostatic capacities of the antennae which are connected in series with the coils, an AC power source for supplying voltages to the series resonance circuits; rectifying circuits for rectifying the voltages produced on the antennae by the AC power source, and a differential amplifier circuit for amplifying difference between the outputs of the rectifying circuits, the output of the differential amplifier controlling the movement of the door.

Abstract: In a touch control system including one or more touch sensitive devices which capacitively transmit a relatively large electrical signal when not touched and transmit a relatively small electrical signal when touched an improved means for detecting the touch and no-touch conditions of the touch sensitive devices includes a comparator having positive feedback associated therewith. By increasing or decreasing the positive feedback the touch control system is operable either asynchronously or synchronously with an external control system. Furthermore, a plurality of touch sensitive devices may be multiplexed utilizing a single detection means constructed in accordance with the invention disclosed herein while requiring a relatively low voltage drive signal.

Abstract: A touch-actuated electronic switch is disclosed including a direct current or voltage supply having its output or common terminal connected to a voltage source which is alternating with respect to Earth ground, two signal inputs, at least one touch surface, means for connecting the touch surface to one of the signal inputs, an amplifying device and a network for imposing part of the signal found on the signal inputs onto the amplifying device. A mode of operation is disclosed wherein the amplifying device is allowed to float up and down in voltage to follow in part the alternating voltage of the signal inputs. The above arrangement can be used, through the addition of additional circuitry, to switch the power to a load on and off any time the touch surface is first touched.

Abstract: This invention is concerned with an electronic control system that uses a common two wire lead with a plurality of detector units connected in parallel thereto in order to control a plurality of electrical loads. The common two wire lead is connected to a single master controller. Control modules RF matched individually to each detector are mounted on the controller and move the loads coupled to each detector. This system finds great acceptance in regulating solenoid motors such as found in model railroad train layouts.

Abstract: An electrically powered instrument having a handle which is adapted to be engaged by the hand of a user during the utilization of the instrument can include a switch-type structure which is actuated by the mere engagement of the hand with the handle without any physical or mechanical motion occurring. The switch includes electrodes extending along the handle which are electrically insulated from one another and which are located in such a manner that they are electrically connected through the user's hand when the hand engages the handle. The switch also includes a power source or supply for applying a voltage between the electrodes and a discriminating or detection structure for detecting the change in the electrical resistance between the electrodes occurring either when the handle is engaged by the hand of the user or when the handle is released by the hand of the user.

Abstract: A user input/output device comprises a lighted, segmented bar graph type display and an array of light transmitting touch sensitive areas superimposed over the bar graph display. A suitable circuit means is responsive to the touch sensitive areas and connected for driving the segments of the bar graph such that when any one of the touch sensitive areas is touched, a corresponding display segment and all display segments to one side are energized and the remaining display elements are de-energized.

Abstract: In one embodiment, the amount of power delivered to a load depends upon the length of time a touch switch is actuated or on the number of times it is actuated. In a second embodiment, the power delivered to a load starts at one level and smoothly changes to a second level. Both embodiments include a zero-crossover detector, an a.c. operated load, and a circuit responsive both to zero-crossover pulses and to a circuit actuated by the touch switch for controlling the portion during each half period of the a.c. during which power is applied to the load.